A more likely scenario is that all those figures are doubled: 20 HP -> 15 kW-hr per hour of operation.
At California’s 2010 average residential electricity rate of 15 cents per kW-hr. this is then about $2.25 per hour of operation.
Not a bad deal, actually.
Only if you are the only one in your area with one. Wait until every tree hugger in the neighbourhood is charging.
Also, the state and Feds will find a way to make up for the drop in fuel tax revenue (Think “seperate meter for your car charging station with a special electric car rate per kW Hour.”).
746 watts = 1 Hp.
Battery chargers are less then 65% efficient due to poor
power factor and harmonic distortion.
Batteries are not 100% electrochemical converters.
More on the order of 60% - 70%.
That's why they get so damn hot when you charge them.
You can not put 1kw into a battery and get 1kw
out. Not never.
Electrical distribution losses from the grid to the
chargers can easily be 8%.
High power chargers will have 3 - 5 % power loss just
in local wiring alone.
Traction Inverters tend to be around 85 -90 % efficient.
Add it up.
Carnot's law will not be broken.
Wait until they start to charge everyone for the higher transformer failure rate!
"The other half of the equation, today’s local electric distribution system, probably wouldn’t be able to cope with a nation of newly purchased EVs all driving home from work and plugging in during peak demand hours. Why? Take the transformer or power pole near your home, for example. That transformer may serve 4 to 6 homes and have very little reserve capacity for reliable operation when additional demand (like charging electric vehicles) is added. Each electric vehicle roughly doubles each homes’ peak power demand, so if everyone buys an electric car we’re either going to need bigger local transformers, or more of them. Additionally, round-the-clock demand prevents the transformers from cooling down at night, something which could result in premature transformer failures and local blackouts".
http://www.beyondthelightswitch.com/blog/electric-vehicles