Solar Charging An Electric Vehicle

Ah, the lure of the electric vehicle. What’s not to like? Amazing driving experience and emissions free. Best of all, you will pay about $500 per year on electrons instead of over $2,000 per year on gasoline. And feel true exhilaration as gas stations, and gas prices, rush past you.

Not So Fast…

By purchasing an EV, you’ve just added as much as 30% to your home’s electricity consumption*, and that extra 3,700 KWh of electrical energy per year has to come from somewhere.

  • It could be supplied by controversial new hydro dams with all the land use questions.
  • It could be supplied by fossil fuel power plants with all the associated extraction, processing, & emissions.
  • It could be generated by nuclear power plants, with all the dangerous minerals, waste, meltdowns, and political issues.

How can making an important efficiency decision be so difficult?
Fortunately, there is a simple, elegant, low-impact solution.

The Solar EV Charging Solution

Solar charging an electric vehicle is easier than you might think.
Consider that 4,000 KWh/year could be generated by as few as 10 standard solar modules in most Canadian lower latitude locations. Thanks to Net Metering programs, you don’t need batteries in your home, or a giant roof rack on your new EV!

Energy Offset
The energy you generate from a solar array on your roof gets used in your home, with any excess going out onto the utility grid. In summer you generate more than you consume and earn credits on your utility account. During winter months, you use-up those credits.

Design Your Array Your Way
Put the solar array on the roof of your home or garage. Choose aesthetic options that further increase the value of your project. Or perhaps build a custom carport or shade structure.
Here’s an example : MyGrid Peak
Garages on the premium side : Lumos Solar Scapes

Solar Industry Impact
Solar modules recover the energy used in their production within 2-3 years, and have expected lifespans of 40+ years, making them one of the most efficient forms of renewable energy. Plus, you will be generating your own energy right where you need it. Clean, quiet, reliable, responsible.

Electricity rates increase by 3-5% annually. With solar, they won’t at your house!

By The Numbers…

EV Energy Analysis: 2019 Nissan Leaf
Base Model : 40KWh battery, 250KM range (est)
Estimated Performance : 6KM per KWh
Typical Annual Driving Pattern : 20,000KM (approx 55KM/Day)
Typical Daily Energy : 10KWh (incl losses)
Typical Annual Energy : 3,700 KWh

EV Energy Analysis: 2023 Tesla Model 3
Base Model : 57.5KWh battery, 350KM range (middle of the road est)
Estimated Performance : 6KM per KWh
Typical Annual Driving Pattern : 20,000KM (approx 55KM/Day)
Typical Daily Energy : 10KWh (incl losses)
Typical Annual Energy : 3,700 KWh

Cost Of Energy (equivalent sized car to a Leaf or Tesla Model 3)
Gasoline…20,000KM / 10KM/L Gas = 2,000L@ 1.79/L = $3,580 /Yr
Electrons…3700KWh @ $0.15/KWh = $555 /Yr

  • Typical Canadian Home Annual Consumption : 12,000 KWh/yr
Solar car park canopy by Lumos Solar

Closing remark…
Some readers will surely note that we are talking about ‘Driving Energy Offset’ here. This is the energy required to move the vehicle down the street. This is not anything to do with the embodied energy in the vehicle itself – what it took to build it. Nor the difference in embodied energy between EVs & conventional ICE vehicles. I will address this interesting topic in a future article. Especially after recently seeing one of the behemoth Hummer EVs. While ‘fuel’ costs would be far lower on this beast, the embodied energy is much higher. Jevons is laughing at us with a big ‘I told you so’!

10 thoughts on “Solar Charging An Electric Vehicle

  1. Brian

    What electrical generating system is your estimate of $0.12/KWh based on? Does it take all costs into account?
    No good Canadian solar power systems manufacturers?

    1. admin Post author

      The $0.12 is an approximation of BC electricity rates (mix of tier 1 & tier 2). Many jurisdictions are higher which makes solar an even better investment. In terms of the solar on your roof, you are offsetting utility power in a grid-tied situation. Unless you install enough solar to reach net-zero status for your home, it’s not possible to say that all your solar went into your EV. Just that you offset a portion of your home’s overall consumption. When amortizing the cost of your solar installation over a 20-year time span, the cost of the energy is on par with current utility rates (ie $0.12-$0.15/KWh). Of course, utility rates rise – in BC they have risen an average of 3.5% per year over the past decade or more. This makes the investment in solar very competitive with other secure investments. Canadian Solar, and a few other companies, have some small module manufacturing capability in Canada. But for the most part, Canada is a technology importer in this sector.

        1. admin Post author

          Exactly. While electric cars are vastly more efficient than internal combustion vehicles, it still matters how you source the electrons to put into the electric car’s battery & motor. Electric motors are over 90% efficient (internal combustions are only about 40%), and modern lithium batteries have a round-trip efficiency of over 90% (almost impossible to determine how much energy it takes to put a litre of gas in a car vs the approx 6KWh you get from it).

  2. Thomas Brown

    I have a plug in hybrid vehicle c/w a 66.9 kw electric motor plus a 13.8 kWh lithium ion battery. Can you tell me what I need as far as a solar system I would need and if possible price for me. I live in southern Ontario

    1. admin Post author

      It all depends on your driving patterns. On average, how much of the battery capacity do you use in a typical day of driving?

        1. admin Post author

          To offset that energy completely, on an annual basis (ie via grid-tied Net Metering credits), would require a system in the 14kW range. Of course, this is all scalable, so a 7kW system could offset 50% of your driving, etc. Costs can vary due to several factors including type of inverter platform, whether you’d like back-up energy storage, etc. But prices can range between $1.75-$2.25/Watt for the equipment.
          Place your order for an assessment of your roof’s generating potential, and equipment estimate here:

    1. admin Post author

      Hi Keith, thanks for your note. Nothing available from Enphase yet, but will surely be popular once officially released. We will be keeping an eye out for CSA/ULc certification for use in Canada.

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