the iowa stored energy plant a project review and update may 2005 bob haug, executive director iowa...

The Iowa Stored Energy Plant

A Project Review and Update

May 2005Bob Haug, Executive Director

Iowa Association of Municipal Utilities

Iowa Association of Municipal Utilities - May 2005

Iowa Association of Municipal Utilities (IAMU)

IAMU members include 550 Iowa cities550 municipal water utilities136 municipal electric utilities50 municipal gas utilities27 municipal telecommunications utilities

The Iowa Stored Energy Plant (ISEP) is an IAMU power supply project funded by 109 municipal utilities located in Iowa, Minnesota, and the Dakotas.


The Iowa Stored Energy Plant (ISEP)

3 Proven Technologies3 Proven Technologies

1. Renewable wind energy

2. Aquifer storage of gas

3. Combustion turbine


1. Iowa and municipal wind energy


Distributed wind project - Algona3 turbines (750 kW each)Jointly owned by 7 communitiesLocated within host utility’s distribution system


2. Aquifer storage of gas


Gas storage


3. Combustion turbine (simple cycle)

Natural Gas12,000 BTU/kWh

Air

Air

Compressor Turbine Generator

Combustor


The Alabama CAES plant

CAES Plant at AEPCAES Plant at AEP

Alabama Electric

Cooperative

McIntosh Power Plant

Aerial View


CAES drive train (Dresser Rand)

Motor/Generator and Combustion

Turbine

---------

Motor/Generator and Compressor

Train


Mechanics of CAES – storage

Air

Air

Compressor Turbine Motor/ Generator

Combustor

Aquifer

Clutch

Power in


Mechanics of CAES – generation

Natural Gas 3,800 BTU/kWh

Air

Air

Compressor Turbine Motor/ Generator

Combustor

Aquifer

Clutch

Power out


Mechanics of CAES – reliability/performance

CAES uses well-proven and highly reliable equipment (common used in petroleum refining)

Reliability (from Alabama operation)

Average 218 starts per year (1996-2001)90% starting reliability; >97% running reliability

Quick start capability (Alabama 110 MW unit)

9 min. to full power or 6 min. emergency startup


Mechanics of CAES - performance

Efficiency of operationCAES uses 4,300 BTU/kWh vs. 12,000 BTU/kWh for simple cycle turbines and 7,000 BTU/kWh combined cycle unitsOperates efficiently from 10% to >100 outputEconomically efficient in 100-130 MW incrementsLower temp. (1,600°F vs. 2,200 °F) = longer service life60% lower emissions than GTLow hot-weather capacity degradation

CAES is ideal for delivering ancillary services


Integrating wind and CAES

Wind is low-cost generation sourceWind is not dispatchableCAES provides a battery for windCAES/Wind is dispatchable as an intermediate resource and is very flexible in meeting changing capacity needs

Electric Power Substation at CAES

Power Plant

CAES Power Plant

Operation During Energy Storage or Compression PhaseWind Generation Used to Compress Air

No Extra Grid Power Used

TAW 7/18/2002

Power Flow

Air Flow

Local Wind Farm

Underground AquiferCompressed Air Storage

50 MW

50 MW

0 MW



Power Plant

CAES Power Plant

Operation During Energy Storage or Compression PhaseWind Generation Used to Compress Air

And Supplemental Off-Peak Grid Power Also Used

TAW 7/18/2002

Air Flow


50 MW

25 MW

75 MW

Local Wind Farm



Power Plant

CAES Power Plant

Operation During Energy Generation PhaseCAES Power Plant Generates Power

to Supplement and Firm Up Wind Farm Output

TAW 7/18/2002

PWind

Air Flow


PCAES

20 MW

100 MW

80 MW

Local Wind Farm

Generation & Compression for 100 MW CAES Plant for One Weekday With No Wind Generation

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100 MwOutput

CAESGeneration to

Gridin Red

Grid Purchasesfor Compression

in Black

Length of Schedule Varied to Meet Market Needs.

Usually Not Scheduled on

Weekends.

Compressors Likely to Run 7 Nights a Week, Depending

Upon System Needs.

1.07 Tons of CO2 / Mwh

1.10 Tons of CO2 / Mwh for Lousia

December 5, 2001

Generation & Compression for 100 MW CAES Plant and 75 MW Wind Farm on Weekday

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CAESGeneration to

Gridin Red

0.21 Tons of CO2 / Mwh

Wind Generation Data from December 5, 2001

Wind Generation in Green


Why consider carbon costs?Because it is the right thingFuel diversification is needed to hedge cost of emissions – Keoto or not – a carbon tax or equivalent offset at $15/ton adds $17/MWH from coal vs. $4/MWH CAESOther emission reductions likely, e.g., SOx particulates, Mercury, others?


400,000 years of C02 and Temperature DataRecent Observed and Predicted Change

“Business as Usual”

2002

Doubling Scenario(550 PPM)

1800

2100

CO2

°C


Summary case for ISEPFor us, it is a local option for dealing with climate change. It keeps money in the state.Supported by customers

Very clean plant (local emissions)Uses Iowa’s most abundant indigenous energy resource, wind power, to mitigate GHG emissions

Supported by farmers who receive rents for wind turbines and for gas storage


Summary case for ISEPMeets need for intermediate generation with option for base load laterGood hedge against environmental costs for GHG and other emissionsDiversifies generation & fuel resourcesAdds renewable resourcesGas storage under further study


Where things standMunicipal utilities have spent about $800,000 to datePlant studies: Burns & McDonnell preliminary cost study complete, DOE-funded Black & Veatch market analysis complete and highly positive Underground Aquifer Storage: Site selection process well underway Transmission: initial studies complete; additional analysis to begin soon


DOE funded studies (initial $136,000 funding)

Independent verification of aquifer suitability Subcontractor: Fairchild & Wells, Inc. (Houston)Scope: Review of data from prior investigation of site as gas storage facility, subsequent well logs, ISEP seismic data, and other geological informationFinding: Adequate storage for CAES, though some reduction in previously estimated storage capacityStatus: Task complete


DOE funded studies (continued)

Assessment of suitability for two-gas storage Subcontractor: Fairchild & Wells, Inc. (Houston)Scope: Review of data from prior investigation of site as natural gas storage facility, subsequent well logs, AVO seismic data collected by ISEP, and other geological informationInitial finding: vertical communication between aquifers appears to limit two-gas optionStatus: Limited negative assessment complete



Power market forecast Subcontractor: Black & VeatchScope: Forecast of 20-year market clearing price for electricity in IowaStatus: Complete



Production cost modeling Subcontractor: Black & VeatchScope: Modeling of CAES plant marginal dispatch costs and operating constraintsStatus: Complete and very positive



Financial pro forma analysisSubcontractor: Black & VeatchScope: Pro forma analysis to determine return on investment, as measured by projected cash flows, net present value, and internal rate of return.Status: Complete and very positive


What’s next?DOE contracts for over $1.4 million in additional studies are nearly completeParticipants submitting letters of intentFind non-muni participants, if neededPlant start-up = 3 years from final approval

the iowa stored energy plant a project review and update may 2005 bob haug, executive director iowa...

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