Solar as EV ‘gas’ can pay more than feed-in tariffs


editors-blog-entry3We’ve had our 5.59 kW home solar system for a little over four months now and we’ve already saved nearly $1,500 worth of “gasoline” for use for a future electric car — at least if you calculate this according to the following formula:

  • 1 kWh = 4 miles (our current extra kWh total = 2,473 kWh)
  • 20 m.p.g./ $3 per gallon gas

Obviously, if you increase the miles per gallon rate, the savings drop. So, too, if you decrease the per gallon gasoline cost.

Similarly – and this is more interesting, because gasoline prices are unlikely to drop significantly in the U.S., where they are already very low – if you calculate a higher per gallon gasoline cost, the savings go up.

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The U.S. has ridiculously low gasoline prices in comparison to much of the industrialized world. This is because its gasoline taxes are the second lowest among leading industrialized nations, accounting for 17 percent of the total cost of a gallon of gasoline. Compare that to 63 percent in The Netherlands, or 62 percent in Norway, where gasoline is around $6 per gallon!

What if we lived in Europe?
So, what if we lived in The Netherlands, Norway, or another European country with per gallon gasoline costs of around $6 rather than $3 – how much auto fuel savings would we have generated in the past four months?

Here are a couple of different looks at this question using different miles per gallon figures, but using the same 1/kWh = 4 miles x 2,500 kWh figures–>

  • 20 m.p.g./$6 per gallon = $3,000 worth of fuel saved
  • 25 m.p.g./$6 per gallon = $2,400 worth fuel saved
  • 35 m.p.g./$6 per gallon = $1714 worth of fuel saved
  • 50 m.p.g./$6 per gallon = $1,200 worth of fuel saved

If you live in Europe and you’re in position to put solar panels up your own private property, you might want to take a look at the numbers here — though, of course, you’ll want to do it in liters. (Sorry, while I believe the entire world should adopt the metric system, I still don’t think in metric terms).

Of course, in many places in Europe, for instance, Germany, solar producers are paid an excellent, though also diminishing, feed-in tariff rate for the kWh their solar system produces.

The latest per kWh feed-in tariff figures I could find for new, smaller, residential systems in Germany peg it at 46 cents per kWh. At this rate, the 2,500 extra kWh we’ve produced would garner $1,150.

That’s considerably less than the $3,000 of gasoline savings calculated at 20 m.p.g./$6 per gallon. Of course, it’s about the same as the gasoline savings that 2,500 kWh produce at 50 m.p.g./$6 per gallon.

Feed-in tariffs vs. EV+PV
Let’s bring things back to the United States, more specifically to Oregon, where some lucky customers of Portland General Electric, Pacific Power and Idaho Power, recently locked in feed-in tariff per kWh rates of up to 65 cents. Since we’re back in the U.S., we’ll need to drop our per gallon gasoline costs to those ridiculously low per gallon price of about $3 per gallon.

Let’s crunch comparative numbers through the lens of 20 m.p.g. and $3 per gallon:

  • Feed-in tariff –> .65 per kWh x 2,500 kWh = $1,625
  • Home solar fueling –> 20 m.p.g/$3 per gallon, 1 kWh/4 miles x 2,500 kWh = $1,500

money-sign-panel-vert1The feed-in tariff wins in this case, although, to be fair, the bigger picture is actually more complicated than the numbers you see here. You’d have to add in utility rebates, tax credits, etc. on the two solar systems – the feed-in tariff system vs. the non-feed-in tariff system — to get a better sense of this.

EV+PV pays off
In the end, even though the numbers vary significantly based on m.p.g. rates and per gallon costs of gasoline, producing extra kWh and using them to power an EV and replace gasoline is generally a good to outstanding financial move comparable, in terms of savings/money generated, to what you would generate under a feed-in tariff situation.

Having amassed $1,500 worth of “gasoline” savings in about four months with a per gallon rate of $3, EV+PV has certainly proven to be an outstanding financial move for us (we’ll reach solar payback on our 5.59 kW in less than three years; in fact, depending on how much we decide to heat our home with electric, we could achieve solar payback in about two years!) .

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Of course, it would be even better if gasoline were $6 per gallon which, of course, it is in The Netherlands, Norway and other parts of Europe.

Maybe we should move our solar operations overseas 😉

Then again, maybe not: We’ve got a lot more sun here in Colorado than in Northern Europe.

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