NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

Michael Milligan & Brendan Kirby (consultant)National Renewable Energy Laboratory

Golden, Colorado USA

Ongoing NREL ResearchOn BA Cooperation

NREL Research Efforts

• Western Wind and Solar Integration Study• Eastern Wind Integration & Transmission Study• Potential Benefits of Balancing Area Cooperation and

Wide-Area Management Approaches in the Western Interconnection– Quantify the potential benefits of reducing net variability and

increasing response capability through cooperation among BAs

– Many methods to share variability and response– Joint NREL/PNNL Virtual BA project

2

Benefits of Balancing Area Cooperation:Genuine Economies

• Reduce net variability– Uncorrelated and partly correlated variability are reduced through

aggregation• Regulation and load following

– Load– Wind– Load & wind

• Increase resource access– Larger geography & resource pool – greater probability of excess

maneuvering capability– Sub-hourly scheduling gains access to “Stranded” ramping

capability• Utility owned & IPP• Generation and responsive load

3

Multiple Beneficiaries

•Generators benefit Increased sales

opportunities

•BAs benefit Increased resource pool

•Customers benefit Decreased ancillary service

costs

•Wind benefits Decreased integration costs

4

Minute-to-Minute Regulation Requires Additional Capacity

(Load and Wind)

Capacity to Serve Varying Load

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Installed CapacityLoadExtra Capacity

Capacity to Serve Ramping Load

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Load Ramps Do Not Require Additional

Capacity – Just Additional Movement Of Existing

Capacity

Capacity Requirements Differ For Regulation and Ramps

Capacity Requirements Differ for Wind Serving “Internal” vs “External” Load

Wind Serves Internal CA Load

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Installed CapacityGenerationLoadWindExtra Capacity

Wind Serving Internal BA Load Does Not Require Additional

Capacity – Just Additional Use of Existing Capacity

Wind Serves External Load

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Installed CapacityGenerationLoadWindExtra Capacity

Wind Serving External BA Load Does Require Additional Capacity – (But That Capacity Is Not Very

Useful To The Receiving BA)

What You Do vs How You Do It

• Many methods to accomplish the same goal– Reserve sharing pools

– Dynamic schedules between resources

– Dynamic scheduling with BAs

– Sub-hourly resource scheduling

– Sub-hourly BA scheduling

– …

– Control area consolidation

• Result can be separated from implementation method or industry structure– Vertically integrated

– Fully restructured

– …

• Analysis is quite similar

National Renewable Energy Laboratory Innovation for Our Energy Future

Initial Analysis and Data

• Unconstrained “copper sheet” analysis quantifies the upper bound on cooperative benefits

• Initial data– 10 minute load from 106 areas within WECC for 2006

– 10 minute wind data from WWSIS

• Initial analysis possibilities– Compare variability over time frames of interest

• Minute-to-minute regulation• Sub-hourly and hourly load following• Infrequent, large ramps (tails events)

– Compare alternative levels of collaboration• Individual BA• Aggregate load, Aggregate wind, Aggregate wind and load• Sub-hourly vs hourly scheduling

– With generators– Between BAs

National Renewable Energy Laboratory Innovation for Our Energy Future

National Renewable Energy Laboratory Innovation for Our Energy Future

• Methodology for Examining Control Area Ramping Capabilities with Implications for Wind

• The Impact of Balancing Areas Size, Obligation Sharing, and Ramping Capability on Wind Integration

• An Analysis of Sub-Hourly Ramping Impacts of Wind Energy and Balancing Area Size

• Capacity Requirements to Support Inter-Balancing Area Wind Delivery

References: Various papers by Milligan & Kirby

National Renewable Energy Laboratory Innovation for Our Energy Future

Additional FY 2010 Tasks

• Production cost simulation– Wind penetration and locations to be developed with VGS– Hydro scheduling and dispatch– Production cost and other metrics as desired by the VGS– Sub-hourly scheduling impacts on resource availability

• Identify sources of flexibility and tap those that are economic

• Show impact of new transmission, demand response, wind only BAs, etc.

– Quantify both physical and economic benefits– Physical and institutional constraints

National Renewable Energy Laboratory Innovation for Our Energy Future

FY 2010 Tasks (continued)

Canadian and Mexican renewable resources are not included in WWSIS

• Develop 3-year meso-model (wind) for the rest of WECC

• Coordinate time-synchronized load and wind data

• Develop full WECC model– Possibly with TEPPC