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Comments from CNX Construction

When you do something for the first time in the world, you never attain a perfect product or solution from the start. At the Phi Suea House, we are the first to design and implement an off-grid energy system using hydrogen energy storage technology for a multi-house residence. Since day one we have been collecting monitoring data and maintaining the system. We try to contribute in advancing these systems around the world by enabling technological improvements through our experiences and by getting the word out.

It has now been two years since we bought our first machines, and when monitoring the worldwide market, there are already new and improved versions of our hardware as well as other competitive products available. The latest change of module in July 2016 brought the newest version of the electrolyser to our system.

The project has shown that the technology is ready for larger rollouts and we are sure that it will find widespread adoption – first, in the project market, and soon after in the end-user market. Please feel free to contact us in case any questions arise.

This printed version was updated on the 15th of July, 2016. We will have some updated versions or comments available on our website from time to time.

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ABSTRACT

This report shall detail the inner workings of the energy system using a hydrogen energy storage at the Phi Suea House Project in Chiang Mai, Thailand (www.phisueahouse.com). The system is the world’s first multi-house compound using hydrogen as the primary form of energy storage. The reader shall be introduced to the project concept and given a technical overview on the micro-grid energy system which has been designed to function completely off-grid, supplying power from solar and hydrogen to our state of the art designed homes without making any compromises in energy use for 21st century living. Since the energy system was first made operational in February 2015 with an initial trial period of ten months, data has been collected from three principal points, the Heliocentris/Acta hydrogen energy system, the photovoltaic system and the Multicluster energy distribution system. This data will be used to demonstrate the functionality and potential of hydrogen energy storage whilst also highlighting failings and defects of the systems current design and of its individual components.

PREFACE

The report has been researched and authored by Jan-Justus Schmidt of Germany and Alexandros Moran of Ireland. Jan-Justus has been the lead engineer for the Phi Suea House Project since its inception and has gained vast experience in renewable energy systems and hydrogen technology over this period. He has a Master of Aerospace Engineering from the University of Sheffield and he will begin his MBA at HKUST, Hong Kong, in August this year. Alexandros is originally from a civil engineering and project management background and in the past year he has shifted his focus towards clean energy projects. He is currently preparing to further his studies with a masters in renewable energy technologies in the UK.

The authors have no relationship to the manufacturing company of the hydrogen energy conversion products used at the Phi Suea House Project and their position for the writing of this report is completely impartial. Since the installation of the hydrogen energy conversion boxes, the original manufacturing company – ACTA S.p.A. (AIM: ACTA) - has been acquired and all sales have been taken over by Heliocentris Italy, a 100% daughter company of the Heliocentris AG (H2FA). To try and avoid confusion, throughout this paper the Heliocentris name will be used when making reference to the manufacturers and their support services while the term ACTA Power box (AP box), the product name, will be used when making specific reference to the hydrogen energy conversion machines.

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Table of Contents

1. Introduction to the Phi Suea House Project ............................................................................ 4

1.1 Photovoltaic System and Inverters .................................................................................. 5

1.2 Energy Management Facility (EMF) ................................................................................ 7

1.3 The Control Room ............................................................................................................ 8

1.4 The Hydrogen Room ...................................................................................................... 13

1.5 The Battery Room .......................................................................................................... 15

2. Introduction to Data ............................................................................................................... 17

2.1 Heliocentris Data ............................................................................................................ 18

2.2 Other Data ...................................................................................................................... 21

3. Operations, Errors and Maintenance .................................................................................... 22

3.1 Analysis of Timeline ....................................................................................................... 27

3.2 Error Codes .................................................................................................................... 31

4. Examples and Analysis of System Energy Management ..................................................... 35

4.1. Energy Production and Management 28th April 2015 .................................................. 35

4.2 Malfunctioning System 21st of May and 27th of May 2015 ............................................. 39

4.3 Energy Production and Management 16th of March-18th of March ................................ 56

5. Conclusions and Recommendations..................................................................................... 63

5.1 Hardware ........................................................................................................................ 63

5.2 Monitoring System.......................................................................................................... 64

5.3 Control System ............................................................................................................... 65

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1. Introduction to the Phi Suea House Project The Phi Suea House project is located on the outskirts of Chiang Mai in the north of Thailand. The vision for the project was to build the world's first multi house micro-grid energy system using hydrogen technology as a foundation for energy storage; to demonstrate its potential and to inspire the next generation of community development designers to usher in a new era of clean energy management solutions. The primary goal of this off-grid project is to drastically reduce the environmental impact caused by modern living lifestyles, whilst empowering the community’s tenants to live with a clear environmental conscience as independently as possible from state infrastructure. This is achieved by a combination of capturing, storing and managing solar energy, developing an irrigation and grey water collection and treatment system, refining energy efficient building design and by creating an organic farming space irrigated by the reused water previously treated on-site. The complex currently consists of the primary home and kitchen with a combined living area of 937 m2, two guesthouses of 258 m2 each, a workshop with an area of 79.2m2, an energy management facility (EMF) with a footprint of 92m2, a twenty five by seven meter swimming pool, a central water collection system with a 1000 m3 water tank with aeration and filter systems and pump systems for irrigation supply, a permaculture garden with an 800 m3 fish pond including two pumped waterfalls, and a pumped well with another smaller filtering system. All of the energy required for Phi Suea House is harnessed using arrays of photovoltaic (PV) panels producing a combined power of 86 KW of peak capacity. These have been fitted to the roofs of the Main House, Guesthouses A, Guesthouse B and the Energy Management Facility. Solar inverters fitted with each PV array convert the generated DC electricity to AC and feed it directly through an underground wiring network to the Energy Management Facility. From this point, depending on where power is required at a given time, the main AC distribution box will direct energy to: the load distribution box for immediate energy to the various locations on site; the Heliocentris electrolysers to convert water to hydrogen and oxygen where the hydrogen is stored in tanks for later use in the hydrogen fuel cell; the battery bank which is used during periods of transition from photovoltaic energy to hydrogen energy as well as peaks when the load exceeds the maximum output from the hydrogen fuel cells.

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1.1 Photovoltaic System and Inverters As previously mentioned, solar energy is captured through the four PV arrays fixed to the roofs of the Main House, Guest House A, Guest House B and the Energy Management Facility. In addition to the PV roof, two SMA Tripower solar inverters for DC to AC electricity conversion are also installed in each building, maximising transmission efficiency to the Energy Management Facility. The EMF has an array of 75 large 72-cell monocrystalline panels, each producing 330W, with a peak output of 24.75 kW. These panels using Taiwanese cells were produced by Chinese manufacturer Millionsun Energy Co., Ltd, based in Shenzhen. An SMA Tripower 12000TL-10 and an SMA Tripower 15000TL-10 are installed in the EMF.

Figure 1.1.1 Energy management facility with solar array

Guest Houses A and B have identical PV systems consisting of arrays of 64 monocrystalline panels, each producing 315 W. The peak power output of the solar roofs is 20.16 kW. These panels were also produced by Millionsun Energy. The Guest Houses each have two SMA Tripower 12000TL-10 inverters installed.

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The Energy Management Facility and the Guest Houses are facing due South and the solar roofs have an inclination of nineteen degrees, resulting in the highest average yield over the entire year for a fixed angle system in Chiang Mai. The Main House’s solar array consists of 84 locally produced 250 W polycrystalline panels to theoretically produce a peak power output of 21 kW. The panels are mounted flat on the roof for aesthetic reasons but with three degrees of inclination to allow water and dirt to run off. The panels are manufactured in "Pornjaroen’s" newly opened factory situated in Lamphun just outside of Chiang Mai. An SMA Tripower 9000TL-20 and an SMA Tripower 12000TL-20 are installed in the Main House. Running independently of the micro-grid are two separate PV pumping systems. The first consists of an array of twenty-four 250 W solar panels powering a solar pump for the pond waterfall. The second is a 9 kW array consisting of thirty-six 250 W panels. Twelve panels power a swimming pool pump, the remaining 24 will be connected to a well pump in July 2016.

Figure 1.1.2 PV arrays at Phi Suea House

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Sunny Tripower Model

Input Max DC Power (kW)

Input Max Voltage (V)

Output Max AC Power (kW)

Nominal AC Voltage (V)

AC Grid Frequency (Hz)

9000TL-20 9.225 1000 9 3 / N / PE; 230 / 400 V 50 / 60 12000TL-20 12.275 1000 12 3 / N / PE; 230 / 400 V 50 / 60 12000TL-10 12.25 1000 12 3 / N / PE; 230 / 400 V 50 /60 15000TL-10 15.34 1000 15 3 / N / PE; 230 / 400 V 50 / 60

Table 1.1.1 Sunny Tripower inverter specifications

1.2 Energy Management Facility (EMF)

All of the energy collected by the PV system is directed to the Energy Management Facility which is divided into three rooms: the Control Room, the Hydrogen Room, and the Battery Room.

Figure 1.2.1 Energy Management Facility Plan

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Figure 1.2.2 Energy Management Facility 3-D visualization

1.3 The Control Room

The control room is where energy is autonomously managed throughout the course of each day, distributing it to the Phi Suea House loads, the hydrogen electrolysers and the battery bank during periods of PV power production; and delivering it from the hydrogen tanks and battery banks to supply the Phi Suea House loads when there is little or no PV power being produced. These two different phases of energy flow can be seen in figure 1.3.1 and 1.3.3.

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Figure 1.3.1 Energy flow diagram during periods of Photovoltaic energy production

In figure 1.3.1, sunlight is producing electrical energy in the PV modules. The energy flows from the four different PV sources into the PV distribution box where it merges into a single output before flowing into the Multicluster box. At this point, depending on the live load demand and the amount of total being produced, energy will be directed to the load distribution box and to the Sunny Island battery inverters.

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Figure 1.3.2 Multicluster and Load Distribution boxes

The load distribution box will take priority in receiving power ahead of the battery inverters so that electricity can get to locations where it is immediately required on site. After these load requirements are met, any surplus in the energy being generated by the PV system can be stored in the batteries and in the hydrogen storage system. The direction in which this excess energy flows is based on set conditions which depend on the quantities of excess produced and on the state of charge in the batteries. Because the Phi Suea House energy system was in testing phase for most of the operational lifetime up to now, and in an effort to try and find the most practical and efficient system automation, the starting conditions for the electrolysers and fuel cells have changed several times since the energy system has been activated in February 2015. The most important and omnipresent condition is that the electrolysers and fuel cells are never operating at the same time. The rest of the conditions described below are the most recent that have been programmed into the system and are the product of the successes and failures of earlier iterations. Moving into the future, these conditions are liable to change again as attempts to improve the efficiency of autonomy continue.

The first condition is that the batteries will initially receive any surplus energy being produced until the voltage across them increases to 50 V. When battery voltage is less than 50V, the electrolysers will not start – the energy will first be used to supply the loads across the site, and then to supply the six Sunny Island battery inverters. The

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battery inverters change the AC power back to DC to charge the batteries. Once these reach the 50 V threshold, the second condition comes into effect.

The second condition is triggered after the batteries are charged and when the solar irradiation reaches a minimum value of 250 W/m2. The irradiation is measured by a dedicated sensor located on the roof of the EMF and connected directly to one of the two Heliocentris energy conversion boxes. Once the load demand is being met, the batteries are over the threshold, and the irradiation is at the minimum required level, the electrolysers in the hydrogen room will be activated and the conversion of water to hydrogen and oxygen will commence, with the hydrogen being stored for later use. The electrolysers will then shut down as soon as the suns irradiation levels go below 250 w/m2 or after the battery voltage decreases to below 50 V causing a "low battery alarm" state. This prevents the electrolysers from producing hydrogen until the batteries are charged and the sun is shining again.

Figure 1.3.3 Energy Flow diagram during periods of hydrogen energy production

Figure 1.3.3 visualises the energy flow at night when no energy is being produced by the PV system. In this situation, as the energy being supplied by the PV system reduces, the Sunny Island inverters begin to take energy from the batteries and convert it back to AC, delivering it to the Multicluster box and onto the load distribution box. As soon as the battery banks' voltages go below 48.3 V or below 48.8 V for a period of 300 seconds, the two hydrogen fuel cells will be activated producing a combined maximum 4kW of power.

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The fuel cells produce DC electricity which must also be converted to AC in the Sunny Island battery inverters before being delivered to the Multicluster box. Once the fuel cells are activated, they are the primary source of energy for the Phi Suea House loads throughout the time period that the PV system is not producing sufficient amounts of power. Energy from the battery is only required when a sudden high load is needed, for example when an oven or water pump is switched on.

The fuel cells will shut down after the battery voltage rises to 52 V. Normally this will happen when the battery are charged by either the PV system after the sun comes up in the morning, but charging can also occur by the fuel cells themselves if their output exceeds the demand by the Phi Suea House loads during the night. Despite the 52 V electrolyser activation threshold being met, as previously mentioned they will not start while the fuel cell is still running.

To make an initial point on the matter, the energy system was designed in such a way as to minimize the battery use and to keep the DOD (depth of discharge in percent per cycle) to a maximum of 10-15% during normal use. In conjunction with the temperature control of the battery room, it is expected that the batteries lifespan can be increased from 3-5 years to 10-15 years.

Figure 1.3.4 SMA inverters

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1.4 The Hydrogen Room

In the Hydrogen Room, electrical energy from the PV system is used to split water into hydrogen and oxygen through the process of anion exchange membrane (AEM) electrolysis. Hydrogen is an energy carrier and it is stored until the fuel cell accesses it. The fuel cell will convert the hydrogen back into electrical energy to supply the loads at the Phi Suea House during periods when the PV system is not producing any power.

