Battery Powered Vehicles, The Future??

[Murphyv310]

This http://large.stanford.edu/courses/2010/ph240/eason2/ is a fairly good analysis on global lithium production, accessible reserves, and how many Nissan Leaf's you could build from those. The numbers do not stack up, alas.

The Leaf has a 24kWh (24e3 x 3600 = 86MJ) battery and that gets you 300 miles if driven conservatively. Annual mileage is say 12,000 miles, or about 1 recharge per week. There are 32 million domestic cars in the UK, so it would take 86e6 x 32e6 = 2.7e15J per week to charge them. Double that for energy losses in distribution, power conversion efficiency in the charger, and battery charge efficiency and get to 5.4e15J per week of generation capacity.

Divide by the number of seconds in the week (6e5) to get generation power of 9GW. Current grid capacity is 45GW, which we use completely during the Winter.. So to deal with a complete electrification of domestic cars with Nissan Leafs would take a 20% increase in electricity generation capacity. If everyone owned a Tesla (I wish!) with an 85kWh battery we would need to almost double the energy generation capacity to charge them.

And none of those estimates takes account of commercial vehicles.

So although the aim to reduce vehicle emissions to zero is laudable, the practicalities (at this point) just don't stack up.

OK I hear you say - fuel cells. The energy equation still stands though. There is a similar energy cost associated with production of hydrogen-rich fuels. There is alas no escape from the conundrum.

Craig

Ah but.
What about the electricity used at present in oil refineries, you need to factor that into the equation too.