Solar Grand Plan: The Role of Energy Storage James Mason Renewable Energy Research Institute Presentation for ISA Expo Houston, TX – 6 October 2009

Solar Grand Plan: Components Wind Power Plants in Midwest U.S. 1) Energy Storage a. Compressed Air i. Thermal for Compressed Air Solar Power Plants in Southwest U.S. 1) Photovoltaics (PV) & Solar Thermal 2) Energy Storage a. Compressed Air and Thermal National HVDC Transmission System Electric Vehicles 1) Fuel Cell and Plug-in Hybrid 2) National Fueling Infrastructure Using Renewable Fuel Sources a. Electrolytic H2 and/or Electricity Geothermal Cellulosic Biomass

Solar Grand Plan Costs 1.Base Load Retail Electricity Price = $ /kWh. Peak Retail Electricity Price = $ /kWh. 2.Total Capital Investment to 2050 = $16 trillion. Is This Cost Too Great? * Consider 2008 U.S. Oil and Natural Gas Drilling Costs from EIA Well Cost Data (2004 $; billion $) Oil = $28b; Natural Gas = $64b; Dry Wells = $24b Total 2008 U.S. Drilling Costs = $105b * Domestic Oil and Natural Gas Drilling Costs Alone Easily Could Be As Much As $10 trillion by 2050.

Benefits of Solar Grand Plan Stabilization of Long-term Electricity Prices. – While Capital Costs Are High, Fuel Cost Is Free. A doubling of natural gas and coal prices will result in cost competitive solar and wind electricity rates. Increases U.S. Energy Security. Is a Safe and Sure Means to End Carbon Dioxide Emissions. Creates a Significant Increase in Energy Efficiency. Creates Jobs and Economic Growth.

Next Steps on Path to the Solar Grand Plan 1.Transform Intermittent Wind into Dispatchable Load Capacity by Coupling Wind Plants to Compressed Air Energy Storage (CAES) Plants in Midwest. Need to Include CAES in Fed/State Renewable Energy Incentive Rules and Regulations. 2.Develop Low Cost Thermal Energy Storage (TES) Systems: * One-Tank, Thermocline, Thermal Energy Storage Systems for Concentrating Solar Thermal Plants * Compressed Air Heat Capture and Storage System for CAES. 3.Comparative Research of Fuel Infrastructure Design and Costs for Plug-In Hybrid and Fuel Cell Vehicle Pathways, which Includes Evaluation of Public Driving Preferences.

The Solution to Wind and PV Intermittency: Compressed Air Energy Storage (CAES) Alabama Electric Cooperative’s McIntosh, Alabama 110 MW CAES Power Plant in Continuous Operation Since 1991

CAES Air Turbine Power Plant

A Coupled PV-CAES Plant for Peak Load Capacity

Next CAES Plant Will Be Similar In Design to the Schematic Adiabatic CAES (No Natural Gas) Will Not Be Available Until Post-2020 * Wind/PV Electricity for Air Compression Conventional CAES = 0.8 kWh In / kWh Out Adiabatic CAES (No Natural Gas) = 1.43 kWh In / kWh Out * CAES Plant Natural Gas Consumption Conventional CAES = 4,800 Btu (HHV) / kWh Out Fuel Efficiency of a Coupled PV-CAES “Peak” Power Plant Aggregate Electricity Supplied to Grid = 64% PV and 36% CAES Aggregate PV-CAES Fuel Efficiency = 191% (3,412 Btu / 1,786 Btu) * Conclusion: Coupled Wind/PV CAES Is Dispatchable Load Capacity, Improves Grid Reliability, and Significantly Reduces Fuel Consumption and CO2 Emissions CAES – Compressed Air Energy Storage Power Plant

Existing Underground Natural Gas Storage Sites

Solar Thermal Power Plant with a One-Tank Thermocline Thermal Storage System (Future) Solar Collector Field Thermal Storage Tank (Molten Salt ? Steam Electricity Generator

Immediate Needs 1.Define CAES in Renewable Energy Incentives. - In Fed/State Legislatures and Regulatory Agencies. 2.Federal Support to Design/Build a HVDC Grid to Distribute Midwest Wind and Southwest Solar Electricity Nationwide. 3.Create a 10-Year Feed-In Tariff Program to Support the Development of Wind & Solar Energy Storage Power Plants. 4.Development of Automated Systems to Synchronize the Supply Route of Wind, PV, and CAES Electricity Production.

Conclusion Development of Low Cost ($12-15/kWt) Thermal Energy Storage is Essential for Solar and Wind to Become Sources of Dispatchable, Zero CO2 Emissions Power and Fully Capable of Replacing Both Base and Peak Load Fossil Fuel Power Plants. With Dispatchable Solar and Wind Power Plants, We Can Stabilize Long-Term Electricity Prices and Be Approaching Zero Energy Related CO2 Emissions by 2050.

Acknowledgements Bill “Burr in the Saddle” Bailey – Fiscal Associates Ken Zweibel – George Washington University Vasilis Fthenakis – Columbia University and Brookhaven National Lab