electric vehicle and solar panels on a home

How many panels do you need for your EV?

One of the primary benefits of purchasing an electric vehicle is that it allows you to transition from paying for gasoline to lower-cost electricity. But why not take that one step further and power your car with clean, solar power you produce on your own property? Here’s a  quick breakdown to help determine how many solar panels you need to power your electric vehicle (EV) with solar. 

How much electricity do leading EVs require per charge? 

There are a couple of different ways to think about the electricity that an EV requires. The first is to consider the charge required per miles driven, typically expressed in kilowatt-hours per 100 miles driven (kWh/100 mi). The other way to think about the electricity required to run an EV is to consider the electricity required to fully charge the car. This metric is closer to how we currently think about how much it costs to fill up a tank of gas on internal combustion engine cars. 

CompanyModelBattery size (kWh)Range (miles)
TeslaModel S100370
KiaSoul EV64243
ChevyBolt EV60238

The electricity required to “fill the tank” for an EV is equivalent to the size of the battery. Generally speaking, electric vehicle batteries can store between 25 and 100 kWh, with that variation mainly driven by the range that a certain car can cover on a single charge. For a sense of scale, home energy storage systems, such as the LG Chem RESU 10H and the Tesla Powerwall 2, often store around 10 to 15 kWh of electricity. 

How much electricity will an EV use per year? 

How much electricity an EV consumes per day, month or year depends primarily upon how far you drive. If you live in an urban area and own a car but drive it infrequently, the electricity required to power your EV will be relatively small over the course of the year. On the other hand, if you live in a suburban or rural area and commute in your car every day, then the electricity required to power your car could represent a sizeable portion of your annual electricity usage. 

According to the Federal Highway Administration, the average American travels nearly 13,500 vehicle miles per year. At that level of driving, most EVs will require around 4,000 kWh of electricity per year to operate.

CompanyModelkWh/100 miAnnual electricity usage (kWh)
TeslaModel S273,600
KiaSoul EV263,600
ChevyBolt EV253,400

How many solar panels do you need for your EV?

To calculate the number of solar panels required to power your EV, you’ll need to know three key data points: 1) how much electricity your car will use annually, 2) the wattage of the solar panels you are planning to install, and 3) how well solar panels produce electricity where you live. 

As outlined above, for an average American driver, a typical EV will require about 4,000 kWh of electricity per year. According to the most recent EnergySage Solar Marketplace Intel report, the most frequently offered solar panels on EnergySage are in the 320 to 330 Watt range. Finally, the production from your solar panels will vary from region to region, with each panel producing more electricity in sunnier climates–such as the Southwest–than they will in the Northeast. 

Pulling all of these data points together creates a range of solar panels required to power different types of EVs each year in different regions. Depending upon where you live, charging an electric vehicle typically requires 7 or 9 solar panels.  

CompanyModelNo. of panels required: NortheastNo. of panels required: Southwest
TeslaModel S86
KiaSoul EV86
ChevyBolt EV86

Again, it’s worth noting that these calculations are based heavily upon the assumption that you drive the same amount per year as the average American driver. If, however, you drive less than 1,000 miles per month, then you would need fewer panels to power your EV. 

Want to power your EV with solar? 

If you are purchasing an electric vehicle, why not power it with the sun? When you register for a free account on the EnergySage Marketplace, you can indicate that you would like to power an EV with solar panels, and our network of local, pre-screened solar companies will help design a custom system for you that meets your specific needs.

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Categories: Electric Vehicles
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About Spencer Fields

Spencer is the Manager of Market Strategy & Intelligence at EnergySage, where he's able to showcase his expertise around all things energy. Prior to joining EnergySage, he spent five years at Synapse Energy Economics, providing environmental, economic and policy analysis for public interest groups. Spencer has degrees in Environmental Studies and Hispanic Studies from Brown University, meaning when he's not in the office you can find him outside or traveling somewhere to work on his Spanish.

13 thoughts on “How many panels do you need for your EV?

  1. Michael White

    I’m not buying an EV until I find out they can be charged completely free with solar energy and last for many many years to come.


