1. Re-Tasking Spent Hybrid Vehicle Batteries as Peak Load Shavers Gregory D Carlson Energy and Earth Resources Jackson School of Geosciences University of Texas at Austin

2. Gregory D Carlson20 November 2007University of Texas at Austin 23000102030405060708091011121314151617181920212224 Demand (MW) Marginal Cost ($/MW) Motivation to Store Power In PJM, the Brattle Group determined that reducing the peak demand by 0.9% dropped the market price of power 5-8%.

3. Gregory D Carlson20 November 2007University of Texas at Austin Power Storage Grid Pumped Hydro Compressed Air Magnetic Storage BatteriesHydrogen Thermal Storage

4. Gregory D Carlson20 November 2007University of Texas at Austin Storage – Efficiency Source: http://www.ElectricityStorage.org

5. Gregory D Carlson20 November 2007University of Texas at Austin Storage – Costs Source: http://www.ElectricityStorage.org

6. Gregory D Carlson20 November 2007University of Texas at Austin Hybrid Vehicle Batteries - Prius Chemical Composition - NiMH Capacity – 6.5 Ah, 201.6 V (1.95kWh) Size - 0.02 cubic feet Weight – 99lbs Modules - 28 Useable Life – 1500-2000 cycles in vehicle usage (translates to 6-12 years) Cost – Almost free since they are being discarded

7. Gregory D Carlson20 November 2007University of Texas at Austin Pros/Cons of Hybrid NiMH Pros  Cheap  Point of Use  High number (failure is probabilistic)  Small size (relatively)  No additional land requirement Cons  No clear vendor  Not very efficient (50-70%)

8. Gregory D Carlson20 November 2007University of Texas at Austin PHEV – HEV – EV Projections Over 600,000 hyrbids in US right now Hybrid market share is increasing EV/PHEV battery size versus HEV  EV and PHEV battery packs will be similar chemical composition initially, but much larger Next Gen Batteries – Li-Ion vs NiMH  Li-Ion have higher energy density, but lower life expectancy – may not be good for this application

9. Gregory D Carlson20 November 2007University of Texas at Austin References “Quantifying Demand Response Benefits in PJM,” Brattle, 2007. “Potential for DR, EE, and Onsite RE to Meet Texas’ Growing Need,” ACEEE 2007. http://photography4therestofus.wordpress.com/batteries/ http://batterydata.com/ http://www.toyota.com http://science.howstuffworks.com/question247.htm http://auto.howstuffworks.com/question219.htm http://en.wikipedia.org/wiki/Grid_energy_storage