Monday, June 15, 2009

The High Cost of Cheap Oil

Loving the Mini-E, every mile of it.

Driving with electrons prompted me to write a little about our energy rate structure and the comparison between gas and electric.

Our rate program with SDG&E is ev-tou2. This rate structure is around 16 cents kwh between midnight and 7am and then during the peak periods of the day it's 32 cents kwh.

What that means for us is that for every kilowatt of energy I generate during the day I get to use two in the early morning hours for the same price to fuel the Mini-E

If the car needs 10kwh to charge at night, I need to generate just 5kwh during the day to be cost neutral.

My experience to date (515 miles in #183) is about 3.25 miles per kwh. 8kwh gives me a range of 26 miles, about the same that a regular mini would get real world out of a gallon of gas.

A 1.1kwh solar p.v. system generates 1850 peak KWH . This generation would equal the cost for the 3700kw off peak usage of the Mini-E on an annual 12,000 mile basis.

If I am conservative and expect just 25 years of life for the solar P.V., the math looks like this:

Gas Mini,

12,000 miles 26mpg at $3,50 a gallon of gas= $1650 per year
25 years of driving, $41,250 (assumes zero price change)
with 8% annual escalator $120,613

Yearly average $4824 for gas


Electric powered Mini-E.

12,000 miles, 3.25 kwh per mile is 3700 kwhs @.16cents = $592
25 years of driving, $14,800 (assumes zero price change)
with 8% annual escalator $ $43,256

Yearly average $1730 for electricity


Solar electric powered Mini-E

12,000 miles, 3.25kw per mile you need to generate 1850 kwhs annually at peak hours to pay for 3700kwhs used at off peak. This is a 1.1 kwh solar pv system at a cost of $5500.
25 years of driving, $5,500 (guarentees no price change)
no escalation as the sun does not raise it's prices

Yearly average $220 for Solar P.V electricity



Cost of fuel over 25 years:

Gas is 300% as expensive as utility purchased electricity

Homeowner generated solar is less than 5% of the cost of Gas.

Most of us will be driving for at least 25 years.

A 1.1. kw Solar P.V. system purchase cost is the equivilent to purchasing gas for$3.50 per gallon for 3.25 years


1 comment:

  1. Fantastic post Peder, I love the numbers. Solar + EV = Perfection in SoCal!