The electrolyser and fuel cells are contained in two "ACTA POWER 1000" boxes. Each box holds two "Heliocentris" electrolysers and one "Heliocentris (Future E)" fuel cell with the two fuel cells each connected to one of two battery banks. The electrolyser system which converts the H2O to H2 and O2 consists of a total of four "ACTA EL500" electrolyser stacks. According to Heliocentris specifications, each stack can produce hydrogen at a rate of 500 Nl/h (normal litres/hour, where "normal" conditions refer to 1 atmosphere and 20⁰C) and at a working pressure of 30 bar. In theory, this rate of hydrogen production should consume 0.4 l/h of water and require 2100 W for operation of an individual stack. Combining the four stacks, 2000 Nl/h of hydrogen should be produced with a power demand of 8400 W. The gas produced has a purity of 99.94%.

Figure 1.4.1 Two Heliocentris Acta Power 1000 boxes

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The hydrogen is stored in three SICC manufactured tanks, each with a capacity of 1000 litres. The tanks are considered to be full when a storage pressure of 30 bar is reached. At normal atmospheric temperature and pressure, this would be the equivalent to 29,607 litres of hydrogen stored in each tank, giving the hydrogen room a total storage capacity of 88,823 litres of gas. With all four electrolysers working continuously, it should take 44.5 hours to fill the three tanks from empty, requiring a total power consumption of 373.8 kWh. This 88,823 litres of hydrogen gas at 30 bar is equivalent to 130 kWh of energy which can be produced in the fuel cells.

As mentioned in the previous section, the fuel cells are activated when the voltage in the battery bank goes below 48.3 V or below 48.8 V over a period of 300 seconds. When working at the same time, the two hydrogen fuel cells can produce a combined 4kW of power. This means that when the storage tanks are full, the fuel cell can continuously supply a 4kW load over a 32.5-hour period before the tanks run out of hydrogen gas. When the PV system is once again supplying power to the micro-grid and charging the batteries with the excess energy produced, the fuel cells will deactivate.

Figure 1.4.2 Hydrogen Room

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1.5 The Battery Room

The final room in the Energy Management Facility is the Battery Room which contains two 2000 Ah battery banks. Each battery bank consists of ten parallel strings made up of four 12 V, 200 Ah lead-acid batteries in series. The four batteries in series raise the battery string to 48 V and the 10 battery strings running in parallel will combine to produce 2000 Ah. 2000Ah at 48 V result in a nominal total of 96 kWh of energy for each battery bank.

Lead-acid batteries are popular because of their high power-to-weight ratio and their low cost and primarily thanks to their use to their use in automobiles, they still hold the largest market share of all energy storage technologies. However, there are several issues commonly associated with lead-acid batteries, namely low energy-to-weight ratio and short lifetime. The lifetime of lead-acid batteries is very strongly affected by the depth of discharge per cycle (DOD, how much the of the battery capacity is discharged and recharged each cycle) and the operating temperatures. With increasing DOD and/or temperatures, the lifetime of the batteries will be shortened almost exponentially.

By using lead-acid batteries in combination with the hydrogen system at the Phi Suea House, the advantages of each technology are maximised and the expected lifespan of the batteries is increased significantly. The batteries supply only short peak loads during the night, making the best use of lead-acid batteries’ strengths. They do a great job at instantaneously supplying high power and do not run for extended periods of time, thus minimizing their DOD and keeping down the operating temperature. The battery storage was sized so that only an estimated 10% to 15% of its charge would be used on a typical day and the Battery Room was designed using techniques to ensure that the ambient temperature remains as low as possible without the need to resort to air-conditioning.

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Figure 1.5.1 Hydrogen load distribution with battery support

Figure 1.5.2 Two 2000Ah 48V battery banks

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2. Introduction to Data

Since the activation of the renewable energy management system, large amounts of data have been collected from four locations: Heliocentris Power Box 15/M, Heliocentris Power Box 16/S, the load distribution box and the SMA Sunny Island Inverters. For the purpose of this report, the primary focus of data analysis will be on the Heliocentris Power Box 15/M and 16/S readings, the data from the other two sources will mainly be used for comparisons and drawing conclusions pertaining to the hydrogen system.

The Heliocentris Power Boxes have been collecting data since 12/02/2015. This will be used to analyse the functionality and efficiency of the hydrogen conversion system whilst also examining Heliocentris support services and the data collection method itself. Data is collected by the Heliocentris boxes from 72 parameters with a timestamp operating at 30 second intervals. This is then transferred online to the Heliocentris server where it is downloaded by logging onto the Phi Suea House user account on the Heliocentris Power plant monitoring web page.

This method of information gathering immediately demonstrates its inefficiencies on initial inspection. In many instances, information has been collected by the Heliocentris Power boxes but, due to connection issues to the Heliocentris server, much of the data has not been sent back to Italy and is consequently not available for download on the server. There is currently no local data management capabilities available in the Heliocentris boxes to save the information on site. This means that for any time that the server in Italy might be down or when there is no connectivity in Chiang Mai, important information relevant to the day to day operation of the hydrogen energy system has been lost. In total, 22% of the period since the initial activation has no related timestamp data, meaning each of the recorded parameters is missing at least 2,496 hours out of a total 11,170 hours of operation. This is due to a combination of the aforementioned inability to connect to the server, periods when the Heliocentris Power is shut down for maintenance and when the Heliocentris Power boxes were not functioning properly due to operational problems.

The Sunny Island inverters have been collecting data since the 27/03/2015 with timestamp intervals of fifteen minutes from over four hundred parameters related to the PV system and the battery banks. This information is easily accessed using the SMA provided software and a direct connection to the inverters.

The Load Distribution box data is collected using Richtmass energy meters and data collection software. This meter and monitoring software is produced by "Sang Chai Meter" in Thailand and is installed on a PC which is connected to the distribution box via

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a RS232 serial communication interface. Since 25/04/2015 readings of the energy loads being supplied to the eleven different delivery points across the site have been taken every 15 minutes. These include the Main house, Guesthouse A, Guesthouse B, the EMF, the four electrolysers in the two Heliocentris Power boxes, the swimming pool, the water tank, the main kitchen, the garden pumps, the workshop and the underground pump room.

2.1 Heliocentris Data

Not all of the data recorded by the Heliocentris server is relevant for this report, so only readings from a total of thirty-five parameters have been downloaded from the server for each Heliocentris box. At the start of the trial period the boxes were labelled AP 15 and AP 16, with each box containing two electrolysers and one fuel cell. The operational conditions programmed into the system originally had each box working almost entirely independently of each other, meaning that the parameters that dictated the electrolyser and fuel cell operational status were not related from one box to the other. The voltage across battery bank A was used to determine if the electrolysers and fuel cells in AP 15 would be running and, independently from this, the voltage across battery bank B was used to control AP 16. The only exception was that the water inlet pressure into the electrolysers was measured by AP 15 and if the pressure was too low, the AP 15 electrolysers would not start and the information would also be sent to the AP 16 electrolysers, not allowing them to start.

When repairs were being carried out on site by a Heliocentris engineer on October 25th 2015, it was decided that an irradiation sensor would be connected to the AP 15 machine. The intention was to create a more reliable condition that would prevent the electrolysers from operating when the suns irradiation was below 250 W/m2. The AP 15 machine would then notify AP 16, that the electrolysers could start producing hydrogen provided its own voltage threshold conditions were met. Now with two parameters from the AP 15 machine controlling electrolyser operations, it was decided on that day to rename them AP M (master) and AP S (slave). Because the two machines worked almost independently from each other for the initial ten months, it is important when referring to the data collected at a specific time that the correct name for each machine is used. This is particularly relevant in the "Operations and Maintenance" section and throughout this paper the Heliocentris boxes will either be called AP 15 and AP 16 when referring to a time before the 25th of October or AP M and AP S if referring to a time after this date. AP 15/M and AP 16/S will be used when referring to the machines in general when no specific time period is involved.

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In the previous section, it was mentioned that at least 22% of all data was missing from the Heliocentris system, for some parameters, as much as 26.95% of data is missing. This was calculated by counting the number of missing thirty second timestamps from the downloaded data. This irregularly missing data coupled with the almost regular operational malfunctions makes it very challenging to produce accurate statistics summarising the Heliocentris boxes' activities, so for the purposes of this report the data will primarily be used to demonstrate operational conditions for the hydrogen system and to highlight the problems that were encountered.

In the data, the AP 15/M EL (electrolyser) and AP 16/S EL power parameter refers to the amount of power used when the electrolysers are producing hydrogen. When a non-zero value is recorded, it signifies that at least one of the two electrolysers were running. Also of note, there is no functional parameter which counted the number of starts and shut downs carried out by each module. There were many instances, as will be shown in chapter 4, when the electrolysers and fuel cells malfunction and don't start or shut down correctly, leading to cycles where the modules continuously restart and shut down. This error may greatly affect the lifespan of these modules but due to a lack of recorded information, no comparisons can be made or conclusions deduced on this matter.

In total AP 15/M electrolysers recorded 8604 hours’ worth of data and were missing 2565 hours, 22.97 % of the total timestamps. Of the 77.03% of the time for which we have readings, hydrogen was being produced, or attempted to be produced by at least one the two electrolysers, 1462.6 hours out of the recorded 8604, 17.7% of the recorded time since activation. A recorded total of 3885 kWh was consumed by the two AP 15 EL modules to produce 1,028,499 litres of hydrogen gas, although once again 24.6% of the hydrogen production readings are missing so this value could be significantly more. These results are greater than what would be expected when comparing with the Heliocentris specifications, 3885 kWh should produce 925,000 litres of hydrogen. It is also worth to note that there is no kind of flow sensor to measure the amount of hydrogen generated - the recorded value of H2 flow is calculated by the machines using a mathematical formula based on the stack voltage and current and assuming normal conditions. Between the 12th of February 2015 and the 22nd of May 2016, 466 days, the AP 15/M electrolyser module 1 was only operational for 256 days while the AP 15/M electrolyser module 2 was fully operational for 306 days, this will be further discussed when analysing the timeline in chapter 3.

The AP 15/M fuel cell power parameter which records the amounts of power being produced by the cell is missing 22.99% of its timestamps, meaning that 8602 hours’ worth of data was recorded while 2567 hours of information is missing. The fuel cell recorded a total energy output of 1350 kWh which was produced over the course of 1022 hours of operation, 11.88% of the total recorded time. Unfortunately, there is no

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measurements taken for the total amounts of hydrogen used, but in theory 922,392 litres of hydrogen is required to produce this much energy. The fuel cell operational status parameter is missing 24.49 % of its information, however, of the 74.51 % which has been recorded, the fuel cell was running for 17.36 % of that time, 1493 hours. This does not correlate with the fuel cell power data which shows that the fuel cell was only operational for 1022 hours and indicates that it may have been active without producing any power for a total period of 471 hours. The fuel cell was fully functioning for 351 days out of 466.

The AP 16/S electrolysers recorded 8654 hours of power consumption but were missing 2501 hours’ worth of data, 22.41% of the information since first activation. At least one of the two electrolysers was operational for a total of 1872 hours, 21.64% of the total recorded time. During this period, they used 6155.7 kWh of energy to produce 1,504,076 litres of hydrogen gas. According to the specifications 6155.7 kWh through the electrolysers should produce 1,465,642 litres of hydrogen. Like with the AP 15/M, this theoretical value is less than what was recorded. The AP 16/S electrolyser module 1 was fully operational for 425 days and AP 16/S electrolyser module 2 was fully operational for 339 out of 466 days.

The AP 16/S fuel cell power parameter is missing 2501 hours, 22.43% of the recorded data. 8652 hours’ worth of timestamps were recorded with energy production occurring during 1279 of those hours, 14.79% of the total time. During these combined periods, the fuel cells produced a total of 1346 kWh of electrical energy which in theory would require 919,659 litres of hydrogen. The fuel cell operational status is missing 23.73% of its values, with 15.84% of the recorded time indicating that the fuel cell was active. This amounts to 1370 hours compared to the 1279 hours that the fuel cell was recorded to actually be producing energy. Although this result is an improvement on the operations of the AP 15/S box, there are still 91 hours that the fuel cell was active but not producing energy. The AP 16/S fuel cell was fully operational for 419 days out of 466.

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2.2 Other Data

A few other interesting points to note about energy management at Phi Suea House; these values were calculated using data from the load distribution box and from the Sunny Island inverters:

The total energy produced by the PV system between 25th of April 2015 and 22nd of May 2016 was 33,493 kWh.

Total energy distributed to the loads across the complex including to the electrolysers between 25th of April 2015 and 22nd of May 2016 is 28,532 kWh.

The total energy distributed to the electrolysers between 25th of April 2015 and 22nd of May 2016 was 10,097 kWh.

The total energy supplied to the Phi Suea House loads during the day time (excluding electrolysers) was 10,030 kWh.

The total energy supplied to the Phi Suea House loads during the night time was 8,773 kWh.

The highest recorded irradiation reading was 1413 W/m2, on the 3rd of November 2015 at 11:30.

Note: Most of the period of data collection falls into the testing period of the Phi Suea House - at this time only a small fraction of the full load was connected to the micro-grid energy system. The full load was only connected for the opening of the full utilisation period on the 29th January 2016.

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3. Operations, Errors and Maintenance

The micro-grid system was initially activated for a ten-month trial period beginning on the 12th of February 2015. The official start of the testing phase was on the 20th March 2015. The Energy Management Facility, Guesthouse A and Guesthouse B were the locations that would receive power from the PV system, the stored hydrogen energy and the battery banks. During this time, the load required to power Phi Suea House would be much lower than the expected final energy demand, meaning that the requirements on the energy storage system would not be very high and that changes could be made to it with minimal costs and losses. The electrical system became fully operational on the 21st of January 2016 with power being supplied to the Main House and the water treatment, collection and distribution system, swimming pool, workshop, pond and garden areas, as well as the areas from the previous testing phase.

An error log has been kept since the beginning of the trial period and a copy of the log notes is available in the online appendix section of this report. This log has been used to create the visual timeline in figure 3.1 which is divided into eight parameters, four for each Heliocentris Power box, covering the entire period of activity. The parameters for the boxes represent the operational status of each fuel cell, each electrolyser (two in each box); and the overall status of the boxes themselves.

