Combustion engines are about 15-20% efficient. Toyota has 30+% engines in their Prius.
Electric motors are about 90% efficient.
So electric motors are about 5x more efficient than ICEs.
Electric motors are about 90% efficient.
So electric motors are about 5x more efficient than ICEs.
https://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3
Efficiency of coal plant is ~ 33%
http://www.eia.gov/electricity/annual/html/epa_08_01.html
Natural gas is about ~40%.
So in reality you are getting 90% of ~35% or 31.5%.
So to charge a 90kwh battery, you need roughly 99kwh of energy.
Which for me, since it's charging in my garage, the excess heat is actually kind of nice as it will keep my garage slightly warmer in the winter and thus my house as my garage is on the lower floor.
Either way, it's still WAY more efficient than any time of combustion engine. Including hydrogen. Hydrogen is kind of a wasted effort (unless we are doing fusion ;p )