Ludington Pumped Storage Plant and Wind Power Operational Considerations David Lapinski Consumers Energy Company June 16, 2009.

Ludington Pumped Storage Ludington Pumped Storage Plant and Wind PowerPlant and Wind Power

Operational ConsiderationsOperational Considerations

David LapinskiConsumers Energy CompanyJune 16, 2009

SummarySummary

Ludington Plant OverviewLudington Plant Overview Operational CharacteristicsOperational Characteristics Past & Current UsePast & Current Use Impacts of increasing wind generationImpacts of increasing wind generation

Ludington Pumped Storage PlantLudington Pumped Storage Plant

Ludington Pumped Storage PlantLudington Pumped Storage Plant

In operation since 1973In operation since 1973 Jointly owned by Consumers Energy and Jointly owned by Consumers Energy and

The Detroit Edison CompanyThe Detroit Edison Company Pond is 2.5 miles x 1 milePond is 2.5 miles x 1 mile Six reversible pump – turbinesSix reversible pump – turbines 360 feet from Lake Michigan to full pond 360 feet from Lake Michigan to full pond

levellevel 27 billion gallons H2O27 billion gallons H2O

LPS OperationLPS Operation

Ludington – Well connected to Ludington – Well connected to transmission systemtransmission system

LPS Key Operating ParametersLPS Key Operating Parameters

1872 MW Generating capacity1872 MW Generating capacity 1960 MW Pumping 1960 MW Pumping 15000+ MWh generation storage15000+ MWh generation storage 70% cycle efficiency70% cycle efficiency Generators quick start & regulation Generators quick start & regulation

capablecapable Pumps quickly interruptiblePumps quickly interruptible

Historic and Current Operational Historic and Current Operational UsesUses

Economic alternative to more expensive Economic alternative to more expensive generation to meet loadgeneration to meet load If value of generation > 1.4 times cost of If value of generation > 1.4 times cost of

pumpingpumping Ancillary Services & flexible response to Ancillary Services & flexible response to

operational uncertaintiesoperational uncertainties

Managing Stored Energy is Managing Stored Energy is ImportantImportant

Predictability of Cost & ValuePredictability of Cost & ValueMISO Day-Ahead LMP

(March 2009)

0

10

20

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1 13 25 37 49 61 73 85 97 109 121 133 145 157

hour of week

LM

P $

/MW

h

Example StrategyEquivalent Energy Stored - MWh

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1 13 25 37 49 61 73 85 97 109 121 133 145 157

Hours

Strategy for economic value, with room for contingenciesStrategy for economic value, with room for contingencies

Potential Impacts of Increased Potential Impacts of Increased Wind EnergyWind Energy

Reduced predictabilityReduced predictability Increased variation in supply-demand Increased variation in supply-demand

balancebalance Other resources required to compensate for Other resources required to compensate for

longer duration variations (10’s of minutes to longer duration variations (10’s of minutes to hours)hours)

Potential for increased need for ramping Potential for increased need for ramping capacity & intermediate term reserves capacity & intermediate term reserves capacitycapacity

MISO Load and Wind Generation Feb 4-5, 2009

0

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40000

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90000

2/3/2009 12:00 2/4/2009 0:00 2/4/2009 12:00 2/5/2009 0:00 2/5/2009 12:00 2/6/2009 0:00 2/6/2009 12:00

Meg

awat

ts

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9000

MISO Load Wind Generation

Storage Technologies Have a RoleStorage Technologies Have a Role

For short term replacement and balancing, For short term replacement and balancing, pumped storage can fill inpumped storage can fill in rapid response for ramping and contingenciesrapid response for ramping and contingencies economic generation to buy time for longer economic generation to buy time for longer

lead time units to come on linelead time units to come on line absorb excess generationabsorb excess generation

Additional ConsiderationsAdditional Considerations

Reliance on accurate wind generation forecasts Reliance on accurate wind generation forecasts Storage Management Storage Management Overall system optimizationOverall system optimization

Optimum storage management changesOptimum storage management changes May require decreasing daily budget of energy May require decreasing daily budget of energy

available to day ahead marketavailable to day ahead market

Limits on ability to cycle pumped storage units to Limits on ability to cycle pumped storage units to compensate for variations.compensate for variations.

Pump mode startup is limitedPump mode startup is limited