Charging an Electric Car with Solar Panels
Combining electric driving with solar power introduces an efficient way to lower your carbon footprint and energy costs.
In this guide, we’ll outline how to charge an electric car with solar panels, as well as cover all the benefits and key considerations you should take into account, including the costs involved.
Can you charge an EV with solar panels?
Yes, if you have a standard home EV charger installed at home, it will work with solar panels. Your home EV charger can either draw electricity from the grid, straight from your solar panels, or you can switch to the electricity stored in your solar system’s battery.
If you have a smart home EV charger that is solar compatible you can also ensure you take advantage of times when solar energy generation is at its peak or use the stored energy to recharge your EV overnight.
What do you need to charge an EV with solar panels?
To charge an electric car using solar panels, you will need four key elements.
Solar Panels - Starting with the obvious, in order to generate electricity you will need to install solar panels on the roof of your home. These will convert the sunlight into electricity, which can then be used to charge your EV directly.
PV Inverter Unit - To convert the energy from the sun into usable power for your electric car, you’ll need a PV Inverter Unit. These units convert DC electricity generated by the solar panels into AC power. This is required as your home EV charger requires AC power (even though your car battery requires DC charging!).
Home EV Charger - A home EV charger allows you to charge an EV from home by drawing electricity from the grid. However, home EV chargers also allow you to switch your energy supply to the solar panels installed on your roof.
Solar System Battery Storage - Adding battery storage to your solar system allows you to store energy generated through your solar panels to be used at a later time/date. It’s an optional extra for your solar system but is a worthwhile addition if you plan to recharge your EV overnight or when sunlight is at a minimum.
When is the best time to charge an EV with solar panels?
In order to make the most of solar power, charging your electric car with solar panels is usually most beneficial between the hours of 10 am and 4 pm. This is when most sunlight occurs and thus reduces the reliance on pulling electricity from the grid.
How many solar panels do I need to charge an EV at home?
The number of solar panels required to charge an EV will depend on a few factors, such as the size of the electric car’s battery, how often you use the electric car and how much sunlight the solar panels you install will be able to capture on an average day.
On average, a standard solar panel produces between 300-400 watts (0.3-0.4 kW) under optimal sunlight conditions. This output varies depending on factors such as panel efficiency, angle, location, and hours of sunlight received each day. For simplicity, let’s assume each panel provides approximately 1.5-2 kWh of electricity per day in an area with good sunlight exposure.
For a smaller EV (around 40-50 kWh battery) with a 30-mile daily drive, 8-12 solar panels might suffice to cover most charging needs without drawing from the grid, provided sunlight conditions are favourable.
For larger EVs with more substantial battery capacities or for higher daily mileage, you might require 12-20 panels to reliably meet both household and EV charging needs.
To cover household energy needs and consistently charge a mid-range EV, aim for 15-20 solar panels to achieve a balanced setup that minimises grid reliance year-round.
Bear in mind the power output of solar panels on a gloomy day in the winter will be around 20% of the peak output from a sunny day in summer.
How long does it take to charge an EV with solar panels?
On a day when the weather is favourable, the average domestic solar system that produces between 1-4kW of power can fully recharge an EV with a battery capacity of 40kWh in approximately 8 hours.
If you attempt to recharge your EV on an overcast day, the charge time may increase if electricity hasn’t already been stored. This may require supplementation of power from the grid.
What are the benefits of charging an EV with solar panels?
There are three main benefits of charging an EV with solar panels versus other methods;
Reducing energy bills
When you generate your own electricity through your solar panels, your reliance on drawing energy from the grid is reduced, thus helping to reduce your energy bill. By taking full advantage of sunny days to recharge your EV or to fill up your home’s solar battery, storing excess energy for another time, the greater the savings will be.
Lowering your carbon footprint
By using solar panels to charge your EV, you are taking advantage of a renewable and clean power source. This is a much greener option compared to drawing energy from the grid and, of course, refuelling a petrol or diesel vehicle.
Flexible charging
Having the ability to store electricity generated by your solar panels in your solar battery allows you the freedom to recharge your EV at a time that suits you. You don’t need to wait for a sunny day or worry about recharging if there’s a power outage, as it’s all there ready to go whenever you are.
How much money can you save on your bills by charging an EV with solar panels?
Taking advantage of renewable energy from the sun not only provides a constant stream of energy to charge your electric car at home, but it can also help you save on your energy bill.
According to energy provider E.ON, depending on the number of solar panels installed, EV drivers can expect to save between £551 and £1,432 per year for those without a solar battery, or between £589 and £1,501 per year for those with a solar battery.
What to consider if you’re thinking about solar panel charging
If you’re thinking about charging your electric car using solar panels, there are a few important considerations to take into account beforehand.
Solar panel installation costs
You can save a lot of money in the long term by utilising the renewable energy generated by solar panels. However, the initial cost to install a typical 3-4 kWp solar PV system could set you back around £8,000.
Roof space
One factor many people forget is whether or not your roof has the adequate amount of space and sunlight required to cover both your home and EV charging needs.
Storage space
If like many you’d like to recharge your electric car overnight, it would be beneficial to also invest in a solar battery storage system. This will allow you to recharge your EV without the aid of sunlight.
Charging an EV at home with Kerbo Charge
Whether you’re going down the solar panel route, or simply want to charge your electric car at home, the challenges for those with no driveway are becoming a thing of the past thanks to Kerbo Charge.
We organise the professional installation of a charging channel or cable gully outside your home, enabling homeowners with on-street parking to charge their EVs safely and securely. If you’d like to know if Kerbo Charge can help you, simply enter your postcode to see if our services are available in your area.
PLEASE NOTE: This article is not intended as electrical safety advice - you should always seek advice from a qualified electrician.
