ReTasking Spent Hybrid Vehicle Batteries as Peak Load

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

Motivation to Store Power Demand (MW) Marginal Cost ($/MW) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 In PJM, the Brattle Group determined that reducing the peak demand by 0. 9% dropped the market price of power 5 -8%. Gregory D Carlson University of Texas at Austin 20 November 2007

Power Storage Pumped Hydro Thermal Storage Compressed Air Grid Magnetic Storage Hydrogen Batteries Gregory D Carlson University of Texas at Austin 20 November 2007

Storage – Efficiency Source: http: //www. Electricity. Storage. org Gregory D Carlson University of Texas at Austin 20 November 2007

Storage – Costs Source: http: //www. Electricity. Storage. org Gregory D Carlson University of Texas at Austin 20 November 2007

Hybrid Vehicle Batteries - Prius n n n n Chemical Composition - Ni. MH Capacity – 6. 5 Ah, 201. 6 V (1. 95 k. Wh) Size - 0. 02 cubic feet Weight – 99 lbs Modules - 28 Useable Life – 1500 -2000 cycles in vehicle usage (translates to 6 -12 years) Cost – Almost free since they are being discarded Gregory D Carlson University of Texas at Austin 20 November 2007

Pros/Cons of Hybrid Ni. MH n Pros ¡ ¡ ¡ n Cheap Point of Use High number (failure is probabilistic) Small size (relatively) No additional land requirement Gregory D Carlson Cons ¡ ¡ University of Texas at Austin No clear vendor Not very efficient (50 -70%) 20 November 2007

PHEV – EV Projections n n n Over 600, 000 hyrbids in US right now Hybrid market share is increasing EV/PHEV battery size versus HEV ¡ n EV and PHEV battery packs will be similar chemical composition initially, but much larger Next Gen Batteries – Li-Ion vs Ni. MH ¡ Li-Ion have higher energy density, but lower life expectancy – may not be good for this application Gregory D Carlson University of Texas at Austin 20 November 2007

References n n n n “Quantifying Demand Response Benefits in PJM, ” Brattle, 2007. “Potential for DR, EE, and Onsite RE to Meet Texas’ Growing Need, ” ACEEE 2007. http: //photography 4 therestofus. wordpress. com/batteries/ http: //batterydata. com/ http: //www. toyota. com http: //science. howstuffworks. com/question 247. htm http: //auto. howstuffworks. com/question 219. htm http: //en. wikipedia. org/wiki/Grid_energy_storage Gregory D Carlson University of Texas at Austin 20 November 2007