der integration - plma.memberclicks.net · revolutions per changes, meaning its frequency changes...
TRANSCRIPT
© 2018 Austin Energy
DER IntegrationBridging the Operations/Program Divide
November 12, 2018
Peak Load Management AllianceInterest Group Meeting
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Agenda
01 Background
02 What is DER Integration?
03 Austin Energy Experience
04 DER System Impacts
05 Breakouts
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L I S A M A R T I ND E R I N T E G R A T I O N
A U S T I N E N E R G Y
A B O U T T H E P R E S E N T E R
Lisa Martin is a Program Manager of Advanced Technology at Austin
Energy. Her focus is in the field of Distributed Energy Resource (DER)
Integration.
Lisa serves as the project manager for Austin SHINES, a federal and
state-funded project that establishes an open standards-based DER
management platform to integrate and optimize DER at several
levels along the utility value chain. Lisa has a BS in Electrical
Engineering and an MBA in Operations Management. She is a
registered Professional Engineer in the State of Texas.
BRIEFBIO
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About Austin EnergyPublic Power• 2nd largest municipally owned utility in Texas• Reports to the City Manager, who executes the policy and direction
of the City Council• 1700+ Employees
Compact, Dense System• 437 square miles of service area covering
City of Austin and beyond• 491,000+ meters (65,000+ C&I)
Vertically-Integrated• Vertically-integrated in a deregulated, wholesale, energy only market• 2018 AE System Peak Load 2878 MW (summer), 2381 MW (winter)
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Offset 65% of customer load with
renewable resources
Austin Energy 2027 Goals
1000 MW of savings from
energy efficiency and demand
response
750 MW utility-scale solar + 200 MW local solar,
including 100 MW customer-sited PV
10 MW battery storage and 20 MW thermal
energy storage
Net zero community-wide GHG emissions by
2050
All subject to meeting Affordability Goals: <2% rate increase per year; Austin Energy rates in lower 50th percentile of statewide utilities
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Enriching the lives of our customers and communities by being their trusted energy Provider, Platform, and Partner
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Distributed Energy Resource (DER) IntegrationThe study of how to interconnect distributed resources and controllable loads into our grid
For customers and the utility this value may looking like• Energy self-supply• Sustainability• Emergent technology• Bill savings• Back-up power capabilities• Grid services• And more…
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Asset Types
=~
DC
AC
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Technology Communications & Control Market
Leveraging Customer-sited Assets to Solve Circuit-level IssuesSame Topic, Three Perspectives during Breakout Sessions
How will technology evolve in the world around us?
How can traditional and new asset types be leveraged to address emerging problems?
What communications pathways/protocols, telemetry requirements, and data integration/
assimilation needs exist?
How will the assets become part of a coordinated system?
How will they be optimized?
What business models will engage the market?
Who are the players and what partnerships/ coordination efforts need to take place?
What incentives/rates/settlements play a part?
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DER at Austin Energy
Solar PV Palmer Events CenterBattery Storage KB ESS, MU ESSDistributed Generation RMEC
OwnSolar 466 MWWind 1219 MWBiomass 107 MW
ContractIncentives and programs for
Demand ResponseElectric VehiclesControllable Loads
Partner
Do we drive DER penetration, accommodate it, or react to it?
