Solar Powered Brammo by the Numbers

EmpulseBuyer’s Solar ROI Calculator

The beauty of an EV, like the Brammo Empulse or Enertia,  is that it will run on any fuel source that can be burned, or better yet harnessed, to create electricity. With a conventional auto, you are stuck with one finite source of energy.

I have seen many arguments about how EVs charge from “coal power” like its some kind of crime to burn domestically sourced fossil fuels rather than foreign sourced petroleum products. First of all lets take a look at how big a part coal actually plays in electricity generation in the US. According to statistics compiled by eia.govin 2011 coal comprised 42% of US electricity generation, less than half by a healthy margin. This number drops every year, while cleaner sources of energy increase every year. The fact is that EVs will always get cleaner as the grid evolves away from fossil fuels. The main point being that with an EV there are always options, in fact you can simply install a solar PV system essentially creating your own renewable and clean fuel. You cant drill for and refine your own oil out of your back yard but you can install solar panels on your home’s roof, or wherever direct sunlight is available.

Solar PV systems used to be relatively expensive, but in the last few years competition among other factors has brought prices down drastically. Add to that generous subsidies and rebates and solar PV system is a very worthwhile investment especially if there is an EV (Brammo) or two parked in your garage. Why is that? Consider the current price of gasoline is about $4 dollars a gallon, now with a properly sized solar PV system your electricity, in this case fuel, has essentially been paid for in full. That said, when you offset the price of gas with free fuel, your PV system and EV combo pays for itself that much faster for every mile you drive. This is compounded by the ever increasing price of gas and the fact that you are no longer subject to the whims of a relatively volatile market. Now that is energy independence!

To illustrate this pont, my modestly sized solar PV system is rated at 4.96kW and currently generates over a 1200 kWh surplus each year. Using Brammo’s proven combined range data of 77 miles, 50% City and 50% Highway, that 1200kWh will power a Brammo Empulse R for about 9240 miles every year. The cost to me, zero dollars and zero cents, unless you consider my initial investment for the PV system (~$9 thousand dollars). Compare that to a conventional motorcycle that gets about 35 mpg and I am saving over $1 thousand dollars a year:

(1200kWh / ~10kWh) * 77mi = 9240mi

(9240 / 35) * $4.00 = $1056.00

Considering my savings on utility bills and gasoline that I wont have to buy, my solar PV system will actually pay for itself in almost half the time with the help of an electric motorcycle.

Be sure to check out my recently updated Solar PV System ROI Calculator App. This app illustrates your return on investment (ROI) when combining a solar PV system with an EV, like the Brammo Empulse ;), while offsetting the price of gas.

  1. Karl says:

    Our 10kW system cost $70k before rebates and a 10% neighborhood group discount sales incentive from our installer. We’ve generated 9070 kWh in the first 5 months. I whole heartedly agree that scaling your PV system for a vehicle or more is the best way for anyone who has a reasonably long commute to green up and eventually see long term savings.

    Nice work scoring 5kW for $9k? Did you self install?

    I think Empulse might be two years out for me, because much of our nest egg went to solar this year. If the bike had been $14k minus $2500 in tax breaks, I might have swung it sooner. But that’s the retail price met the reality of running a business, and I hope setting a price with a profit will allow Brammo to live on past the investor phase. Everyone’s got to eat.

    • EmpulseBuyer says:

      $70k for 10kW… That sounds very high for a grid tied system. Is that a typo?

      The 5kW system we had bought for $9k is a result of generous Xcel Energy rebate and the federal 30% rebate. No self install, but we did buy the parts online, which I believe saved us even more money. We had a local company (Adobe Solar) do our install.

      The leases seem like a great deal. I have seen the Solar City truck a few places in our neighborhood already. From what I understand, you own them outright after 25 years, and before that point they are basically owned and maintained by the installer. That seems like a no brainer deal to me!

    • Anderlan says:

      Given $2/W currently for panels plus inverters, that means EB paid an additional 80% for installation hardware and labor, and you paid 250%. Unless you got yours when panels+inverters were at 3 or 4 $/W. When did you get your system? (You guys aren’t even mentioning rebates here, right?)

  2. Karl says:

    Also, while we chose to buy (I’m hoping s-recs become a reality in CA eventually and think that’s what lease holders are banking on) our installer said almost every install they do is a lease now, because it ends up being no money down and essentially locks folks at their current electricity cost, buffering them against increases, while still allowing them to go green. So if numbers like $9 and $70 sound freakishly unrealistic to you, don’t forget free solar is essentially in play right now if you act while incentives are still around.

  3. Nixon says:

    I would like to see a study of EV buyers to determine what the actual coal usage is. Because it seems like there are tons of folks who buy EV’s and PHEV’s who also talk about their solar installs, or other green electricity sources that they use to power their EV’s. My guess is that the approx. 40% coal number is in reality very highly inflated, because so many early EV buyers are finding ways to get their electricity from greener sources than just the grid average.

    One bad thing about Colorado’s rebates — it looks like you really have to buy your EV’s first, then install your solar. Because it looks like they cap how much solar you can install and get credits for based upon your current usage. (I think it is over the last 12 months, but I’m not sure about that). And it looks like it may be complicated to just expand your solar install. I’m still trying to figure out all of that.

  4. Andy says:

    I’m wondering why you guys sized your system so large? Are you having to completely recharge your battery. I have a relatively short commute, but estimated 20 miles or so a day w/ 4 hours of optimal sun coverage and only need like 500 W to offset my usage. That seems a lot more doable and realistic for local riding, unless you’re using the bike for a job or something.

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