    You explained everything in a very lucid manner.
    It got my concept clear.
    One thing that I would like to add is that in addition to the variation in the sunlight, there are losses in the system such as:
    Temperature losses
    Shading losses
    Dirt loss
    Transfer and conversion losses etc.
    When we consider these losses in addition to the variation in the sunlight,
    the average panels’ size will increase say by 10% to 20%.
    For example,
    Charging a Tesla electric car battery 100 kWh and 370 miles range when Peak Sun Hours are 5 and the system losses are 20% would require:
    = {100/(370 x 5 x 0.8)} x daily average travel time
    = 2.5 kW
    or around 8 solar panels of 310 watts.

    You made the right approximations.

    Thank you for sharing such an insightful post.


  3. Mark Drnek

    Will spent car batteries become a waste disposal issue when they need replacement?

    Thanks in advance for your response.

    1. Robert m

      The best thing for you to do is compare the damage caused by gasoline and refined crude oil.
      Do you know the smell you smell when you leave the gas station it’s on your hands it’s on your feet it’s on the side of your car it runs into the rivers etc. etc.?
      Do you know the production of batteries is less caustic than all the work that goes into making the main ingredients to power a car or truck a boat a plane? And all the Materials needed for a battery can be easily recycled today up to 90%.
      Simple research can give you the answers you’re looking for and when looking into future transportation models EV‘s can be and probably will be the best choice for long term improvements that can last centuries

  4. Paul D Hardin

    I have ordered an EV and I’m considering solar as a power source. I live in Central Florida and have plenty of sunshine. If I go this route I would like a system that can be added on to for future solar.

  5. Ralph Lin

    Hi Forrest, I don’t know whether Tennessee charges based on Time of Use (TOU as it is called), but you can either program your EV or your home charger to re-charge your EV during cheapest times of the day (typically middle of the night). If you want to get fancier, you can also buy a home battery (like a Tesla Powerwall or equivalent) and charge the battery from your panels during your excess generation (say midday) and use the battery to re-charge your EV from your battery. Just note that these home batteries have limited capacity (For one Tesla Powerwall, it is roughly 13kWh). Your EV may need more than that depending on how much you drive. Furthermore, the the Powerwall can only output 3.3 kW. So it will likely charge more slowly than if you were to rely on the grid. Hope this helps.

  6. Bob artin

    It depends on how fast and how many miles you drive each day. The model 3 I think uses about 250 watt hours per mile. .that means 1 kWh will take you 4 miles if you drive 100 miles a day you will use 25 kilowatt hours per day every day you commute. if you buy the most efficient 22 1/2 % panels at about 3(0 watts output full sun, with an output figured at about 5 hours average full output, , then 360 x 5 = 1,800 watt hours per day per panel or 1.8 kWh. . I would guess a 100 mile per day commuter would average about 20kwh per day (maybe much less on the weekends. , so 20 kWh per day divided by 1.8 kWh pet panel per day = 11 panels for a heavy commuter. my son commutes 122 miles per day in his
    I pickup at 15 mpg costs about $500 per month. , so each panel will be saving him about $45 per month in gas. It’s not a crazy way to figure it because it took a new long commute to get him to buy an electric car, and now solar panels.

  7. Ajay Goyal

    Great way to go….. a 5-15KW System for your EV…. not a bad way to go….. 100% Green…. AND WITHOUT ANY “Connection Charges” etc… by Utilities…
    Also shows how much energy our vehicles use… unfortunately…. but better to “use thd sun” rather than pollute “somewhere else” with dirty Fossil & Nuclear Plants….
    Should Qualify for Federal Tax Credits/Grants….. not sure about States though…. as many need you connect to the grid if you want State Ctedits (quite stupid way to go/legislate)…

  8. Forrest Lowell

    I do t get paid for my excess solar production in Tennessee. Is there an EV charger that will adjust its charge rate to match my excess solar production at any given time? That way I maximize self consumption.

    1. Joe Horton

      Did you figure out how to do this? Is it the inverter or the level 2 charger that has to deal with limiting current? Are the needed components a MPPT solar panel controller then a 240 split phase inverter, then a transfer switch so you could choose to use grid power, and finally a standard level 2 charger. Or micro inverters on each panel? Then only a transfer switch. I am in TN also- one way metering which is fairer to folks that can’t have roof panels.

  9. Steve Wehr

    Hi Spencer, I believe you have calculated the KWh/100 miles incorrectly. I did the calculations for the first three cars on the list: I get 27 for the Tesla, 46 for the Audi, and 25 for the Kona. Can you check this please?


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