I believe that you're thinking of LANL's "Green Freedom" concept: http://bioage.typepad.com/greencarcongress/docs/greenfreedom.pdf http://bioage.typepad.com/gr

I believe that you're thinking of LANL's "Green Freedom" concept: http://bioage.typepad.com/greencarcongress/docs/greenfreedom.pdf http://bioage.typepad.com/greencarcongress/docs/greenfreedom... They estimated that it required a pump price of $4.60/gallon for gasoline to be economically viable, given their other assumptions. The authors assumed relatively low cost nuclear power from Generation III reactors. But the Green Freedom concept seems like it would also work with sufficiently cheap large scale renewable electricity production.