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Good Morning. My name is Alex Cicelsky, director of research and development at Kibbutz Lotan’s Center for Creative Ecology. We’re an education institution focused on teaching practical engineering. We’re been working on sustainable systems development since 1995. We wish to express thanks to the Jewish National Fund for their contribution to this research program. I would like to present to you today the findings of our most recent research into energy efficient building systems.

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The goal of the Center for Creative Ecology’s research and development is to find the most energy efficient designs and sustainable materials for buildings to be built specifically in the southern Arava region. IN Today’s presentation I’ll cover the following. 1. I’ll describe to you the challenges of the Southern Arava’s climate and how that impacts building design and energy use. 2. The buildings that We’ve constructed are unique because of the materials used. But more important is the extent to which we use insulation in the building’s envelope and the placement and quality of the windows. In order to establish the potential savings in electricity use we have been measuring both these new buildings and existing conventional buildings. 3. I’ll present the significant electricity savings that we’ve realized in these experimental buildings both in controlled conditions and when occupied. Which leads us to 4. conclusions that should direct policy goals for new construction in this region.

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Climate. On this temperature gradient map you can see that the average August temperature in the Negev highlands, as measured at sde boker, is between 26 and 28 degrees Celsius. In the southern Arava , part of the Syrio-African rift valley system, the average August temperature is significantly higher, 32-34 degrees.

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This graph shows for Sde Boker and Kibbutz Lotan, the average monthly maximum and minimum exterior air temperatures during the monitoring period of the buildings on kibbutz lotan from November 2010 until October 2011. The significant point to note is the thermal comfort zone of temperatures between 20 and 26 degrees. This is the temperature range in which most people feel comfortable in buildings. Despite the low exterior temperatures in winter that are below Thermal Comfort, Passive Solar houses that are designed to be heated solely by sunlight, reach and maintain interior thermal comfort temperatures in Sde Boker and in Lotan In the summer in sde boker the evening and night time breezes are cool. The temperatures drop below the thermal comfort zone. Evening and night-long ventilation can be used to cool the mass of the buildings. The walls of the buildings heat up slowly from the hot daytime air and solar radiation . They are cooled again in the night by night-long ventilation. On Lotan the evening and night time air temperatures remain hot. They do not go below the thermal comfort zone so the buildings can not be cooled by natural ventilation.

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This aerial view of the EcoCampus shows the 10 “dome-atory” units. Each of the units has a net floor area of 20 square meters. The units housed, on average, 2 eco-volunteers.

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Comparative studies were done between the electricity consumption data from the ecocampus units and from a number of concrete units built in 1983, also with a floor area of 20 square meters, which housed two regular kibbutz volunteers. The concrete units have 20 centimeter thick walls and insulation in accordance with the building code at that time. These units are semi-attached and therefore have a much lower exposed exterior surfaces than do the individual domes. The domes’ walls are 50 cm thick strawbales, encased inside and outside with 5 cm of earth plaster.

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The thick layer of earth on the interior walls serves as thermal mass which buffers the changes of temperatures – that is it retains heat in the winter and, when cooled, absorbs heat in the summer. The ultra thick insulation was chosen so that in the winter the heated interior would remain warm efficiently, and in the hot summer the insulated wall would reduce to a minimum the transfer of heat from the outside walls to the inside. The south facing insulated windows on these passive solar units allow them to heat up from sunlight in the winter.

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The units were hand built by ecovolunteers trained during the construction process. This particular building methodology uses very little steel and concrete.

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Jennifer Golding researched the behaviour of the straw insulated buildings and compared their performance with standard concrete units under controlled conditions – that is with shuttered windows and no residents. The energy needed to cool the dome units was half of that needed to cool the standard concrete units.

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We recently completed a year of monitoring the electricity use of the occupied EcoCampus units as well as from the standard concrete housing units. In both cases the residents decided for themselves when to operate the heat and cooling systems. We compared the daily electricity use data from these two distinct building systems

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This is a graph of the monthly electricity consumption for heating and cooling of each of the types of housing units. This graph includes a plot of the same exterior temperature curves we previously viewed in order to illustrate the correlation between seasonal temperatures and energy use. The red bars are the electricity consumption for heating and cooling in the standard units . The blue bars are the electricity consumption of the ecocampus dome units. The standard units used air conditioners in the winter for heating and in the summer for cooling. The insulated domes needed no electricity for heating in the winter. In the summer the domes used about half as much electricity for air conditioning operation than did the standard units. IN the summer The insulated EcoCampus units need less energy for cooling than did the standard units for a number of reasons. First is the thick insulation which prevents the walls from conducting heat from the outside surfaces of the walls to the interior. Second is internal mass of earth plaster which when cooled serves to reduce the radiant energy experienced by the inhabitants. Third are the highly insulated windows and that also reduce heat transfer. Together they allow the domes to cool down quicker and stay cool longer while consuming less electricity.

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The realized electricity savings when comparing standard units with the passive solar and insulated units are as follows. In the winter – 100%

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In the summer – about half

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And on a yearly basis – 67% less electricity was consumed for heating and cooling in the experimental units than in the standard units.

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So in summary, winter heating can be supplied by solar gain, or very little electricity would be needed as long as the complete building envelope is superbly insulated.

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In the summer time the significant difference in electricity consumption by air conditioners was a function of the interior mass, the insulation of all the elements of the building’s envelope and the reduction of radiation reaching the interior by shuttering the windows. Similar savings can be made in residential houses when properly designed and constructed.

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We planned the photovoltaic system for the EcoCampus based on the measured electricity use in the ecocampus daily and the air conditioners individually. A 3.5 kWp system would produce enough electricity to match the ecocampus’s yearly consumption which would make the ecocampus net energy neutral. A 5.5 kWp system would supply sufficient electricity to match the highest measured monthly consumption. In order to meet the electricity consumption assuming “maximum consumption by all domes” that is all of the air conditioners running at capacity needed to cool all of the domes , A 9.5 kWp system would be needed. Such as system takes up 50 sqm. So only 50 sqm of rooftop is needed to supply all the energy needed for over 200 sqm of energy efficient facilities.

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Therefore we have made a correlation between energy efficient homes which save electricity and the saving of space needed on rooftops or on land that is needed for producing renewable energy for these buildings. In this region with an extreme climate that is concerned about protecting nature while doubling its population - this research presents a win-win paradigm that we suggest should become public policy for development.

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Thank you for your attention. You’re all invited to visit our Center for Creative Ecology at Kibbutz Lotan