Errors recorded into the log are problems that have been initially observed by the on-site engineer when one of the electrolysers or fuel cells was not functioning properly. To solve the problem, the engineer then went to the Heliocentris server and downloaded the machines' error data, decoded the information and troubleshot with the help of Heliocentris engineers. Other than the flashing light that indicates an alarm, there is no function in the system to directly notify the on-site engineer that there has been a particular operational malfunction, a problem is only found when observed or when the data is downloaded and analysed. The error codes recorded during specific times associated with error log entries are listed together in the appendix.

Figure 3.1 is a timeline which has been made from the engineer’s error log and shows the operational status of each module in each Heliocentris box. To quickly explain how to interpret figure 3.1, take for example AP 15 (Heliocentris Power 15/M box) on the 21st of April 2015 when a leak occurred in the box. At this time AP 15 EL MODULE 1 (electrolyser module 1) is no longer running but AP 15 EL MODULE 2 (electrolyser module 2) and the FC (fuel cell) are fully operational. During the period that the operational status remains as stated, electrolyser module 1 is now represented by a red line, electrolyser module 2 and the fuel cell are represented by a green line and the AP 15 overall status is now orange to show that the box is no longer fully functional. In total the timeline covers 481 days with long periods where there is no change in the status of

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any of the parameters. For the purpose of fitting the visualization into this report, breaks in the timeline have been added and signify that the status of the Heliocentris system remains unchanged. The full version of this timeline will be made available in the online appendix.

In addition to the error log kept on site, the errors recorded by the Heliocentris server have also been used to create and explain the timeline. Areas shaded in pink have been highlighted to show periods in which the Heliocentris server was down. Regardless if the system was operational or not at those times, no data could be collected during these timeframes. This is a clear demonstration as to the necessity of having a local data collection system which can be accessed on site.

It must also be noted that, as explained in the "Introduction to Data" section, the Heliocentris Power boxes were initially named "AP15" and "AP16". Following repairs on the 25th October 2015, the boxes were renamed AP M (Master) and AP S (Slave).

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3.1 Analysis of Timeline

The timeline begins on the 12th of February 2015 with the first activation of the system. At this initial stage, the production of hydrogen begins and data starts to be collected from the AP 15 and AP 16 machines while the fuel cells supply power to Guesthouse A, Guesthouse B and the Energy Management Facility when the battery voltage drops below the threshold.

17th March 2015. the first problem occurs 33 days after activation with fuel cell malfunctions in both boxes. It was observed that the fuel cells were not operating and the associated error code intimated that there was an error without being able to directly indicate what the problem was. The system errors were reset/overwritten by uploading new values through a Modbus connection into the firmware of the fuel cell control module, the fuel cells began functioning properly again but only for a short time before they stopped again. This cycle continued for seven days until the 24th of March when the problem was finally discovered. After periods of hydrogen production, the electrolyser would purge and release hydrogen gas at the back of the box. This purged hydrogen gas would rise straight up and into the fuel cell, where it was mistakenly identified as a hydrogen leak, causing the fuel cell to go into error mode. Once discovered, this problem was easily rectified by adding rubber tubing to the hydrogen purge leaving the gas to be released away from the Heliocentris boxes.

27th of March 2015. only three days after the resolution of the first problem, the second complication occurred in AP 15. Neither electrolyser was functioning and the Heliocentris server error code suggested a fan error was at fault and shut down the system. On further inspection, water stains were detected on the AP 15 EL MOD 1 and on the underside of the electronic control module beneath the electrolysers. After opening up the system and checking the electronic module, a connector in AP 15 which is used to distribute power to the mechanisms in the AP 15 box was found to be burnt out, preventing the power supply for the fan in AP 15 MODULE 2, which then recorded the error in the machine. The water stains found on the bottom of the electrolyser, in the electronic module and on the floor of the machine were clear evidence of a leak in the Electrolyser Module 1. Tests were carried out to try and locate the source of the leak but it could not be found. Heliocentris sent out a new connector which was fitted into AP 15 on the 19th of April but on the 21st of April the leak occurred again in AP 15 EL MOD 1. The electrolyser was shut down for further testing leading to the eventual discovery of the leak at the water connector inlet at the bottom of the electrolyser stack. From this point, AP 15 EL MOD 1 was permanently shut down until the cause of the leak could be determined and suitable repairs could be made. This process did not finish until the 25th of October 2015, meaning that the AP 15 box was not fully functional again until approximately seven months after the initial leak.

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14th of May 2015. The monitoring values on the Heliocentris server data interface were incorrect. This was caused by a server problem that was completely unrelated to the daily operation of the system and was quickly resolved by Heliocentris.

21st of May 2015. It was noted in the error log that the fuel cells and electrolysers in both machines were observed to be operating at the same time. On further inspection of the data we see that the problem first occurred on the 19th of May. The error was rectified when Heliocentris performed a remote communication board update. This is a day of particular note which will be further discussed in chapter 4.

10th of June 2015. The Hydrogen flux produced by AP 15 EL MOD 2 was found to be below 500 l/h, the expected production rates. This was the first indication of a fault in the electrolyser stack and on further inspection it can be seen that the continuous decrease in hydrogen production did in fact begin on the 1st of June. The gaps in the bar chart below indicate periods when the electrolyser is not producing hydrogen.

Figure 3.1.1 Rates of hydrogen production per day in AP 15 Electrolyser Module 1

This is typically due to the fact that the pressure in the hydrogen storage tanks remains above 27 Bar, the pressure at which the electrolysers are programmed to restart

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production after entering the "Max Pressure" state. One exception is on the 18th of July, although nothing was observed by the engineer, a voltage stack error was recorded by the machine throughout the course of the day. This error was not observed on the day and seemed to rectify itself the following day. Nonetheless, the AP 15 EL MOD 2 continued to decrease the rate at which it produces hydrogen until the 16th of August, when it is eventually decided to completely shut down the AP 15 machine until maintenance could be carried out by a Heliocentris engineer. It is worth noting that during this period of continued decline, excluding the recorded error code on the 18th of July, the AP 15 machine did not record any errors or alarms that recognised a decrease in hydrogen production.

13th of June 2015. An empty tank warning is observed on AP 16 which caused the machine to be unable to produce hydrogen. There is in fact no malfunction, this error is caused by a server reading error which is resolved by Heliocentris on the 16th of June.

16th of July 2015. The AP 15 fuel cell is found to be operating in maintenance mode. By way of software updates, engineers from Future E tried but failed to repair what was thought to be a fault with the pulse width module regulator in the fuel cell module. It was then agreed to replace the fuel cell. The data shows that the fuel cell malfunction actually began on the 25th of June and the machine continued to try to operate for three weeks before a problem was noticed. An intermittent error code is recorded over the course of this time but no alarms are activated and there is no obvious indication that there has been a fault in the module. From this moment, only AP 15 EL module 2 is still partially operational in the AP 15 box. This will only continue for another month, as previously mentioned, the machine is completely switched off on the 16th of August.

21st of July 2015. AP 16 electrolysers switch themselves into maintenance mode. It is concluded that the communication board has lost the AP 16 IP address. The problem is quickly resolved by resetting the system. Once again, no errors were recorded by the system.

22nd of July 2015. AP 15 appears offline and stops collecting data despite the fact that it is running. Again, the problem seems to resolve itself through a manual system reset.

16th of August 2015 Continued decrease in hydrogen production by AP 15 EL Module 2 leads to full shut down of AP 15 box until repairs are carried out.

22nd of September 2015. A leak of the same nature as the one observed in March is found in the AP 16 box. This is enough evidence to conclude that there is a design flaw with the water inflow connectors for the electrolysers. AP 16 is entirely shut down until repairs can be carried out and the connectors replaced. No errors were recorded by the Heliocentris server to indicate that there had been a leak. At this stage, both AP 15 and

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AP 16 have been shut down and Phi Suea House is operating solely with batteries for energy storage.

25th of October 2015. A Heliocentris engineer comes to Phi Suea House for maintenance on both machines. the machines AP 15 and AP 16 are renamed AP M and AP S respectively:

AP M EL Module 1: Replaced leaking connector. AP M EL Module 2: New electrolyser stack and replaced leaking connector. AP M FC: New Fuel Cell module.

AP S EL Module 1: Discovery of hydrogen leak during repairs to connectors. A

new electrolyser stack would have to be sent out at a later stage. AP S EL Module 2: Replaced leaking connector. AP S FC: No repairs required

Following repairs, AP M is once again fully operational but AP S has only one functioning electrolyser.

2nd of November 2015. A problem occurs with the AP S EL MOD 2 power supply which needs to be replaced. In the meantime, AP S EL MOD 1 is waiting for repairs, so MOD 2 is fitted into the module 1 slot to access its power supply. From this point onwards, all the data recorded from the AP S EL MOD 1 slot will be information to relevant to what was originally the AP 15 EL MOD 2 electrolyser.

16th of January 2016. The electrolyser stack for what was originally AP S EL Module 1 and the power supply for the AP S Module 2 slot are replaced. From this point onwards this electrolyser collects data from module 2.

18th of January 2016. AP S FC is switching to maintenance mode at night. This appears to be a software problem which is rectified with a remote fuel cell update carried out by a Future E engineer on the 22nd of February.

21st of January 2016. The initial testing phase is finished. Over the next several days the Phi Suea House energy system begins to supply load to the Main House, the Workshop, the water tank and treatment system, the garden pump house, the underground waterfall pump house and the swimming pool system.

26th of March 2016. The Heliocentris web server is down and does not come back online until the 19th of April, nearly a month later. Despite the fact that all systems seem to be fully operational during this period, there is no data collected to demonstrate this.

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17th of April 2016. At 10:30, A total load of 34.56 kW is distributed across the Phi Suea House complex. This is the highest recorded load over the duration of the project. Unfortunately, there is no data from the Heliocentris system to analyze for this day.

5th of May 2016. AP S EL MOD 2 stopped functioning due to a stack voltage error and the cause of the fault is unknown. This was the new stack that was replaced on the 18th of January which now needs to be replaced again.

28th of May 2016. The Heliocentris web server is down again and has returned to an online status on the 15th of June.

3.2 Error Codes

Since the activation of the Heliocentris Power boxes, with 24% of the error data missing, 24 different errors occurring a combined total of 3041 times have been collected by the server. Of the 3041 errors, 593 of them can be disregarded as they are not relevant to the data. These are communication errors which have been collected from the empty module 3 and module 4 slots in each box. This still leaves 2448 separate errors which occur for lengths of time that range anywhere between thirty seconds and thirty-five days.

A list of the collected error codes and their meaning are shown in table 3.2.1 below, as well as table 3.2.2 showing the number of times each code was generated from each module in the Heliocentris machines; the two electrolyser modules, the fuel cell module and the electronic control module. To understand each code, after they are downloaded from the server they have to be deciphered using a formula and tables provided by Heliocentris which can be found in the online appendix of this report. In some instances, the same error code can have different meanings which itself depends on the location from which it was detected. For example, error code 512 refers to a fan error when the error is recorded from the AP control, but the same code will mean that there is a refill error if the information is recorded from one of the electrolyser modules.

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2147483648 Communication Loss

2 Refill (recorded from AP control)/, FAN (recorded from EL module)

8192 Stack Voltage

2072 Water level sensor, Pressure sensor, Temperature sensor

2064 Water Level sensor, Tempreature sensor

512 Fan error (recorded from AP control)/ Refill error (recorded from EL module)

2048 Water level sensor, stack voltage

2074 Water level sensor, Refill, Pressure sensor, Temperature sensor

2328 Flow switch, water level sensor, Pressure sensor, Temperature sensor

6152 Water level sensor, pressure sensor, Temperature sensor

8 Water Level sensor and stack voltage

1 Flow switch

65536 FC Unit redundancy, system supplies only part of nominal power

536870912 System operating parameters warning

3 FC unit redundancy; system supplies only part of nominal power, FC rack unit redundancy; fuel cell system not available

536936448 System operating parameters warning, Air supply >45°C

134217728 Hydrogen inlet pressure is low, <7bar

1048576 System fault

402653184 Hydrogen inlet pressure is low, <7bar, Hydrogen inlet pressure is too low, <4bar

33554432 Hydrogen inlet pressure is high, >31bar

34603008 System fault, Hydrogen inlet pressure is high, >31bar

524288 System fault

589824 System operating parameters warning

134283264 System operating parameters warning, Hydrogen inlet pressure is low, <7bar Table 3.2.1 List of error codes and descriptions

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Error Code

AP 15/M Control

AP 15/M EL MOD 1

AP 15/M EL MOD 2

AP 15/M FC

AP 16 / S Control

AP 16/S EL MOD 1

AP 16/S EL MOD 2

AP 16/S FC

TOTAL

2147483648 128 126 125 51 175 173 171 74 1616

2 2 8 8 0 0 0 0 0 18

8192 76 0 0 0 8 0 0 0 84

2072 14 0 0 0 5 0 0 0 19

2064 2 0 0 0 0 0 0 0 2

512 8 2 2 0 0 3 4 0 19

2048 2 0 0 10 0 0 0 0 12

2074 0 0 0 0 2 0 0 0 2

2328 0 0 0 0 2 0 0 0 2

6152 0 61 14 0 0 63 21 0 159

8 0 16 4 0 0 11 10 0 41

1 0 1 1 0 0 4 2 0 8

65536 0 0 0 249 0 0 0 540 789

536870912 0 0 0 35 0 0 0 23 58

3 0 0 0 60 0 0 0 67 127

536936448 0 0 0 1 0 0 0 0 1

134217728 0 0 0 14 0 0 0 24 38

1048576 0 0 0 1 0 0 0 0 1

402653184 0 0 0 4 0 0 0 11 15

33554432 0 0 0 16 0 0 0 0 16

34603008 0 0 0 1 0 0 0 0 1

524288 0 0 0 0 0 0 0 5 5

589824 0 0 0 0 0 0 0 2 2

134283264 0 0 0 0 0 0 0 6 6

Total 232 214 154 442 192 254 208 752 2448 Table 3.2.2 Count of errors per module

From table 3.2.2 above it is clear to see that the most common error occurs 1616 times, two thirds of the total collected. In fact, this error is the same one that we have disregarded earlier from our total due to its presence in the absent 3 and 4 modules of each box. The code refers to a communication error within the machine itself, as opposed to communication with the Heliocentris server. 1031 of these particular recorded errors, amount to the number of incidents where the problem lasted for under a minute. These numbers may be relevant for data analysis over a longer period of time, but for the day to day operations and maintenance of the machines, these errors are impractical to review and cryptic to understand.

