The current issue of Bloomberg Business Week has an article "Storing Power in Molten Aluminum Lakes" which describes how a German aluminum producer (which uses huge amounts of electricity) can serve as a power buffer and storage system. When power is available (at times it is almost free when sun and wind produce lots of renewable electricity), the plant runs at full production. When power is needed, the electrolytic process can be run in reverse and the huge aluminum "battery" can provide power. Eventually the plant expects to be able to store enough power in 2 days to power 300,000 homes for a day if the need arises!
I hope that I am not totally off-base to receommend NOT calling the current crop of EVs "green vehicles".
They may be "greenER vehicles" but they are certainly NOT green in any sense of the word "green" which denotes environmentally safe. Recent news about Toyota wanting to change course and concentrate more on hydrogen-based power cells (vis-a-vis Prius hybrids) appear to be more correctly aligned with dreams of the tree-huggers and I am not using those two words in a pejorative way.
I hope that the current research on graphene-based supercaps are more green than Li-Ion based batteries for the "long haul".
Yes! I am waiting for that development where the EVs run on lighter batteries and Supercaps that give a fast accelaration and regenerative energy storage.
If if these batteries can get charged by the solar panels mounted on Car-tops, it all the more beneficial.
So the challenge today is to combine three technologies - Graphe like materila for batteries , The SuperCaps and the Solar panels with lighter and more efficient material. to get a real boost for EVs of tomorrow.