Barium-titanate ultracaps.2007, MIT Technology Review:
A new ultracapacitor technology by EEStor is claimed to store 10x the power of a lead-acide battery at half the cost and is superior in terms of energy density, price, charge time and safety. Ultracaps, as they are sometimes called, can store and release energy an almost unlimited number of times, or more times than current rechargable batteries anyway. It uses barium-titanate powders.
Energy cost comparison to drive 500 miles:
- Gasoline: $60
- New EESU ultracap: $9
Bloom energy cellGoogle has been testing the Bloom Energy cell which takes natural gas (and oxygen from the air) as input. Google has been testing it since 2008. The BEC does not use combustion to create energy. It's being tested by other large companies all over the world like Johnson and Johnson, AT&T, Nokia, Bank of America, Caltech, Adobe, Dreamworks, Ebay, Honda and Panasonic.
An "energy cell" can be combined into an "energy stack", and these can be combined into an "energy server". Energy servers are installed onsite so electricity doesn't have far to travel in order to be used.
Here's model UMP-571, which weights 5000 lbs and outputs 200kw at 480vac. It seems a bit big for home use as US homes take 120vac.