There seems to be little in common between the errors recorded into the log by the engineer at a given time and the errors recorded by the machine at the same time. Take the 27th of March 2015 as one of the more obvious examples from the timeline, error

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code 512 was recorded from the AP 15 control and error code 2 was recorded in both AP 15 EL module 1 and module 2. Both of these codes indicate a fan error in the AP control and EL module respectively. When the machine was inspected, there was indeed an error with the fan which was no longer functioning due to a lack of power but this was not what caused the problem. The only reason that the leak was discovered was thanks to the physical evidence in the form of water stains which revealed that there had been one. There were no other error codes during this period that related to the leak and it may have taken much longer to discover had it not been for the marks left behind.

Take as another example the 16th of July 2015, AP 15 FC is found to be switching to maintenance mode at night. Error code 3 (FC unit redundancy; system supplies only part of nominal power, FC rack unit redundancy; fuel cell system not available) is recorded in the fuel cell module for a period of two minutes when the fuel cell is supposed to be running. Other than the physical observation that the fuel cell is not functioning properly, this is the only indication that there might be a problem. In this case, the fuel cell needed to be replaced with very little warning from the software. This is far from ideal for hardware that is expected to be able to run autonomously.

Between the 12th of January 2015 and the 22nd of May 2016, the total relevant error count was 3041 with 1576 of these occurring for less than 60 seconds. This does not include the 24% of the time, where information was not collected due to connection problems with the server. Of the 24 different error codes collected, only 9 of them were found to be potentially relevant when comparing the error log with the error codes recorded at similar times. For the purposes of this report, it has not been deemed necessary to research these other 14 errors further but it is worth noting that they have been collected with no clear understanding of their significance.

The method in which these error codes are collected, displayed and correlated with live operations, is not practical for a local engineer to manage this system. There are many areas of improvement required to facilitate enhanced surveillance and maintenance of the Heliocentris Power boxes, namely having a local server collecting the error data, a simpler software interface to understand the codes and what warnings and errors they are referring to, an automatic warning system to send out an email when an error or a deviation from normal operation is recorded. From the experiences gained at the Phi Suea House project, a more robust communication system to reduce internal communication issues and some additional monitoring parameters, for example water leak detection, might be added to the system.

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4. Examples and Analysis of System Energy Management

Throughout the course of the sixteen months that Phi Suea House has been producing and managing its own energy, the micro-grid system has experienced a variety of conditions. These have led to periods were the system performed as programmed, but also to other times when flaws where discovered and modifications needed to be made to remove inconsistencies. The following section will focus on a few of these specific days demonstrating how the system works while also highlighting some problems that were faced and the solutions that were used to improve efficiency.

4.1 Energy Production and Management 28th April 2015

The graph below in figure 4.1.1 represents a typical day during the testing period when the load was relatively small due to the fact that power was only being supplied to Guesthouse A, Guesthouse B and the Energy Management Facility.

Figure 4.1.1 Energy production and management 28/04/2015

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28/04/2015 00:00 28/04/2015 07:12 28/04/2015 14:24 28/04/2015 21:36 29/04/2015 04:48

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Total LoadkW

ElectrolyzerLoad kW

Fuel Cell Power kW

Storage Inverter Power kW Battery Charging + Total Load kW Irradiation W/m2

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With irradiation levels exceeding 1000 W/m2 in the middle of the day and only two brief periods of cloud cover at 12:15 and 14:15, this was a good day for energy production. However, this was not a particularly good day for hydrogen system operations.

Figure 4.1.2 is a scaled up visual representation of figure 4.1.1, with areas that represent periods of the day coloured in to show which part of the energy management system is supplying loads at which time.

Figure 4.1.2 Energy production and load distribution 28/04/2015

At 00:00, the total Phi Suea House load is provided by the battery banks until 00:38, the area in blue. The data shows that at 00:38 the AP 15 fuel cell tried to activate five times before it managed to finally run successfully throughout the night from 2:13 until 6:35, it is not known why the fuel cell struggled to start. On this day, the conditions were set so that if the battery voltage was to decrease below the 49 V higher threshold for a period of 300 seconds or if the battery voltage decreased to below the 48.5 V lower threshold at any stage, the fuel cell should be activated. Neither of these conditions were met but the fuel cell in AP 15 still started itself which could be due to an internal communication

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issue. The fuel cell shut down as expected at 06:32 when the battery voltage increased to above 52.5 V. The fuel cell in AP 16 did not operate at all throughout the night. An error code suggesting that the hydrogen inlet pressure was below 4 Bar prohibited it from starting. There are 2 error codes that are associated with the decreasing pressure in the hydrogen tanks, the first is top warn that the pressure is below 7 Bar, the second code is to warn that the pressure is below 4 Bar. Because of slight calibration differences between the two Heliocentris machines, there is a 0.3 bar difference in the pressure values recorded by each box. Both AP 15 and AP 16 recorded the error "Hydrogen inlet pressure is low, <7bar" but readings for the pressure by AP 16 decreased to 3.89 Bar, while the readings for the pressure by AP 15 only went as low as 4.15 Bar. This caused AP 16 to go into a different error mode "Hydrogen inlet pressure is low, <7bar, Hydrogen inlet pressure is too low, <4bar". When the pressure increased back to 8 Bar at 16:00 of the 27th April, AP 15 error message disappeared and proceeded to work as expected, while with AP 16 the error remained in the system until 10:58 on the 28th prohibiting the fuel cell from starting until later that evening. During the early morning period of the 28th of April, while one fuel cell was operating the pressure in the tank decreased from 8.71 Bar to 7.35 Bar, this 1.36 Bar pressure difference describes the quantity of hydrogen that has been used throughout the night and is equivalent to 4030 litres of hydrogen gas. After the sun rises, the site load is fully supplied by the PV system from 06:45 until 18:00. The load in the morning before 10:15 remains relatively low, with a small peak of 2.39 kW reached at 9:00 o'clock. The excess energy produced is used to charge the batteries, with the peak power produced during this period reaching as high as 6.39 kW which occurred at 8:00.

At this stage in the project, different conditions are being used to activate the electrolysers in the two AP boxes. AP 16 is programmed to stop after the voltage in the battery bank drops below the 51 V threshold and there is no automatic restart function; the electrolysers can only be switched on manually which the on-site engineer does at 10:15. AP 15 is set to begin hydrogen production five hours after the fuel cell is shut down.

At 10:15, with the activation of the electrolysers the load immediately increases by 4 kW, which is easily seen as "electrolyser load" in figure 4.1.2. The graph also shows that there is another increase of 2 kW to the electrolyser load at midday. From the "Errors and Maintenance" chapter we know that at this time the AP 15 box only has one functional electrolyser due to a leak. This explains why there was only an increase of 2kW instead of 4 kW to the electrolyser load when this machine finally switched on.

From midday until 18:00 the system operates as expected, the PV system supplies energy to the three buildings, to the electrolysers for hydrogen production and to the

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batteries for charging. During the period that the three electrolysers are functioning the pressure in the hydrogen tanks increases from 7.35 Bar to 11.25 bar.

The two electrolysers in AP 16 shut down at 17:15 after the battery cluster 2 voltage decreases below the "low battery state" threshold of 51 V. The electrolyser in AP 15 shut down at 17:40, as soon as the fuel cell in AP 15 is activated. This fuel cell was programmed to start after the battery voltage went below 49 V for a continuous 300 seconds. The fuel cell in AP 16 was also programmed to start under the same conditions which occurred at the same time, 17:40.

Coincidentally, there was a large load increase around the same time that the electrolyser modules shut down, the PV system stopped producing energy and the fuel cells are activated. This is most likely due to air conditioning units being activated after the tenants in the guesthouses returned home for the day. The batteries help the fuel cells cover the large peaks of this load until 20:15 when it decreases to about 3 kW. The fuel cells continue to supply all of the required load until the early hours of the morning of the 29th of April where there are a few battery supported load peaks, which once again are presumably caused by air conditioning compressors switching on and off.

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4.2 Malfunctioning System 21st of May and 27th of May 2015

After the first four months of the testing phase, changes to remove inefficiencies were made in the design of the control mechanism used to activate the fuel cells and electrolysers. On the 14th of May, the conditions previously described from the 28th of April were modified. Both fuels cells were now set to activate when the battery voltage decreases to below 48.5 V for a continuous period of 300 seconds or if at any stage the battery voltage went below 48 V. The fuel cells remained programmed to shut themselves down once the battery voltage increased to above 52.5 V. The electrolysers in both boxes were programmed to enter a low battery alarm state in which it stops producing hydrogen after the battery voltage decreased to below 50 V and to exit this alarm state after the battery voltage increased to 52 V. Even after these conditions were met, the electrolysers were still programmed not to start until four hours after the fuel cells shut down.

21st of May 2015

The 21st of May was recorded in the error log because the electrolysers and fuel cells were found to be operating at the same time. This is a good example that demonstrates how the automated PV, hydrogen and battery system are supposed to function with each other, while it is also useful to show what happens when a fault occurs. At the time, AP 15 EL MOD 1 was still offline due to a leak but the three other electrolysers and the two fuel cells were fully functional. The two figures 4.2.1 and 4.2.2 represent AP 16 and AP 15 respectively, they show the power produced by the fuel cells and used by the electrolysers on the primary y-axis. The fuel cell voltage which corresponds to the battery voltage and the various thresholds that are used as conditions to activate and shut down each mechanism are on the secondary y-axis.

Figure 4.2.1 shows that AP 16 FC started producing power at 03:06 after the fuel cell voltage decreased to below 48.5 V for a period of 300 seconds. However, on closer inspection of the data in table 4.2.1, the fuel cell actually began operating at 02:39 after five minutes of continuous voltage below 48.5 V, but did not produce any power and subsequently shut down at 02:51, demonstrating a fault in the control of the system. Table 4.2.2 shows that the system was finally activated again at 03:03 and eventually began producing power at 03:06. In the status column of these tables, the number 1 represents that the fuel cell has been activated and a 0 signifies that it is inactive.

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Figure 4.2.1 AP 16 Electrolyser and fuel cell operations 21/05/2015

Time Power W Status Voltage

Time Power W Status Voltage

21/05/2015 02:34:30 0 0 48.457001

21/05/2015 02:39:00 0 0 48.416

21/05/2015 02:35:00 0 0 48.457001

21/05/2015 02:39:30 0 1 48.416

21/05/2015 02:35:30 0 0 48.389

21/05/2015 02:40:00 0 1 48.688

21/05/2015 02:36:00 0 0 48.416

21/05/2015 02:40:30 0 1 48.646999

21/05/2015 02:36:30 0 0 48.457001

21/05/2015 02:41:00 0 1 48.619999

21/05/2015 02:37:00 0 0 48.416

21/05/2015 02:41:30 0 1 48.646999

21/05/2015 02:37:30 0 0 48.457001

21/05/2015 02:42:00 0 1 48.578999

21/05/2015 02:38:00 0 0 48.457001

21/05/2015 02:42:30 0 1 48.646999

21/05/2015 02:38:30 0 0 48.457001

21/05/2015 02:43:00 0 1 48.578999

Table 4.2.1 AP 16 Fuel Cell not producing power after start, 21/05/2015.

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21/05 00:00 21/05 04:48 21/05 09:36 21/05 14:24 21/05 19:12 22/05 00:00

VkW

Time

EL 16 power [kW] FC 16/S Power [kW] FC 16/SVoltage

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Table 4.2.2 AP 16 Fuel Cell starts, 21/05/2015.

The fuel cell is programmed to shut down after the voltage crosses the 52.5 V threshold, but instead remains active, which can be clearly seen on the graph as the voltage line crosses the threshold. The data for this point in time is also represented in table 4.2.3.

Time Power W Status Voltage

Time Power W Status Voltage 21/05/2015 07:12:00 1191.4823 1 52.442001

21/05/2015 07:15:00 1552.69507 1 52.741001

21/05/2015 07:12:30 1141.13794 1 52.442001

21/05/2015 07:15:30 1535.81787 1 52.741001

21/05/2015 07:13:00 1192.0957 1 52.469002

21/05/2015 07:16:00 1556.28674 1 52.862999

21/05/2015 07:13:30 1192.0957 1 52.469002

21/05/2015 07:16:30 1402.60706 1 52.808998

21/05/2015 07:14:00 1193.02722 1 52.509998

21/05/2015 07:17:00 1607.03516 1 52.862999

21/05/2015 07:14:30 1192.0957 1 52.469002

21/05/2015 07:17:30 1487.86182 1 52.835999

Table 4.2.3 AP 16 Fuel cell not shutting down after exceeding 52.5 V threshold, 21/05/2015

Time Power W Status Voltage

Time Power W Status Voltage 21/05/2015 02:57:30 0 0 48.619999

21/05/2015 03:03:30 0 1 48.619999

21/05/2015 02:58:00 0 0 48.457001

21/05/2015 03:04:00 0 1 48.320999

21/05/2015 02:58:30 0 0 48.389

21/05/2015 03:04:30 0 1 48.578999

21/05/2015 02:59:00 0 0 48.416

21/05/2015 03:05:00 0 1 48.320999

21/05/2015 02:59:30 0 0 48.416

21/05/2015 03:05:30 0 1 48.578999

21/05/2015 03:00:00 0 0 48.416

21/05/2015 03:06:00 0 1 48.348

21/05/2015 03:00:30 0 0 48.389

21/05/2015 03:06:30 1120.41406 1 49.313999

21/05/2015 03:01:00 0 0 48.389

21/05/2015 03:07:00 1915.58398 1 49.884998

21/05/2015 03:01:30 0 0 48.348

21/05/2015 03:07:30 1869.71619 1 49.938999

21/05/2015 03:02:00 0 0 48.348

21/05/2015 03:08:00 2004.64002 1 50.116001

21/05/2015 03:02:30 0 0 48.348

21/05/2015 03:08:30 1824.25537 1 50.007

21/05/2015 03:03:00 0 1 48.320999

21/05/2015 03:09:00 1761.68958 1 50.048

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The fuel cell remains active until 10:55. At this point we have the four-hour timer, although it remains unknown as to why it shut down. In the voltage column of table 4.2.4, data was not collected by the AP 16 machine at the time it switched itself off which may be an indication of the problem.

