Evaluating Ultracapacitors for the Saturn Vue Mild Hybrid Platform: Cooperative Research and Development Final Report, CRADA Number CRD-08-00276

Recent analysis conducted by NREL for the USABC and the Electrochemical Energy Storage Technical Team indicated that HEVs utilizing smaller energy windows from the on-board storage system can achieve much of the fuel economy benefit realized by larger energy window HEVs. The simulations showed that nearly all hybridization fuel savings are realized with energy windows of 150 Wh or less.Dynamometer testing of a variety of production HEVs (both mild and full hybrid) has confirmed battery window use less than 200 Wh on standard drive cycles. These findings suggest a cost-saving opportunity from using either smaller batteries or ultracapacitors (which have lower projected long-term costs and superior cold-temperature performance) in order to still achieve a sizeable hybridizationbenefit.