I was listening to the April 26th
Peter Schiff Show hosted by Tom Woods. 
Tom played Senator Tom Carper’s suggestion of storing power from
windmill farms. He wanted to store the power produced from the windfarms in the
car batteries of the USPS vehicle fleet. 
This is laughable and akin to someone storing extra gasoline in zip lock
baggies in my opinion, but I will calculate out the rough number to humor
everyone.

Lets assume the wind stopped blowing
every morning at 3am.  So the vehicles at
3am would use their batteries to power the grid in lieu of the wind farms.

A car battery may have 75AH of capacity at 12 volts.  watts = volts x
amps. So 75 x12 = 900 watt/hours or .9 Kilo Watt Hours.

If you had a fleet of 100000 vehicles on the east coast you could store maybe 90,000 kwh of power. At 10cents per KWH this is 9,000 dollars worth of electrical storage capacity. 
$9,000 per day.  Lets see what it costs to do this.

The average car battery can withstand maybe 500 charge/discharge cycles at
best. We will estimate $100 per car battery replacement including labor.  This results in a cost of 20 cents per charge cycle in battery expense.  So we are up to $20,000 dollars in battery costs per day.

How much labor would it take per
night to hook and unhook the vehicles?

Let’s assume it took .5 manhours per
day to manage the program, hook up, and unhook the average 10 vehicles at each
USPS office. So .5 x 10,000 = 5000 man hours per day At the low hourly average rate of $24.37 this gives us $121,850 per day in labor costs.

How much equipment and infrastructure would it take to accomplish this feet?

We will estimate $20 in infrastructure and maintenance per year for the hardware to hook the vehicles to a dristro box at each USPS office.  And a cost of $1500 per year to setup each of 10,000 east coast offices with the equipment to put power back onto the grid and to track the power flow each way.  (1500*10000+20*100,000)/365

This calculates to $46,575 per day
in costs to enable Tom Carper’s idea. For the infrastructure component.

 
How much energy would be lost in the
transmission and conversion to and from 12v dc?

About 10% so our $9,000 revenue just
became $8100/day.

In conclusion.

Tom Carper would unwittingly cause
the government to spend $188,425 per day, so that we can store and release $8100
of electrical capacity per day.

Oh, and one more factor I almost forgot!

Opportunity cost of entire East coast
USPS fleet having dead batteries every morning… Priceless…

Aaaaah, somebody’s an engineer!!

I made this sort of an argument to some well meaning Greenie non-engineer once (female).
Needless to say I didn’t get lucky that night.