Electric Cars for Commuting

While I doubt I'll be able to afford one until long after they become available, I'm anxiously awaiting the release of some (almost) pure electric cars. The Chevy (GM) Volt is of particular interest, as it seems to be one of the front runners at this point. It seems that the battery technology is the real weak point at the moment.

From their site:
"All the technology for the car is here today, except for the battery pack. It will use lithium-ion (li-ion) technology. Current hybrids use nickel-metal hydride (NiMh), which carry much less energy per unit weight. The li-ion cell technology exists but putting it into tested and safe packs is what will take some time. There are companies working with GM and trying to get these Li-ion batteries and their packs ready for automotive use."

It's fascinating the different energy storage technologies that have been tried. I recall a city bus that used a large flywheel to recover energy (using regenerative braking) and store it to start the bus back up after each stop. Certainly NiMh batteries see a lot of use in hybrids today, but aren't ideal. Supercapacitors have pretty decent energy storage capacity, but unfortunately petroleum based fuels carry about 100 times the energy (per kg of mass - about 12 kWh vs. 0.12 kWh for Lithium Ion batteries).

Fundamentally, hydrogen is a nice way to store energy, but because it doesn't exist in nature (most of the hydrogen on earth exists in the form of water, H2O) we can only create hydrogen "fuel" by using another energy source to break down water (or some other source of hydrogen, like natural gas). I have only looked briefly at this site, but it seems to have a decent rundown of the requirements to create some amazing solar projects in the southwestern USA.

I'm sure there's some great research going on to find more efficient (and cost-effective) ways to convert solar and other energy forms into hydrogen, because solar (on it's own) isn't a solution to our energy problems. The reason for this is simple: the sun sets at night and peak demand occurs late in the afternoon and into the early evening. For the same reason that electric cars have limited range, we can't store enough energy (with current technology) to keep everything running overnight. If a highly efficient solar-to-hydrogen conversion system can be developed, then storage becomes much easier.