Time Power W Status Voltage

Time Power W Status Voltage 21/05/2015 10:53:30 927.34845 1 53.666

21/05/2015 10:55:30 0 0

21/05/2015 10:54:00 926.864624 1 53.638

21/05/2015 10:56:00 0 0 53.067001

21/05/2015 10:54:30 926.864624 1 53.638

21/05/2015 10:56:30 0 0 53.094002

21/05/2015 10:55:00 926.173462 1 53.598

21/05/2015 10:57:00 0 0 53.094002

Table 4.2.4 AP 16 Fuel cell shutting down for unknown reason, 21/05/2015.

Both electrolysers start operating at 11:28 as seen in table 4.2.5, after having been manually activated by the on-site engineer. They could not start automatically due to the four-hour timer which would have prevented activation until 14:55.

Time Power W Voltage

Time Power W Voltage 21/05/2015 11:26:00 0 53.040001

21/05/2015 11:28:30 4451.5068 53.366001

21/05/2015 11:26:30 0 52.903999

21/05/2015 11:29:00 4395.8823 53.067001

21/05/2015 11:27:00 0 53.067001

21/05/2015 11:29:30 4349.2012 52.999001

21/05/2015 11:27:30 0 52.903999

21/05/2015 11:30:00 4312.1099 52.931

21/05/2015 11:28:00 371.35236 53.040001

21/05/2015 11:30:30 4283.2583 52.999001

Table 4.2.5 AP 16 Electrolyser Starts, 21/05/2015.

42

43

The AP 16 electrolysers shut down at 15:40, restart at 15:55, shut down again at 16:00 and restart again at 16:04. It is not understood why this has happened as none of the conditions were met that would instruct the AP 16 to behave this way.

Time Power W Voltage

Time Power W Voltage

21/05/2015 15:37:30 4145.6045 52.808998

//////////////////////////////////////////////////////////

21/05/2015 15:38:00 4144.626 52.835999

21/05/2015 15:58:30 4179.9575 52.972

21/05/2015 15:38:30 4145.1152 52.931

21/05/2015 15:59:00 4172.3164 53.040001

21/05/2015 15:39:00 4143.4507 52.835999

21/05/2015 15:59:30 1136.2942 53.040001

21/05/2015 15:39:30 4143.7432 52.999001

21/05/2015 16:00:00 0 53.067001

21/05/2015 15:40:00 0 52.673

21/05/2015 16:00:30 0 52.999001

21/05/2015 15:40:30 0 52.999001

/////////////////////////////////////////////////////////

21/05/2015 15:41:00 0 53.040001

21/05/2015 16:03:00 0 53.067001

/////////////////////////////////////////////////////////

21/05/2015 16:03:30 0 52.903999

21/05/2015 15:53:00 0 52.999001

21/05/2015 16:04:00 2685.532 53.23

21/05/2015 15:53:30 0 53.067001

21/05/2015 16:04:30 4340.6885 51.775002

21/05/2015 15:54:00 0 52.999001

21/05/2015 16:05:00 4272.1284 51.639

21/05/2015 15:54:30 0 52.931

21/05/2015 16:05:30 4233.46 51.612

21/05/2015 15:55:00 525.20258 52.931

21/05/2015 16:06:00 4210.3022 51.313

21/05/2015 15:55:30 4405.958 53.134998

21/05/2015 16:06:30 4194.0469 51.203999

21/05/2015 15:56:00 4317.9224 53.040001

21/05/2015 16:07:00 4182.4238 51.014

Table 4.2.6 AP 16 Electrolyser shuts down and restarts several times for unknown reasons, 21/05/2015.

The AP 16 EL shuts down for the day at 18:07, but not before shutting down and reactivating on several occasions. For the second shut down event at 17:59:30 in the table 4.2.7 below, the voltage goes below the 50 V "low battery alarm state" threshold and should deactivate. For the other two shut down events at 17:53:30 and 18:07:00, it is conceivable that the battery voltage went below 50 V during the 30 second period between readings as the previous voltage values are close to this threshold and seem to be decreasing, although this cannot be known for certain. The two electrolyser re-starts at 17:57:30 and 18:05:30 seem to indicate a similar issue, leading up to these exact times, the voltage is continuously increasing and in both instances rises to 51.911 V in the 30 second period before activation with 52 V being the restart threshold. Once again, it is possible that the rise above the 52 V threshold happened between measurements right before the voltage dropped again.

43

44

Time Power W Voltage

Time Power W Voltage 21/05/2015 17:51:30 4202.4126 50.075001

21/05/2015 18:00:00 0 51.041

21/05/2015 17:52:00 4192.4004 50.116001

21/05/2015 18:00:30 0 51.313

21/05/2015 17:52:30 4185.4468 50.075001

21/05/2015 18:01:00 0 51.502998

21/05/2015 17:53:00 4181.3613 50.183998

21/05/2015 18:01:30 0 51.612

21/05/2015 17:53:30 4176.9517 50.048

21/05/2015 18:02:00 0 51.639

21/05/2015 17:54:00 0 51.041

21/05/2015 18:02:30 0 51.775002

21/05/2015 17:54:30 0 51.476002

21/05/2015 18:03:00 0 51.842999

21/05/2015 17:55:00 0 51.707001

21/05/2015 18:03:30 0 51.869999

21/05/2015 17:55:30 0 51.910999

21/05/2015 18:04:00 0 51.910999

21/05/2015 17:56:00 0 52.006001

21/05/2015 18:04:30 0 51.966

21/05/2015 17:56:30 0 51.910999

21/05/2015 18:05:00 0 51.910999

21/05/2015 17:57:00 4352.4341 51.367001

21/05/2015 18:05:30 900.55371 51.666

21/05/2015 17:57:30 4309.7661 50.483002

21/05/2015 18:06:00 4388.665 50.509998

21/05/2015 17:58:00 4257.5527 50.183998

21/05/2015 18:06:30 4306.5459 50.116001

21/05/2015 17:58:30 4228.0752 50.143002

21/05/2015 18:07:00 4264.2207 50.116001

21/05/2015 17:59:00 4210.6216 50.116001

21/05/2015 18:07:30 0 50.007

21/05/2015 17:59:30 4196.0972 49.911999

21/05/2015 18:08:00 0 51.082001

Table 4.2.7 AP 16 Electrolyser shuts down after several restarts 21/05/2015

The inconsistencies in both the AP 16 Fuel Cell and electrolyser for this day indicate that the problem seems to lie in the control programming or internal communication system.

The 21st of May was no better for AP 15. Figure 4.2.2 below shows activities for the AP 15 fuel cells for this day. There is no accurate data for the power used by the electrolyser, the readings taken by the AP 15 machine have been wildly inaccurate and examples of these are shown in Table 4.2.8 in the "AP 15 EL" column. The inaccuracy is known, because the total electrolyser load for the two AP boxes is recorded in the load distribution data. When the Heliocentris data for electrolyser power from the two machines is added together, their sum is a long way from matching the recorded electrolyser load values and it can be concluded that despite the error in the readings, AP 15 EL module 2 is still functioning as normal. The hydrogen flux produced from the electrolyser was recorded correctly and will be used instead to compare with the fuel cell voltages to check if operational conditions were being followed by the machine.

44

45

Time

Electrolyser Total load Readings from distribution box AP15 + AP 16 (kW)

AP 15 EL (kW)

AP16 EL (kW)

21/05/2015 10:15 0 0 0

21/05/2015 10:30 0 0 0

21/05/2015 10:45 0 0 0

21/05/2015 11:00 0.653041 0.004596 0

21/05/2015 11:15 1.993521 0.004852 0

21/05/2015 11:30 1.956561 0.004852 4312.1099

21/05/2015 11:45 5.891337 0.004852 4099.9585

21/05/2015 12:00 5.99454 0.004852 4106.1084

Table 4.2.8 Incorrect AP 15 EL Power readings

Figure 4.2.2 AP 15 Fuel cell operations (AP 15 EL power data recording error) 21/05/2015

40

42

44

46

48

50

52

54

56

58

60

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

42145 42145.2 42145.4 42145.6 42145.8 42146

V

kW

Time

EL 15 power [kW] FC 15/M Power [kW] FC 15/MVoltage

45

46

It can immediately be seen that the fuel cell had trouble activating on this day and the data recorded in table 4.2.9 doesn't make much sense. The fuel cell status suggests that the machine is consistently operating but not producing power in any recognizable and worthwhile way. The hydrogen tanks also remain at a regular pressure, more evidence that the fuel cell is not functioning properly.

Time Power W Status Voltage Cylinder pressure Bar

21/05/2015 00:01:30 0 1 48.918999 17.717285

21/05/2015 00:02:00 0 1 48.918999 17.717285

21/05/2015 00:02:30 0 1 48.918999 17.717285

21/05/2015 00:03:00 0 1 48.457001 17.717285

21/05/2015 00:03:30 0 1 48.945999 17.709961

21/05/2015 00:04:00 0 1 48.918999 17.717285

21/05/2015 00:04:30 0 1 48.918999 17.717285

21/05/2015 00:05:00 0 1 48.918999 17.717285

21/05/2015 00:05:30 797.688965 1 48.877998 17.709961

21/05/2015 00:06:00 0 1 48.851002 17.709961

21/05/2015 00:06:30 0 1 48.416 17.717285

21/05/2015 00:07:00 0 1 48.851002 17.717285

21/05/2015 00:07:30 0 1 48.877998 17.717285

21/05/2015 00:08:00 0

48.810001 17.717285

21/05/2015 00:08:30 0 1 48.810001 17.717285

21/05/2015 00:09:00 109.334396 1 48.810001 17.709961

21/05/2015 00:09:30 0 1 48.756001 17.717285

21/05/2015 00:10:00 0 1 48.756001 17.717285

21/05/2015 00:10:30 0 1 48.279999 17.717285

21/05/2015 00:11:00 0 1 48.212002 17.702148

21/05/2015 00:11:30 109.061119 1 48.688 17.717285

21/05/2015 00:12:00 108.969276 1 48.646999 17.709961

21/05/2015 00:12:30 108.908798 1 48.619999 17.709961

21/05/2015 00:13:00 0 1 48.117001 17.709961

21/05/2015 00:13:30 0 1 48.158001 17.717285

21/05/2015 00:14:00 0 1 48.619999 17.709961 Table 4.2.9 Fuel cell does not produce power when active, 21/05/2015.

The fuel cell continues like this throughout the course of the night with the status occasionally changing from active to inactive and back again, until at 04:32 for no obvious reason it begins to function as it should. Table 4.2.10 shows the fuel cell starting without having met any of its thresholds of 48.5 V for 300 seconds or 48 V.

46

47

Time Power W Status Voltage

Time Power W Status Voltage

21/05/2015 04:30:00 0 0 48.457001

21/05/2015 04:36:00 0 1 48.810001

21/05/2015 04:30:30 0 0 48.348

21/05/2015 04:36:30 0 1 48.756001

21/05/2015 04:31:00 0 0 48.279999

21/05/2015 04:37:00 0 1 48.646999

21/05/2015 04:31:30 0 0 48.279999

21/05/2015 04:37:30 0 1 48.578999

21/05/2015 04:32:00 0 0 48.252998

21/05/2015 04:38:00 1037.20325 1 49.110001

21/05/2015 04:32:30 0 1 48.783001

21/05/2015 04:38:30 1358.99268 1 49.382

21/05/2015 04:33:00 0 1 48.810001

21/05/2015 04:39:00 1914.00964 1 49.844002

21/05/2015 04:33:30 0 1 48.783001

21/05/2015 04:39:30 1787.87842 1 49.884998

21/05/2015 04:34:00 0 1 48.810001

21/05/2015 04:40:00 1878.88892 1 50.183998

21/05/2015 04:34:30 0 1 48.783001

21/05/2015 04:40:30 1799.56226 1 50.210999

21/05/2015 04:35:00 0 1 48.783001

21/05/2015 04:41:00 1938.54724 1 50.483002

21/05/2015 04:35:30 0 1 48.783001

21/05/2015 04:41:30 1743.27551 1 50.442001

Table 4.2.10 AP 15 Fuel cell starts producing power, 21/05/2015.

The AP 15 fuel cell shuts down at 07:12:30, two minutes after it was supposed to shut down following the voltage increase above the 52.5 V threshold, there is no explanation for this delay.