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Austin SHINES Concept
Utility Scale Energy Storage + PV
Commercial Energy Storage + PV
Residential Energy Storage + PV
DER Management Platform
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Utility ScaleLa Loma Community Solar
•2.6 MW Photovoltaic solarKingsbery Energy Storage System
•1.5 MW / 3 MWh Li-Ion battery storageMueller Energy Storage System
•1.75 MW / 3.2 MWh Li-Ion battery storage7 Energy Storage Units (250 kW each)
Austin SHINES Assets
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Commercial ScaleAggregated Storage Installations at 3 sites, with existing solar (300+ kW)
•One 18 kW / 36 kWh Li-Ion battery storage•Two 72 kW / 144 kWh Li-Ion battery storage
Residential ScaleAggregated Storage Installations
•Six stationary battery storage systems (10 kWh each) at homes with existing solar
•One Electric Vehicle installed as Vehicle-to-Grid (V2G)
Utility-Controlled Solar via Smart Inverters at 12 homesAutonomously-Controlled Smart Inverters at 6 homes
Austin SHINES Assets
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DER Management System, DG-DEROTM
Fleet-wide controller at T&D control center & energy market desk
Circuit-level control for applications like voltage control
Works with site-level controller or aggregator for field installations
Inputs include grid data, market data and forecasts (weather, load, & price)Distributed Energy Resource Optimizer
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DERO in an Austin Energy Ecosystem
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DR CapabilitiesPeak Load Reduction
for economic or reliability purposes
How can you put more tools in the DR toolbox?
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University of Texas ResearchHighlighting Energetic and Economic Potential for Load Control for
Residential Customers in Austin, Texas
Determine maximum possible peak load (kW) reduction & shifts in total consumption (kWh) by considering operational changes to rooftop solar PV, energy storage systems
(batteries), HVAC, electric vehicles, electric water heaters and pool pumps
©Bandyopadhyay et al, 2018
Arkasama Bandyopadhyay, Julia P. Conger, Michael E. Webber
1818
A load shifting algorithm is applied to the overall load
profile for each appliance to reduce peak demand(Sinha and De, 2016)
©Bandyopadhyay et al, 2018
Priority1. HVAC2. Electric WH3. EV4. Pool Pump
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Issue: Reverse Power Flow
Objective: Consume Power/Shift Load
Issue: Exceeding Thermal Limits
Objective: Congestion Management
1 2
3 4
Issue: Lower System Inertia
Objective: Frequency Support
Issue: Voltage Volatility
Objective: Voltage Support
System Impacts from High DER Penetration
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System Inertia and Frequency
Power grid stability exists when
Supply = DemandGeneration = Load
1
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System Frequency•System frequency is related to
rotational equipment on the grid
• It must remain within a tight tolerance band for the system to remain stable
•Frequency depends on the real power balance, supply and demandRevolutions Per
Minute (RPM)Frequency = cycles/sec
orHertz [Hz]
GENERATOR
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System Frequency•When supply = demand, the
rotating machinery is spinning at a certain rate• When supply and demand get out of
balance, the rotating machinery must either speed up or slow down to compensate
• The rate at which the machinery spins changes, meaning its frequency changesRevolutions Per
Minute (RPM)Frequency = cycles/sec
orHertz [Hz]
GENERATOR
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System Inertia and Frequency
• If generation and load are not balanced, system frequency will change at a rate initially determined by the inertia of the entire system
•Systems with higher inertia are not as affected by a change in the generation/load balance
•That is, inertia sets the rate at which frequency falls after a generator trips offline
Objects at rest tend to stay at rest and objects in motion tend to stay in motion (unless acted on by an outside force)
Law of Inertia:
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Dr. Ning Lu, North Carolina State University
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Impact of Renewables on System Inertia
• In robust systems (higher inertia), system frequency is less sensitive to power imbalances
•But, when more and more renewables are added, system inertia drops
•That is, the system frequency becomes more susceptible to power imbalances
Dr. Ning Lu, North Carolina State University
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Generation Trips OfflineDemand >> SupplyFrequency Drops
Traditional response:
• Generator governors work to cause online generation to ramp up and compensate for lost supply
• If not done quickly enough, UFLS will cause load to drop offline to compensate for excess demand
What can DR do to play a part in the solution?
