Notrees Wind Storage Project Description
Anuja Ratnayake
Duke Energy
October 20, 2011
Special thanks for support from DOE
Project objective:
Provide validation that energy storage increases the value and practical
application of wind generation, alleviates intermittency issues, and is
commercially viable at utility scale
The Energy Storage System will:
Integrate with variable renewable energy production
Improve use of power‐producing assets by storing energy during
non‐peak generation periods
Demonstrate benefits of using fast response energy storage to provide
ancillary services for grid management
Confirm that the solution can dispatch according to market price signals
or pre‐determined schedules utilizing ramp control
Verify that energy storage solutions can operate within the ERCOT
market protocols
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Duke Energy Renewables Overview
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1,030 MW
Today
1,900 MW
2012
In addition to these operating projects, DER has a number of projects under construction, and a development pipeline
of approximately 5,000 MW.
Project site
Notrees wind farm, owned and operated
by Duke Energy Renewables
Located in west Texas – Ector and
Winkler Counties
152.6MW total wind generation capacity
Energy Storage System (ESS) will be
located at the substation and tied on the
distribution side
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Notrees Battery Storage System
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Location:
Notrees, TX
Application:
Notrees
Wind Farm
ESS
Xtreme
Power – DPR
36 MW / 24 MWh
COD
Q4 2012
Value:
Frequency Regulation
Energy Arbitrage
Voltage Support
Wind Firming
Curtailment Mitigation
Other Ancillary Services (Non-
Spinning Reserve, Black Start)
Price:
$43.6
million
36MW/24MW battery storage integrated with an existing Duke wind farm in West Texas
Storage system consists of 24 x 1.5 MVA/1 MWh modules
Connected to the 34.5 kV wind farm collector system
Separate storage control system to enable full visibility by TDSP & ERCOT of storage system
Anticipated Benefits: Regulation Up/Down
0
6
12
18
24
0 24 48 72 96
Battery Level (MWh)
Primary battery usage will likely be providing regulation up/down services
• Must learn how to optimize system within ERCOT market operations
• Current regulation market signals suggest state-of-charge (SOC) drift will occur. Can
we get an energy neutral signal for dispatch, or will bid strategies need to be adjusted
to control for drift?
Drift to max SOC
Drift to min SOC
Desired Upper
Bound for SOC
Desired Lower
Bound for SOC
Anticipated Benefits
7
Source: Xtreme Power
Ramp Control
No mechanism for monetizing this benefit in ERCOT at present
• Will there be defined market value for providing ramp control?
Anticipated Benefits
8
Source: Xtreme Power
Market Challenges
Access to Markets
Settlement
Metering
Registration Complexity
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Current Project Timeline
2009 2010 2011 2012 2013
Phase I
– Economic and Industry Evaluation
Phase II
– Battery
Engineering and
Construction
Phase
III – Battery Testing
Phase
IV – Installation
Phase
V – Commissioning
& Operations
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Accomplishments since last update:
Completed project economic evaluation
Awarded vendor contract to Xtreme Power
Detailed system engineering started August 2011
Site mobilization October 2011
Next Steps
Final system design
Build and install system
System testing and commissioning
Commercial Operations projected for October 1, 2012
PUCT Storage Workshop – October 2011
Establish rules for storage via ERCOT stakeholder process
EPRI will work with Duke Energy to:
Finalize performance testing and analysis plan
Develop system benefits framework
Analyze and report system performance
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