Time Power W Status Voltage

Time Power W Status Voltage

21/05/2015 07:08:30 1257.62402 1 52.401001

21/05/2015 07:12:30 0 1 51.666

21/05/2015 07:09:00 1258.60803 1 52.442001

21/05/2015 07:13:00 0 1 51.612

21/05/2015 07:09:30 1259.25598 1 52.469002

21/05/2015 07:13:30 0 1 51.570999

21/05/2015 07:10:00 1260.23999 1 52.509998

21/05/2015 07:14:00 0 1 51.570999

21/05/2015 07:10:30 1260.23999 1 52.509998

21/05/2015 07:14:30 0 0 51.136002

21/05/2015 07:11:00 1261.53601 1 52.563999

21/05/2015 07:15:00 0 0 51.136002

21/05/2015 07:11:30 1227.89502 1 52.563999

21/05/2015 07:15:30 0 0 51.136002

21/05/2015 07:12:00 1229.48352 1 52.632

21/05/2015 07:16:00 0 0 51.176998

Table 4.2.11 AP 15 Fuel Cell shuts down, 21/05/2015.

47

48

The unusual fuel cell behaviour continues throughout the day, producing small amounts of power despite the status being off and none of the activation conditions being met. As is suggested with the AP 16 machine, the problem is most likely caused by firmware communication errors and is demonstrated in the data from table 4.2.12.

Time Power W Status Voltage

Time Power W Status Voltage

21/05/2015 11:59:00 0 0 52.999001

21/05/2015 12:03:00 0 0 52.903999

21/05/2015 11:59:30 0 0 52.903999

21/05/2015 12:03:30 0 0 52.903999

21/05/2015 12:00:00 0 0 52.999001

21/05/2015 12:04:00 0 0 52.903999

21/05/2015 12:00:30 0 0 52.768002

21/05/2015 12:04:30 116.950401 0 52.903999

21/05/2015 12:01:00 0 0 52.972

21/05/2015 12:05:00 116.950401 0 52.768002

21/05/2015 12:01:30 117.013123 0 52.972

21/05/2015 12:05:30 117.013123 0 52.700001

21/05/2015 12:02:00 0 0 52.808998

21/05/2015 12:06:00 116.79808 0 52.741001

21/05/2015 12:02:30 0 0 52.862999

21/05/2015 12:06:30 0 0 52.673

Table 4.2.12 Fuel cell showing unusual behaviour, 21/05/2015

Table 4.2.13 shows that hydrogen production started at 10:54. There is no clear indication as to why this started, the fuel cell had not yet been shut down for four hours and the voltage had remained above 52 V since the fuel cell shut down - the likely explanation is that the electrolysers were started manually.

Time H2 Flux Nl/h Voltage

Time

H2 Flux Nl/h Voltage

21/05/2015 10:51:00 0 52.237999

21/05/2015 10:54:00 31.148083 52.141998

21/05/2015 10:51:30 0 52.237999

21/05/2015 10:54:30 70.333481 52.169998

21/05/2015 10:52:00 0 52.237999

21/05/2015 10:55:00 203.42647 52.141998

21/05/2015 10:52:30 0 52.209999

21/05/2015 10:55:30 448.78806 52.141998

21/05/2015 10:53:00 0 52.169998

21/05/2015 10:56:00 464.63684 52.169998

21/05/2015 10:53:30 0 52.169998

21/05/2015 10:56:30 473.81268 52.209999 Table 4.2.13 AP 15 Electrolyser starts, 21/05/2015.

48

49

The problems for the electrolyser operations continued throughout the afternoon with the machine inexplicably stopping and starting on four occasions. Table 4.2.14 highlights a few of these and also shows that the fuel cell seemed to be attempting to make a start at the same time as the electrolyser produced hydrogen.

Time H2 Flux Nl/h Voltage

FC Power W

Time H2 Flux Nl/h Voltage

FC Power W

21/05/2015 13:23:00 489.945526 50.075 0

21/05/2015 15:23:30 496.343719 52.142 0

21/05/2015 13:23:30 490.504303 50.007 0

//////////////////////////////////////////////////////////////////////

21/05/2015 13:24:00 489.945526 50.007 112.015678

21/05/2015 16:03:30 526.641968 52.102 0

21/05/2015 13:24:30 0 50.483 0

21/05/2015 16:04:00 527.193787 52.51 117.622398

21/05/2015 13:25:00 0 50.483 0

21/05/2015 16:04:30 527.193787 50.946 0

///////////////////////////////////////////////////////////////////

21/05/2015 16:05:00 526.364868 50.946 0

21/05/2015 15:20:30 0 52.238 117.013123

21/05/2015 16:05:30 0 50.973 0

21/05/2015 15:21:00 0 52.21 0

21/05/2015 16:06:00 0 50.578 113.294724

21/05/2015 15:21:30 0 52.142 0

21/05/2015 16:06:30

50.238 0

21/05/2015 15:22:00 23.094471 52.142 0

21/05/2015 16:07:00

50.184 0

21/05/2015 15:22:30 70.615204 52.17 0

21/05/2015 16:07:30 0 50.007 0

21/05/2015 15:23:00 219.007492 52.17 116.860802

21/05/2015 16:08:00 0 49.776 0

Table 4.2.14 AP 15 Fuel cell and electrolyser trying to operate simultaneously, 21/05/2015

27th of May 2015

After the problems described above were discovered, on the 26th of May Heliocentris software engineers remotely repaired a communication malfunction within the boxes. To compare the systems functionality before and after this problem was discovered, the 27th of May is examined below. The AP 15 fuel cell activation threshold is changed to match the AP 16 thresholds at 8:20 with the higher threshold changed to 49 V for 300 seconds and the lower threshold changed to 48.5 V.

Figure 4.2.3 clearly shows that the fuel cell and electrolysers only activate once during the day, and not at the same time. Unfortunately, this is not evidence that the AP 16 box is operating correctly under the programmed conditions. At 00:59 the system state activates and is recorded as running but without producing power until 01:51. Sample data from this period is shown in table 4.2.15. In table 4.2.16, the fuel cell starts six minutes after the higher threshold was reached which would seem correct.

49

50

Figure 4.2.3 AP 16 Fuel cell and electrolyser operations. 27/05/2015

Time Power W Status Voltage

Time Power W Status Voltage

27/05/2015 01:41:30 0 1 49.150002

27/05/2015 01:44:00 0 1 49.150002

27/05/2015 01:42:00 0 1 49.110001

27/05/2015 01:44:30 204.46401 1 49.150002

27/05/2015 01:42:30 0 1 49.110001

27/05/2015 01:45:00 0 1 49.110001

27/05/2015 01:43:00 424.656 1 49.150002

27/05/2015 01:45:30 0 1 49.110001

27/05/2015 01:43:30 0 1 49.150002

27/05/2015 01:46:00 0 1 49.110001 Table 4.2.15 Fuel cell status as operational but not producing power, 27/05/2015.

40

42

44

46

48

50

52

54

56

58

60

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

12:00:00 AM 3:00:00 AM 6:00:00 AM 9:00:00 AM 12:00:00 PM 3:00:00 PM 6:00:00 PM 9:00:00 PM 12:00:00 AM

VkW

Time

EL 16 power [kW] FC 16/S Power [kW] FC 16/SVoltage

50

51

Time Power W Status Voltage

Time Power W Status Voltage

27/05/2015 01:53:00 0 0 49.014

27/05/2015 01:58:30 0 0 48.877998

27/05/2015 01:53:30 0 0 49.014

27/05/2015 01:59:00 0 0 48.877998

27/05/2015 01:54:00 0 0 48.987

27/05/2015 01:59:30 0 0 48.851002

27/05/2015 01:54:30 0 0 48.987

27/05/2015 02:00:00 858.48767 1 49.681

27/05/2015 01:55:00 0 0 48.945999

27/05/2015 02:00:30 1134.0006 1 49.911999

27/05/2015 01:55:30 0 0 48.945999

27/05/2015 02:01:00 1775.5584 1 50.442001

27/05/2015 01:56:00 0 0 48.918999

27/05/2015 02:01:30 1614.144 1 50.442001

27/05/2015 01:56:30 0 0 48.877998

27/05/2015 02:02:00 1813.719 1 50.605999

27/05/2015 01:57:00 0 0 48.877998

27/05/2015 02:02:30 1701.7056 1 50.646

27/05/2015 01:57:30 0 0 48.877998

27/05/2015 02:03:00 1821.998 1 50.837002

27/05/2015 01:58:00 0 0 48.877998

27/05/2015 02:03:30 1657.5245 1 50.782001 Table 4.2.16 AP 16 Fuel Cell start, 27/05/2015

Another problem occurs when the fuel cell shuts down, from the data in table 4.2.17, the voltage increases above the 52.5 V shut down threshold at 06:48:30 but the machine continues to operate an extra ten minutes until 06:59:30.

Time Power W Status Voltage

Time Power W Status Voltage

27/05/2015 06:48:00 1191.482 1 52.442001

27/05/2015 06:55:00 1068.4598 1 52.999001

27/05/2015 06:48:30 1146.164 1 52.673

27/05/2015 06:55:30 1069.2864 1 53.040001

27/05/2015 06:49:00 1113.89 1 52.741001

27/05/2015 06:56:00 1069.8307 1 53.067001

27/05/2015 06:49:30 1148.232 1 52.768002

27/05/2015 06:56:30 1070.375 1 53.094002

27/05/2015 06:50:00 1115.326 1 52.808998

27/05/2015 06:57:00 1037.1952 1 53.134998

27/05/2015 06:50:30 1115.896 1 52.835999

27/05/2015 06:57:30 1037.1952 1 53.134998

27/05/2015 06:51:00 1115.896 1 52.835999

27/05/2015 06:58:00 1037.7223 1 53.161999

27/05/2015 06:51:30 1116.467 1 52.862999

27/05/2015 06:58:30 1038.5226 1 53.202999

27/05/2015 06:52:00 1116.467 1 52.862999

27/05/2015 06:59:00 1038.5226 1 53.202999

27/05/2015 06:52:30 1116.467 1 52.862999

27/05/2015 06:59:30 1039.0496 1 53.23

27/05/2015 06:53:00 1117.333 1 52.903999

27/05/2015 07:00:00

27/05/2015 06:53:30 1067.089 1 52.931

27/05/2015 07:00:30 0 0 52.034

27/05/2015 06:54:00 1067.089 1 52.931

27/05/2015 07:01:00 0 0 51.966

27/05/2015 06:54:30 1068.46 1 52.999001

27/05/2015 07:01:30 0 0 52.006001 Table 4.2.17 AP 16 Fuel cell shuts down at incorrect time, 27/05/2015.

51

52

The AP 16 Electrolyser starts as programmed exactly four hours after the fuel cell shuts down. This is shown by the timestamps in table 4.2.18.

Time Power W Voltage

Time Power W Voltage

27/05/2015 10:57:30 0 52.835999

27/05/2015 11:01:00 297.708832 52.862999

27/05/2015 10:58:00 0 52.808998

27/05/2015 11:01:30 4467.0791 53.298

27/05/2015 10:58:30 0 52.808998

27/05/2015 11:02:00 4394.89697 52.808998

27/05/2015 10:59:00 0 52.862999

27/05/2015 11:02:30 4345.17285 52.700001

27/05/2015 10:59:30 0 52.903999

27/05/2015 11:03:00 4308.36426 52.808998

27/05/2015 11:00:00 0 52.835999

27/05/2015 11:03:30 4278.37402 52.700001

27/05/2015 11:00:30 0 52.903999

27/05/2015 11:04:00 4257.24561 52.808998

Table 4.2.18 AP 16 Electrolyser activates without meeting starting conditions

The electrolyser makes a first attempt at shutting down at 17:23 but does not succeed until 18:10. Table 4.2.19 below shows when the electrolyser finally manages to shut down, it also shows the last ten minutes of a fifty minute cycle in which the electrolyser starts and stops every three minutes. In fact, the electrolyser is working as programmed here, the voltage decreases to below 50 V and enters the battery alarm state and shuts down the electrolyser. The reduced load and remaining irradiation caused the voltage to increase to over 52 V restarting the electrolyser. This cycle repeats itself ten times over the course of fifty minutes and shows that further improvements to the autonomous control parameters need to be made.

Time Power W Voltage

Time Power W Voltage

27/05/2015 18:00:30 0 51.707001

27/05/2015 18:06:30 0 49.817001

27/05/2015 18:01:00 0 52.209999

27/05/2015 18:07:00 0 50.945999

27/05/2015 18:01:30 27.467373 52.074001

27/05/2015 18:07:30 0 51.041

27/05/2015 18:02:00 4465.80957 50.347

27/05/2015 18:08:00 0 51.408001

27/05/2015 18:02:30 4352.63965 49.776001

27/05/2015 18:08:30 0 51.639

27/05/2015 18:03:00 0 50.877998

27/05/2015 18:09:00 0 51.842999

27/05/2015 18:03:30 0 51.203999

27/05/2015 18:09:30 0 52.034

27/05/2015 18:04:00 0 51.570999

27/05/2015 18:10:00 25.96184 51.639

27/05/2015 18:04:30 0 51.869999

27/05/2015 18:10:30 4464.75391 50.116001

27/05/2015 18:05:00 0 52.102001

27/05/2015 18:11:00 0 50.415001

27/05/2015 18:05:30 26.865545 51.910999

27/05/2015 18:11:30 0 50.782001

27/05/2015 18:06:00 4454.46875 50.210999

27/05/2015 18:12:00 0 51.014

Table 4.2.19 Electrolyser repeatedly resets before shut down, 27/05/2015

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Looking at AP 15 activities for this day, Figure 4.2.4 shows that the fuel cell did not start throughout the night and only the single electrolyser left in the AP 15 machine was operational on this day.

Figure 4.2.4 AP 15 Fuel Cell and electrolyser activities 27/05/2015

Table 4.2.20 below shows that there has been another error and that the fuel cell should have started on this morning. The higher threshold for this fuel cell was set for the voltage to remain below 48.5 V for 300 seconds before the fuel cell activates. This clearly happens but the fuel cell does not start. There may be a problem with the voltage measurements because the recorded readings remain unchanged over consecutive minutes.

