Tuesday, February 14, 2012

The Ultimate Fuel

Below is the best calculator I have come across comparing the cost of gasoline, utility supplied electricity and Solar PV.  It’s simple to use and you can customize the data inputs for your particular  area.  The picture is my scenario with our Solar PV cost and production,   You can clearly see that the system cost for a lifetime supply of the "Ultimate Fuel" is less than the cost of buying gasoline for three years.

click on image to enlarge

The BMW ActiveE when paired with renewable energy is an unbeatable combination of the “Ultimate Driving Machine”  and the “Ultimate Fuel”.   In many areas of the country, the Pacific Northwest as an example, the "Ultimate Fuel" is provided by hydro via the utility company at extremely low rates of $0.06 -$0.10 per kwh.   Pass go collect $200,  you live in the perfect plug in world.

For many of us in the more sunny states (thus less water for hydro) Solar PV makes great sense as a fuel for your ActiveE.    Renewable energy such as hydro, geothermal, wind and solar is simply the “Ultimate Fuel” for our light vehicle fleet whether provided by your utility or homegrown. The sooner we figure that out as a nation, the better off we will be, environmentally, socially and economically. 

Many thanks to  empulsebuyer for a great tool. Give the calculator a try, you might surprise yourself :)



  1. Peder, love the blog, love your writing - I've been reading for 3 years!
    However, I do think you are muddying your calculations a bit. Not that they aren't realistic, but they aren't a legitimate economic analysis of the options.
    By going EV, you have decided to consume 320 kWh's of electricity. Where you purchase those kWh's from has nothing to do with the price of gas - and to use gasoline cost to say that your payback period on solar is reduced is "Enron accounting".
    The actual payback on your solar is around 17 years. That's the point on your chart where the blue area finally reaches the black line representing PV cost.
    PV is a great option for a number of reasons - but it's not genuine to claim that powering a EV with PV will reduce the payback period to 3 years.

  2. Hi Chris,

    Thanks for reading. we can agree to disagree, I respect your point of view, perhaps you're right. I see you are referring to the cost of utility electricity as compared to solar when powering a car. In our case base line is 14 cents perkwh but when you get into the higher tiers it is 30 cents per kwh. Your point stands though as if you are a non solar SDG&E customer you can get the 14cents per kwh rate for your car. So either solar PV or utility supplied energy beats the price of gasoline by a large margin.

    For me, It's not Enron Accounting, it's the Norby family budget.

    Prior to our driving electric and powering by solar PV we were spending $4,800 a year for our home electricity (it's a large home that i don't pretend is as green as a small home) and $2700 a year for gasoilne.

    That $7500 expense is now $0-$300 a year driving electric and powering by solar. That savings combined give us a break even point of 5 years on our system cost. It would be about 7 years without the 30% fed tax credit.

    For the home its a 7-8 year payoff replacing utility electricity and for the car replacing gasoline it's a three year payoff for a combined 5 years.

    It may indeed be bad accounting practices but as i said it's our family budget and our experience.