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Solar Irradiance, Temperature and Voltage Volatility
Power grid stability exists when
Voltage is stable
2
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System Voltage• Photon current, Iph, is dependent upon
the irradiance available at a certain time and location
• If the amount of sunlight on the panel decreases, there is less photon current which would ultimately lead to less output current, I
• As current changes, so does voltageIdeal model of a solar cell
G = irradiance or sunlight intensity, [W/m2]
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https://www.ecmweb.com/green-building/highs-and-lows-photovoltaic-system-calculations
Irradiance impacts on a solar module’s current and voltage curve
Irradiance Impacts on System Voltage
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https://www.ecmweb.com/green-building/highs-and-lows-photovoltaic-system-calculations
Temperature impacts on a solar module’s current and voltage curve
• Temperature changes also impact a solar module’s current and voltage curve
• For a given current (e.g., irradiance is steady) voltage varies by temperature
Temperature Impacts on System Voltage
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Impact of Renewables on System Voltage
•A change in the voltage output may not seem significantly large for a single panel, but as the number of panels increase, the voltage fluctuations increase and it becomes detectable on the distribution level
•Voltage volatility leads to instability which can impact residential and commercial appliances as well as grid-level protection devices and equipment
•We need to maintain voltage in certain tolerance bands, often nominal +/- 5%
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Voltage Support• We often think of smart inverters to
remedy this fix• Can use the inverter for PV or battery
storage to provide voltage support
• Most common method, Volt-VAR
• But what about Volt-Watt?• As load increases, voltage drops• As load decreases, voltage rises
When is Volt-Watt most effective, and what can DR do
to be part of the solution?
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Reverse Power Flow• When rooftop photovoltaic (PV) systems
are connected to the distribution network, local load initially consumes the power produced
• Excess power is used for charging battery storage or flows back to the grid
https://www.befutureready.com/ezine-article/making-way-two-way-power-flows-planning-control-matters/
3
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Detecting Reverse Power Flow•Reverse power flow can be detected by looking at voltage and current
waveforms
•Or by looking at current flowing from the substation
https://web.wpi.edu/Pubs/E-project/Available/E-project-122215-204620/unrestricted/MQP_Final_Report.pdf
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Reverse Power Flow
Impacts:
• Overloading of distribution lines or transformers
• Entry into the substation … transmission level impacts
• Unstable operation of protective equipment• Generally designed for one-way power flow
What can DR do to consume or shift load to offset reverse
power flow conditions?
36
Thermal Overloads• Overloading of lines or equipment is not
necessarily due to high DER penetration
• Still, there is an opportunity for DER to provide value by matching supply and demand locally and relieving overloaded equipment
• Energy storage can provide congestion management• Discharging helps if it can be used to meet local needs• If excess flow on a line, storage can charge (to use that
supply) and prevent overloads further downstream??
4
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Thermal Overloads• Overloading of lines or equipment is not
necessarily due to high DER penetration
How can you use DR to relieve congestion?
How can behind-the-meter loads become aware of congestion so they can remove
themselves from the equation?
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Your goal is to think about DR differently. How can you take the thoughts we’ve just discussed and expand your view of DR and the value it can offer?
DER integration is not about individual assets operating in silos. It’s about using all the tools in your toolbox to create
the right customer experience the full business case a safe, reliable, affordable power system the holistic solution …
©2018 Austin Energy. All rights reserved. Austin Energy and the Austin Energy logo and combinations thereof are trademarks of Austin Energy, the electric department of the City of Austin, Texas. Other names are for informational purposes only and may be trademarks of their respective owners.
Thank you!
Lisa Martin
40
Technology Communications & Control Market
Leveraging Customer-sited Assets to Solve Circuit-level IssuesSame Topic, Three Perspectives during Breakout Sessions
How will technology evolve in the world around us?
How can traditional and new asset types be leveraged to address emerging problems?
What communications pathways/protocols, telemetry requirements, and data integration/
assimilation needs exist?
How will the assets become part of a coordinated system?
How will they be optimized?
What business models will engage the market?
Who are the players and what partnerships/ coordination efforts need to take place?
What incentives/rates/settlements play a part?