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12:00:00 AM 3:00:00 AM 6:00:00 AM 9:00:00 AM 12:00:00 PM 3:00:00 PM 6:00:00 PM 9:00:00 PM 12:00:00 AM

VkW

Time

EL 15 power [kW] FC 15/M Power [kW] FC 15/M…

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Time Power W Status Voltage

Time Power W Status Voltage

27/05/2015 01:56:30 0 0 48.484001

27/05/2015 01:59:30 0 0 48.457001

27/05/2015 01:57:00 0 0 48.484001

27/05/2015 02:00:00 0 0 48.457001

27/05/2015 01:57:30 0 0 48.484001

27/05/2015 02:00:30 0 0 48.457001

27/05/2015 01:58:00 0 0 48.484001

27/05/2015 02:01:00 0 0 48.484001

27/05/2015 01:58:30 0 0 48.484001

27/05/2015 02:01:30 0 0 48.484001

27/05/2015 01:59:00 0 0 48.484001

27/05/2015 02:02:00 0 0 48.457001 Table 4.2.20 AP 15 Fuel cell should start, 27/05/2015.

The AP 15 electrolyser does start at the correct time when the fuel cell voltage exceeds 52 V, as shown in the table 4.2.21. Because the fuel cell didn't start the previous evening, there was no fuel cell timer condition to prevent the electrolyser from starting, so the electrolyser entered a low battery alarm state the previous evening and restarted in the morning as soon as the electrolyser restart threshold voltage was reached.

Time Power W Voltage

Time Power W Voltage

27/05/2015 07:04:00 0 51.869999

27/05/2015 07:06:30 2.201717 51.966

27/05/2015 07:04:30 0 51.910999

27/05/2015 07:07:00 80.778999 51.966

27/05/2015 07:05:00 0 51.938

27/05/2015 07:07:30 329.159027 51.966

27/05/2015 07:05:30 0 51.966

27/05/2015 07:08:00 1060.42883 51.869999

27/05/2015 07:06:00 0 52.006001

27/05/2015 07:08:30 2034.80396 51.707001

Table 4.2.21 AP 15 Electrolyser starts correctly, 27/05/2015.

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Much like the AP 16 electrolyser, the AP15 electrolyser does not shut down properly. Table 4.2.22 shows that it had repeated restarts from 17:24 until 18:10 when it finally shuts down. The 50 V low battery alarm state seems to work as programmed but the thresholds voltages which have been programmed may be too close to each other.

Time Power W Voltage

Time Power W Voltage

27/05/2015 17:59:00 0 51.176998

27/05/2015 18:06:00 882.133362 50.347

27/05/2015 17:59:30 0 51.34

27/05/2015 18:06:30 1918.05994 49.776001

27/05/2015 18:00:00 0 51.869999

27/05/2015 18:07:00 0 51.041

27/05/2015 18:00:30 0 51.938

27/05/2015 18:07:30 0 51.502998

27/05/2015 18:01:00 52.653748 52.006001

27/05/2015 18:08:00 0 51.801998

27/05/2015 18:01:30 234.51001 52.074001

27/05/2015 18:08:30 0 51.966

27/05/2015 18:02:00 809.844666 50.537998

27/05/2015 18:09:00 0 51.910999

27/05/2015 18:02:30 1900.48926 49.817001

27/05/2015 18:09:30 56.400749 51.869999

27/05/2015 18:03:00 0 50.973

27/05/2015 18:10:00 263.470154 51.775002

27/05/2015 18:03:30 0 51.476002

27/05/2015 18:10:30 880.36554 50.415001

27/05/2015 18:04:00 0 51.910999

27/05/2015 18:11:00 0 50.306

27/05/2015 18:04:30 0 52.006001

27/05/2015 18:11:30 0 50.945999

27/05/2015 18:05:00 56.39151 52.034

27/05/2015 18:12:00 0 51.244999 Table 4.2.22 AP 15 Electrolyser incorrect shut down, 21/05/2015.

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4.3 Energy Production and Management 16th of March-18th of March

These consecutive days were selected for analysis because they fall into a period of the timeline when the energy system was supplying a full load to Phi Suea House, all the electrolysers and fuel cells were operational and the Heliocentris data was being collected by the server. In essence, these days represent the hydrogen energy system operating to its potential with many of the errors and system malfunctions having been filtered out throughout the testing period, although not all of the internal communication issues have been resolved. Figure 4.3.1 is a visualisation of the loads supplied, the power produced and the hydrogen levels stored in the tanks over the three days.

Figure 4.3.1 Energy production and load distribution 16/03/2015 - 18/03/2015

For the most part, it seems as though all systems are operating as they should: the fuel cells are active at night with the combined output from the two fuel cells represented by the areas shaded in yellow; the electrolysers, which are now under the direction of a

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4.3 Energy Production and Management 16th of March-18th of March

These consecutive days were selected for analysis because they fall into a period of the timeline when the energy system was supplying a full load to Phi Suea House, all the electrolysers and fuel cells were operational and the Heliocentris data was being collected by the server. In essence, these days represent the hydrogen energy system operating to its potential with many of the errors and system malfunctions having been filtered out throughout the testing period, although not all of the internal communication issues have been resolved. Figure 4.3.1 is a visualisation of the loads supplied, the power produced and the hydrogen levels stored in the tanks over the three days.

Figure 4.3.1 Energy production and load distribution 16/03/2015 - 18/03/2015

For the most part, it seems as though all systems are operating as they should: the fuel cells are active at night with the combined output from the two fuel cells represented by the areas shaded in yellow; the electrolysers, which are now under the direction of a

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new minimum irradiation level condition, activate in the mornings shortly after the fuel cells shut down; the PV system is producing power in direct proportion to the daily irradiation levels; the batteries are charging during the day using the excess power after the load is supplied to the site and electrolysers; the battery is providing the load at night before the fuel cells activate, shown by the area in pale blue.

Two observations can be quickly made, the first is that a particularly high load is recorded on the evening of the 17th and the early hours of the 18th, this is due to the swimming pool pumps being left on overnight. The second is that the hydrogen storage tank levels, represented by the orange curve, are increasing and decreasing at a rate reflecting the energy used and supplied by the two AP boxes.

Between 08:00 of the 16/03/2016 and 08:00 of the 18/03/2016:

428.4 kWh were produced by the PV system 146.28 kWh were used by the four electrolysers to produce 35,539 litres of

hydrogen 28.46 kWh were produced by the two fuel cells consuming 21,342 litres of

hydrogen gas The energy provided across the site was 242.88 kWh 39.2 kWh of energy were used to charge the battery.

A closer look is required to see if the correct conditions are being met for the system to run autonomously in the most efficient way possible.

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Figure 4.3.2 AP M Electrolyser and fuel cell operations 16/03/2015 - 18/03/2015

Figure 4.3.2 represents AP M and shows the voltage levels of the fuel cell, the power supplied by the fuel cell and the load supplied to the two electrolysers. The fuel cell correctly stops producing power at 07:33:00 on the morning of the 16th when it's voltage increase to above 52 V. With the voltage remaining over 52 V, the electrolyser is waiting for the suns irradiation levels to increase to 250w/m2 before it can start producing hydrogen. This happens at 08:26:30 and both electrolysers produce hydrogen gas until 16:25 as shown in table 4.3.2 with the corresponding irradiation levels in table 4.3.1. The electrolysers then restart and shut down on four occasions before staying off for the evening. This could be due to irregular irradiation levels caused by cloud cover and their effects on excess PV battery charging. The irradiation values are only measured every fifteen minutes and in between each measured reading, the levels might be fluctuating around the threshold causing the restarts. On this day, the two AP M electrolysers used 33.96 kWh and produced 8224 litres of hydrogen gas.

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16/03 06:00 16/03 15:00 17/03 00:00 17/03 09:00 17/03 18:00 18/03 03:00 18/03 12:00

VoltagekW

Time

EL 15 power [kW] FC 15/M Power [kW] FC 15/MVoltage

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Time Irradiation W/m2

Irradiation Irradiation W/m2

16/03/2016 16:15 314.13

16/03/2016 17:00 177.93

16/03/2016 16:30 209.82

16/03/2016 17:15 207.24

16/03/2016 16:45 166.38

16/03/2016 17:30 132.38 Table 4.3.1 Irradiation levels for Electrolyser shut down, 16/03/2016.

Time Power W Voltage

Time Power W Voltage

16/03/2016 16:23:30 4139.90137 50.116001

16/03/2016 16:35:00 0 51.082001

16/03/2016 16:24:00 4138.72656 50.048

///////////////////////////////////////////////////////

16/03/2016 16:24:30 4138.72656 50.048

16/03/2016 16:39:00 0 52.237999

16/03/2016 16:25:00 4139.59815 50.143002

16/03/2016 16:39:30 0 51.910999

16/03/2016 16:25:30 0 50.810001

16/03/2016 16:40:00 3134.92041 51.271999

16/03/2016 16:26:00 0 51.313

16/03/2016 16:40:30 4391.0957 50.306

16/03/2016 16:26:30 0 51.476002

16/03/2016 16:41:00 4332.3999 50.007

/////////////////////////////////////////////////////

16/03/2016 16:41:30 0 50.577999

16/03/2016 16:30:00 0 51.966

16/03/2016 16:42:00 0 51.136002

16/03/2016 16:30:30 0 52.006001

16/03/2016 16:42:30 0 51.176998

16/03/2016 16:31:00 0 51.570999

//////////////////////////////////////////////////////

16/03/2016 16:31:30 3582.86133 50.973

16/03/2016 17:12:30 4186.41016 51.176998

16/03/2016 16:32:00 4346.5376 50.374001

16/03/2016 17:13:00 4181.76318 51.109001

16/03/2016 16:32:30 4302.38086 50.306

16/03/2016 17:13:30 4178.26953 50.509998

16/03/2016 16:33:00 4285.78027 50.210999

16/03/2016 17:14:00 4175.94141 50.537998

16/03/2016 16:33:30 4268.1377 50.075001

16/03/2016 17:14:30 4173.02197 50.143002

16/03/2016 16:34:00 4257.5791 49.98

16/03/2016 17:15:00 0 49.884998

16/03/2016 16:34:30 0 50.837002

16/03/2016 17:15:30 0 50.714001 Table 4.3.2 AP M Electrolyser restarts several times before shut down, 16/03/2016.

Following the eventual electrolyser shut down and the end of PV power production for the day, the battery temporarily takes responsibility to supply the load. At 21:47, the fuel cell tries to start despite none of its thresholds being met. The readings in the table 4.3.3 below show that its status remains active throughout the night and the fuel cell attempts but fails to produce power until it finally succeeds to start continuous operation at 00:52, three hours after its first attempts.

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Time Power W Status Voltage

Time Power W Status Voltage

16/03/2016 21:46:00 0 0 49.055

16/03/2016 22:19:30 770.45856 1 49.217999

16/03/2016 21:46:30 0 0 49.055

16/03/2016 22:20:00 0 1 49.178001

16/03/2016 21:47:00 0 0 49.055

16/03/2016 22:20:30 770.45856 1 49.217999

16/03/2016 21:47:30 0 1 49.014

16/03/2016 22:21:00 0 1 49.178001

16/03/2016 21:48:00 0 1 48.945999

16/03/2016 22:21:30 0 1 48.715

16/03/2016 21:48:30 0 1 48.987

////////////////////////////////////////////////////////

16/03/2016 21:49:00 0 1 48.945999

17/03/2016 00:50:00 0 1 48.877998

16/03/2016 21:49:30 0 1 48.987

17/03/2016 00:50:30 0 1 48.416

16/03/2016 21:50:00 0 1 48.945999

17/03/2016 00:51:00 0 1 48.918999

16/03/2016 21:50:30 0 1 48.945999

17/03/2016 00:51:30 852.40405 1 49.409

/////////////////////////////////////////////////////

17/03/2016 00:52:00 1482.1831 1 49.884998

16/03/2016 22:18:30 0 1 49.217999

17/03/2016 00:52:30 1795.6838 1 50.183998

16/03/2016 22:19:00 0 1 49.178001

17/03/2016 00:53:00 1549.7169 1 50.007 Table 4.3.3 AP M fuel cell doesn't start as programmed, 16/03/2016

On the morning of the 17th, the fuel cell once again correctly shuts down when the 52 V threshold is reached. Throughout this morning, the fuel cells produced 10.71 kWh. The electrolysers begin hydrogen production after the sun rises and the irradiation reaches the conditional starting levels. The electrolysers function as expected and throughout the day their combined effort uses 35.79 kWh to produce 8675 litres of hydrogen. They shut down correctly at 17:03 when the irradiation level decreases below the threshold.

The fuel cell does not start on the evening of the 17th or on the morning of the 18th. This is yet another indication that there is still an error in the system programming. Table 4.3.4 below shows that at 04:43, the fuel cell voltage decreases to below 48.8 V for over a 300 second period but does not manage a successful start.

Time Power W Status Voltage

Time Power W Status Voltage

18/03/2016 04:39:30 0 0 48.715

18/03/2016 04:43:30 0 0 48.715

18/03/2016 04:40:00 0 0 48.646999

18/03/2016 04:44:00 0 0 48.688

18/03/2016 04:40:30 0 0 48.688

18/03/2016 04:44:30 0 1 48.646999

18/03/2016 04:41:00 0 0 48.715

18/03/2016 04:45:00 0 1 49.217999

18/03/2016 04:41:30 0 0 48.688

18/03/2016 04:45:30 0 1 49.217999

18/03/2016 04:42:00 0 0 48.646999

18/03/2016 04:46:00 0 1 49.217999

18/03/2016 04:42:30 0 0 48.688

18/03/2016 04:46:30 534.6059 1 49.217999

18/03/2016 04:43:00 0 0 48.646999

18/03/2016 04:47:00 0 1 48.646999 Table 4.3.4 AP M Fuel start not activating when thresholds are met, 18/03/2015.

