Hydrogen to electricity?

Here’s a good candidate for the silliest energy idea I’ve heard in a while: http://www.ted.com/index.php/talks/reinventing_the_car.html Larry Burns, the vice president for R&D; at GM, notes that 4% of cars equal the power generation ability of the entire current electric grid, and dreams of a future where fuel cell vehicles are used to generate electricity while parked. This is great because hydrogen can come from a wide variety of sources, so as long as each community has their own tailor-made method for generating it, we can use the cars to cheaply generate electricity.