Charts for Cost of Solar Fuel

I have received a good number of off line emails asking me how I arrived at the incredibly low cost per gallon equivalents for an electric car powered by solar. As a basis for comparison, I used the average miles traveled by a car in the U.S. and the average fuel economy for cars and SUV's in the U.S.

below are some charts which I hope will help explain. (Hint, if you click on the charts they enlarge)



The above graph is the cost of fuel paying cash for driving a 20 mpg gasoline car for 12,000 miles a year. Fuel cost is $3.00 a gallon increasing at 5% a year. This increase is historically the same increase as the last 25 years from 1985 to 2010.


This next chart is the cost of solar fuel if you were to pay cash. Of note is that the total cost of the system is equal to 4.25 years of paying fuel cost in the 20mpg gasoline car.

The Mini-E gets 3.50 miles per KWH. To drive 12,000 miles a year on solar energy I need to generate 3500kwh. In Southern California that is a 2kw Solar PV. System. My install that I did 4 months ago came out to a net cost after fed tax credit of $4,000 per kw or $8000 for a 2kw system. This is roughly the system cost estimate from b.p. solar as well.
Assumed is a $2200 inverter replacement at year 12.


This next chart is the cost of solar fuel if you were to finance the purchase on a PACE (Property Assessed Clean Energy) program.

The Mini-E gets 3.50 miles per KWH. To drive 12,000 miles a year on solar energy I need to generate 3500kwh. In Southern California that is a 2kw Solar PV. System. My install that I did 4 months ago came out to a net cost after fed tax credit of $4,000 per kw or $8000 for a 2kw system. This is roughly the system cost estimate from b.p. solar as well.

Conclusion:

I am only comparing the cost of fuel vs. the cost of solar energy. No attempt is made to account for the cost of batteries whether they are life of vehicle or need to be replaced every 7 years. Nor is an attempt made to calculate the cost of replacement engines, transmissions, brake jobs, tune ups and other cost associated with a gas car.

Your results will vary depending on your sunshine profile and where you are located as system cost can vary by location. But if you're in the sunshine belt the above graphs should come very close for most people.

On a KWH generation basis Solar is essential 1/8th the cost of gas for me to drive for the next 25 years+. This equals $0.38 cents a gallon of gas equivalent. It is also a fixed price and protects me against spikes and inflation.

On a cost basis solar is $0.20 cents a gallon of gas equivalent as I only need to generate 1750kwh at peak time (30 cents per KHW) to pay for the usage of 3500kwh of off peak charging (14 cents per KWH)

That's my world, that's my real world experience.

Cheers
Peder