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Figure 4.3.3 shows the fuel cell and electrolyser activity for the AP S box. On the morning of the 16th the fuel cell shuts down as expected at 07:35 when the fuel cell voltage reaches 52 V. The two electrolysers correctly activate at 08:26 when the irradiation reaches the minimum acceptable level of 250 W/m2 and they both shut down at 17:26 . Throughout the day they use 37.31 kWh of energy to produce 9109 litres of hydrogen.

Figure 4.3.3 AP S Electrolyser and fuel cell operations 16/03/2015 - 18/03/2015

Just like AP M fuel cell, the AP S fuel cell does not start when the correct conditions are reached. Table 4.3.5 shows that after the voltage goes below the 48.8 V threshold for 300 seconds, the fuel cell attempts a start and its status changes to "active" but it does not begin continuously producing energy until 00:02, it is not known why this happens. This period of energy production continues until 7:30 when the fuel cell correctly shuts down when the 52 V threshold is reached. Throughout the night 8.85 kWh are produced by AP S.

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VoltagekW

Time

EL 16 power [kW] FC 16/S Power [kW] FC 16/SVoltage

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Time Power W Status Voltage

Time Power W Status Voltage

16/03/2016 23:30:30 0 0 48.756001

16/03/2016 23:34:30 0 0 48.646999

16/03/2016 23:31:00 0 0 48.783001

16/03/2016 23:35:00 0 1 48.688

16/03/2016 23:31:30 0 0 48.783001

16/03/2016 23:35:30 0 1 48.987

16/03/2016 23:32:00 0 0 48.756001

16/03/2016 23:36:00 422.56186 1 48.987

16/03/2016 23:32:30 0 0 48.688

16/03/2016 23:36:30 0 1 48.987

16/03/2016 23:33:00 0 0 48.646999

16/03/2016 23:37:00 0 1 48.945999

16/03/2016 23:33:30 0 0 48.715

16/03/2016 23:37:30 0 1 49.014

16/03/2016 23:34:00 0 0 48.688

16/03/2016 23:38:00 0 1 48.756001 Table 4.3.5 AP S Fuel cell meets conditions to activate but does not produce power, 16/03/2016

The AP S electrolysers are correctly activated again at 8:22 and do not shut down until 17:27. During the day, the two electrolysers consume 39.22 kWh of energy to produce 9531 litres of hydrogen.

The fuel cell correctly starts up again at 04:44 after the 48.8 V threshold has been met and then it correctly shuts down less than three hours later at 07:32 after having produced 3.19 kWh.

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5. Conclusions and Recommendations The Phi Suea House project demonstrates the viability and potential of using a hydrogen energy storage system to manage and supply power to a micro-grid system, but it has also found that there are still many areas where modifications to the hardware, firmware and software of the Heliocentris power box can be made to help ensure more reliability and improved efficiency. The following paragraphs will attempt to make a few suggestions based on the experiences documented in this report and a few additional observations.

5.1 Hardware A major issue which has already been resolved is the leaking connectors that deliver water to the electrolysers. After the second leak occurred in AP 16/M it was quickly concluded that a manufacturing error was at fault and new connectors had to be made and fitted. The impact of the leakage incidents was significantly worsened by the fact that the electronic control module and power connections are located on the bottom of the Heliocentris Power boxes that are used in the Phi Suea House. This placement of modules inside the cabinet comes with a very high inherent risk - if a leak occurs, gravity will ensure that the electronic control module becomes collateral damage. This could avoided if the AP box could were designed to position all electronic control components above the electrolysers and fuel cell. Sensors that detect a water leak might also be considered as an additional warning system. The first leak in the system occurred on the 26th of March. The main repair activity (replacement of the broken electrolyser stack, fuel cell stack, and all water inlet and outlet connectors on the electrolyser stacks) took place on the 25th of October. The second malfunctioning electrolyser stack was not able to be repaired until the 15th of January 2016.

The initial service and repair of the system after the first leak took almost seven months, which is not within industry standard timeframes for a critical piece of infrastructure such as an off-grid energy supply. Taking into account the additional broken electrolyser stack, the system was not 100% functional for a consecutive nine-and-a-half months.

In addition to the leaks, one fuel cell module and three electrolyser stacks have had to be completely replaced up to this point. As discussed in the report, the fuel cell of AP M was replaced by Heliocentris after a problem with a PWM modulator was confirmed, one electrolyser stack dropped in production in June 2015, eventually failed completely and was replaced in October 2015, another electrolyser was found to be leaking hydrogen gas during the repair activities in October 2015 (this module had water flowing

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through it from the leak in the upper module), and finally another module was returned to Italy after a stack voltage error occurred on the 3rd of March 2016. The repaired module is expected to be shipped back to Chiang Mai at the end of June 2016.

It was not part of the scope of the data analysis in this report, but it is worth noting that there are also some difficulties in managing the temperature of the AP boxes at the Phi Suea House. Maintaining the temperature of each AP box within the safe limits is not possible with the door of the cabinets closed during the summer time. The ventilation fans do not extract sufficient heat from the cabinets. With local temperatures reaching upwards of 40⁰C, not much activity is required to increase the internal box temperatures to beyond 45⁰C, where the fuel cell will activate the high temperature warning light. The problem is resolved by simply leaving the cabinet doors open, however this creates a greater risk of damage to the modules due to dust and easy entrance for insects. Depending on which area of the world an AP box might be designated for use, extra design measures should be included to help regulate the internal temperature.

5.2 Monitoring System The data collection system is very awkward to work with. As discussed earlier, much of the data was lost due to connectivity problems to the Heliocentris server in Italy. The data that was analysed in this report had to be downloaded in groups of three parameters, because the Heliocentris server repeatedly crashed when attempts to download larger data sets were made. The Heliocentris web server has either been down or recording inaccurate information for a total of 37 days and it is unknown what gaps in information are due to connectivity problems in Chiang Mai. A local server or data collection and storage system should be used to guarantee access to all data whenever required and to avoid losing valuable information.

The following are suggestions for extra parameters that might be measured to help improve system analysis:

Volumes of hydrogen entering the fuel cell. A reliable count of the number of starts/stops carried out by each electrolyser

and fuel cell module A reliable count of power/hydrogen flow/runtime for each individual

electrolyser as opposed to the combined numbers provided for the pairs of electrolysers in each AP box.

The AP error and alarm system needs to be more user friendly. When an alarm is activated, a light switches on in the AP box but with no indication as to what is causing it. To find out what the problem is, the Heliocentris server needs to be accessed, the

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relevant error code downloaded and then deciphered using the tables which have been attached in the appendix. Considering that over 3000 errors were recorded over the sixteen months, of which many seemed somewhat irrelevant, it is clearly not practical to check the data and investigate the error code every time the alarm goes off. The current system requires regular observation of the recorded data which defies the logic of having an automated system. The first issue is to understand why so many errors were counted and then to make appropriate changes to the system to try to drastically reduce this. Then when a problem occurs an email or text message should be sent, in written language as opposed to code, to the person responsible for the system to give them an opportunity to resolve issues quickly.

5.3 Control System When reading chapter 4, it is easy to see that the conditions which have been set to activate and shut down the fuel cells and electrolysers are not always being implemented correctly by the firmware communication system. This is the brain of the AP box and when it is not functioning correctly the different mechanisms within the boxes are operating at the wrong times, restarting all too frequently or not at all which will in turn reduce the expected lifespan and efficiency for each part. In the final example of the 16th of March in chapter four, it seems as though many of these communication issues have been resolved. In fact, until the in-depth data analysis and writing of this report, it was thought that all systems were operating as programmed.

After a deeper look, it was found that the condition which activates the fuel cell and the electrolyser were not always functioning as expected and these controls need to be improved. Regarding electrolyser control, it was found that the system will still have multiple start-stop cycles, particularly in the afternoon, where low light conditions cause the battery voltage to fluctuate around the "low battery alarm" thresholds. Possible solutions would be to have a timer increasing the amount of time that must pass between activations, or to add a condition where the electrolysers can't start within a certain time period before the sun sets. Regarding the fuel cell control, it was found that the control system seems to be quite erroneous, sometimes failing to start the fuel cells at the correct time. Due to the nature of the fuel cell directly connected to the lead-acid battery banks and the batteries normally charged to above 90%, the fuel cells also rarely produce the full nominal 2kW of power. An additional DC/DC converter, battery charger or other connection point could be installed between the fuel cell and the battery systems to allow the fuel cells to operate to their full potential.

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List of Figures Figure 1.1.1 Energy management facility with solar array .......................................................................................... 5 Figure 1.1.2 PV arrays at Phi Suea House ................................................................................................................ 6 Figure 1.2.1 Energy Management Facility Plan .......................................................................................................... 7 Figure 1.2.2 Energy Management Facility 3-D visualization ....................................................................................... 8 Figure 1.3.1 Energy flow diagram during periods of Photovoltaic energy production ................................................... 9 Figure 1.3.2 Multicluster and Load Distribution boxes .............................................................................................. 10 Figure 1.3.3 Energy Flow diagram during periods of hydrogen energy production .................................................... 11 Figure 1.3.4 SMA inverters ...................................................................................................................................... 12 Figure 1.4.1 Two Heliocentris Acta Power 1000 boxes ............................................................................................ 13 Figure 1.4.2 Hydrogen Room .................................................................................................................................. 14 Figure 1.5.1 Hydrogen load distribution with battery support .................................................................................... 16 Figure 1.5.2 Two 2000Ah 48V battery banks ........................................................................................................... 16 Figure 3.1.1 Rates of hydrogen production per day in AP 15 Electrolyser Module 1 ................................................. 28 Figure 4.1.1 Energy production and management 28/04/2015 ................................................................................. 35 Figure 4.1.2 Energy production and load distribution 28/04/2015 ............................................................................. 36 Figure 4.2.1 AP 16 Electrolyser and fuel cell operations 21/05/2015 ........................................................................ 40 Figure 4.2.2 AP 15 Fuel cell operations (AP 15 EL power data recording error) 21/05/2015 ..................................... 45 Figure 4.2.3 AP 16 Fuel cell and electrolyser operations. 27/05/2015 ...................................................................... 50 Figure 4.2.4 AP 15 Fuel Cell and electrolyser activities 27/05/2015 ......................................................................... 53 Figure 4.3.1 Energy production and load distribution 16/03/2015 - 18/03/2015 ......................................................... 56 Figure 4.3.2 AP M Electrolyser and fuel cell operations 16/03/2015 - 18/03/2015 ..................................................... 58 Figure 4.3.3 AP S Electrolyser and fuel cell operations 16/03/2015 - 18/03/2015 ..................................................... 61

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List of Tables Table 1.1.1 Sunny Tripower inverter specifications .................................................................................................... 7 Table 3.2.1 List of error codes and descriptions ....................................................................................................... 32 Table 3.2.2 Count of errors per module ................................................................................................................... 33 Table 4.2.1 AP 16 Fuel Cell not producing power after start, 21/05/2015. ................................................................ 40 Table 4.2.2 AP 16 Fuel Cell starts, 21/05/2015. ....................................................................................................... 41 Table 4.2.3 AP 16 Fuel cell not shutting down after exceeding 52.5 V threshold, 21/05/2015 ................................... 41 Table 4.2.4 AP 16 Fuel cell shutting down for unknown reason, 21/05/2015. ........................................................... 42 Table 4.2.5 AP 16 Electrolyser Starts, 21/05/2015. .................................................................................................. 42 Table 4.2.6 AP 16 Electrolyser shuts down and restarts several times for unknown reasons, 21/05/2015. ................ 43 Table 4.2.7 AP 16 Electrolyser shuts down after several restarts 21/05/2015 ........................................................... 44 Table 4.2.8 Incorrect AP 15 EL Power readings ...................................................................................................... 45 Table 4.2.9 Fuel cell does not produce power when active, 21/05/2015. .................................................................. 46 Table 4.2.10 AP 15 Fuel cell starts producing power, 21/05/2015. ........................................................................... 47 Table 4.2.11 AP 15 Fuel Cell shuts down, 21/05/2015. ............................................................................................ 47 Table 4.2.12 AP 15 Fuel cell showing unusual behaviour, 21/05/2015 ..................................................................... 48 Table 4.2.13 AP 15 Electrolyser starts, 21/05/2015.................................................................................................. 48 Table 4.2.14 AP 15 Fuel cell and electrolyser trying to operate simultaneously, 21/05/2015 ..................................... 49 Table 4.2.15 Fuel cell status as operational but not producing power, 27/05/2015.................................................... 50 Table 4.2.16 AP 16 Fuel Cell start, 27/05/2015 ........................................................................................................ 51 Table 4.2.17 AP 16 Fuel cell shuts down at incorrect time, 27/05/2015. ................................................................... 51 Table 4.2.18 AP 16 Electrolyser activates without meeting starting conditions ......................................................... 52 Table 4.2.19 Electrolyser repeatedly resets before shut down, 27/05/2015 .............................................................. 52 Table 4.2.20 AP 15 Fuel cell should start, 27/05/2015. ............................................................................................ 54 Table 4.2.21 AP 15 Electrolyser starts correctly, 27/05/2015. .................................................................................. 54 Table 4.2.22 AP 15 Electrolyser incorrect shut down, 21/05/2015. ........................................................................... 55 Table 4.3.1 Irradiation levels for Electrolyser shut down, 16/03/2016. ...................................................................... 59 Table 4.3.2 AP M Electrolyser restarts several times before shut down, 16/03/2016. ............................................... 59 Table 4.3.3 AP M fuel cell doesn't start as programmed, 16/03/2016 ....................................................................... 60 Table 4.3.4 AP M Fuel start not activating when thresholds are met, 18/03/2015. .................................................... 60 Table 4.3.5 AP S Fuel cell meets conditions to activate but does not produce power, 16/03/2016 ............................ 62

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