The hydraulic hybrid, is going to kill the electric car. Hydraulic accumulators can store 500 kW/kg, the best and very expensive, battery technology today can store 3 kW/kg, hydraulic has 166.67 times the storage capacity batteries. An electric car that has 100 mile range with batteries would have 16,667 mile range with the same weight of hydraulic storage.
http://www.designnews.com/article/CA6549294.html
Philip