I’ve written quite a bit about how solar-charged driving can save you money.
But the truth of the matter is whether solar-charged driving will save you money is that it depends.
It depends on a number of crucial factors. Among them:
- solar costs and rebates (or lack thereof) where you live;
- electric car rebates (or lack thereof) in your country (not everyone’s lives in the U.S.!), or in your state;
- the point of comparison between solar-charged driving, or just electric driving, and gas-powered driving– I’ll explain this below.
The short version of our story below is that solar-charged driving will not save us money, at least not in the short term.
Here’s why:
We’re currently driving two old gasoline cars: A 1992 Acura Integra with 150,000 miles on it, which I bought new 19 years ago, and a 1994 Toyota Camry with 275,000 miles on it, which we inherited from my brother for $1 about 3 ½ years ago.
No car payments for a decade
Basically, we have not had a monthly car payment for more than a decade.
Adding a brand new EV to the home stable is going to change that – in a big way.
Yes, we do have maintenance costs associated with our two “clunkers”. However, because our Integra and Camry have both been treated well, these costs are relatively low. Right now about $1,200 per year for both vehicles (this is a rough average across the past three years).
That’s about $120 per month for two vehicles. That’s a helluva lot less than monthly payments for any type of brand new vehicle, whether you’re talking about a gas-puffing Honda Fit, or a solar-charged Nissan LEAF or Ford Focus Electric.
OK, we do have to add our gasoline costs to the equation. We put about 7,500 miles on each of our gasoline cars per year, or 15,000 miles between the two of them. They average roughly 25 mpg each and we’re paying about $3.85 per gallon for gas right now in Colorado (we buy high octane gas).
So, let’s say we spend about $2,300 per year on gasoline. Then, we’re looking at $3,500 per year to run two cars – total.
That’s pretty damn cheap.
EV + PV equation
There’s no way we’re going to beat that with our EV + PV equation.
This, even though out of pocket costs for our 5.59 kW solar system were just $8,000, and this despite the fact that by the end of our first full year with solar we will have banked 5,000 kWh of system over-production with our utility, Xcel Energy, or the equivalent of about $2,700 worth of “gasoline” (25 mpg, $3.85 per gallon).
Keeping the equation simple and perhaps a bit unrealistic by not including any sort of inflation/increase in costs for our current “clunker” two-car gas combo, not including interest for a loan for a new EV, etc. and taking a five-year snapshot, here’s what we’re looking at:
- 5-year cost for our two gas clunkers: $3,500 x 5 = $17,500
- 5-year cost for one solar-charged EV (Nissan LEAF) = $20,200 (post rebates EV) + $8,000 (post rebates 5.59 kW solar system) + $600 (post rebates home charging station) = $28,820
In fact, the equation is more complicated than the one I’ve drawn here, as we’ve already paid off our solar system (we paid cash for it). But we won’t completely recoup our $8,000 until about three years from the day we bought it.
Quick solar payback
That quick payback time (two to three times the average rate) is due the fact that we’ll be using our PV generated electricity to replace gasoline and power an EV.
That’s totally cool.
But it doesn’t change the fact that based on the admittedly incomplete analysis I’ve done here, EV + PV does not come out on top in our two gas clunkers vs. one new EV + home solar system scenario, at least not when looking at a five-year snapshot.
If you push things out longer, say, to six years, the cost for the two gas clunkers, $21,000, equals about the cost of a new Nissan LEAF (with U.S. and Colorado rebates). Sort of – again, I’m not including the interest costs on a loan for a new LEAF.
Of course, we’re talking about two gasoline cars vs. one new electric car.
Two new plug-ins expensive
Throw in a second electric car, which, for us, would need to be a plug-in hybrid like a Chevy Volt, and which would cost us about $25,000 after U.S. and Colorado rebates, and you’re looking at about $47,000 for the two new EVs alone.
Add in $8,000 for the 5.59 kW solar system, and you’re up to $55,000, again, not including interest costs on car loans, sales tax costs, etc.
The bottom line: Solar-charged driving most likely will NOT save you money, even over an extended period of time IF you’re talking about a used/old gasoline car(s) vs. new electric car(s) comparison.
It would take more than 15 years with our two gas clunkers before we hit $55,000 in costs.
But, that’s assuming:
a) gas prices are the same 15 years from now (anyone willing to take THAT bet?);
b) our 17-year-old and 19-year-old clunkers will run another 15 years (an only slightly better bet than gas prices being the same 15 years from now).
Ok, let’s complicate this further – and then we’ll stop and let better math brains take over in the comments field 😉
Let’s assume we can count our solar system costs as $0 after we hit the three year mark and that we’ll produce $2,700 worth of “gasoline” every year for the next 10 years after that (again, we’re assuming NO rise in the price of gas, which is unlikely to occur). That’s $27,000 worth of fuel, or, basically, enough to power two electric cars for 10 years, meaning $0 in auto fueling costs for us over those 10 years.
Again, though, we would have had to spend $47,000 to buy a new LEAF and Volt (the latter of which we’d have to fill with gas, I’m guessing, about six to eight times a year).
EV battery replacement
Then there’s the EV battery equation: Battery replacement is likely for the LEAF after about 10 years. That’s likely a several thousand dollar investment.
On top of that, there are the replacement costs for our solar inverter, which will probably die at about 13 years, to the tune of several thousand dollars (sure wish we had those 25-year Enphase micro-inverter systems now 😉
The bottom line: Solar-charged driving most likely will NOT save you money, even over an extended period of time IF you’re talking about a used/old gasoline car(s) vs. new electric car(s) comparison.
And this just so happens to be our point of comparison, as “apples to oranges” as it might seem to some.
HOWEVER, if you compare brand new gasoline cars to brand new EVs and you live in an EV and solar friendly state such as Colorado, California, Oregon, etc., there’s a good chance you will save money by plugging into solar-charged driving starting as early as the third year you have your PV system and your EV(s).
Used EVs?
This picture might eventually change as the possibility of buying used EVs becomes a widespread one (this will take awhile) and gasoline prices rise substantially in the U.S., to, say, $6 or $7 per gallon.
Until then, living with a good but also relatively old gasoline car that also happens to get decent mileage, as both our ’92 Integra and ’94 Camry do, is almost certainly going to be cheaper than solar-charging a brand new EV. In fact, owning a well-maintained, fuel-efficient gas “clunker” that’s already been paid off is also almost certainly going to be cheaper than owning a new EV, no matter how you end up fueling your EV.
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This is the basic reality of the comparatively high cost of brand new production EVs as opposed to the much lower cost of older and/or used gasoline cars in decent shape and which get decent mileage.
That might be discouraging to some – and, frankly, it is a little bit to me.
But it doesn’t have to be. Solar-charged driving still offers substantial environmental benefits. Just as important are its independence advantages. These include the most satisfying independence benefit imaginable: Being able to flip Big Oil the bird — once and for all!
Now if that’s not worth a few extra bucks, I don’t know what is 😉
Related articles–>
- How much does solar-charged driving cost: Two scenarios
- Extra solar production = future gasoline savings
- Solar before the EV the way to go for many
- Re-doing the solar math on the Nissan LEAF
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