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  • Sep 29, 2022

  • 8 min read


A guide to solar panel EV charging

Are you one of the growing number of people looking for nifty ways to reduce your reliance on fossil fuels? You’re in the right place my friend.

Have you considered using solar energy to charge your electric vehicle? Not only is this a more sustainable option, but it can also save you money in the long run. Green and cheap, just the way we like it.

In this article, we’ll go through the benefits of using solar power to charge your EV and how to get started.

How does solar panel charging work?

Battery charging from solar panels is a renewable and sustainable way to power your electric vehicle. Simply put, solar panels work by converting sunlight into electricity, which can then be used to charge your EV battery. Solar panels are typically installed on the roof of a home or business, and can be connected to support all your electrical devices and to the electrical grid, so that excess electricity can be sold back to the utility company - this is done through Smart Export Guarantee Tariffs. Yep, you can get paid for producing your own electricity at home. Ka-ching.

Even better, your solar panels can be directly connected to your EV charger, meaning those electrons produced on your roof can directly feed your car. This means solar panels are a great option to reduce your carbon footprint and make long-term cost savings, as you use the power you've generated.

Can you really charge an electric car with solar energy?

Yes, you can fully charge an electric car with solar energy. You’ll need to put up a domestic Solar Photovoltaic System (Solar PV), along with the solar charger for the car battery. Solar panels and electric vehicles are a match made in heaven, on your roof.

Solar PV systems generate electricity from the sun, which can then be used to charge an electric car or anything else in your household. The average domestic solar PV system can generate one to four kilowatts of power (kWp). This is enough to fully charge an electric car with a battery capacity of 40 kWh in just over eight hours.

Of course, the amount of solar energy available to charge an electric car will vary depending on the time of year and the weather conditions. In winter, when there is less daylight and more cloud cover, you may need to supplement your solar PV system with power from the grid. But solar energy is a great way to charge an electric car in a really sustainable way, even if you only partly charge the car.

How many solar panels do you need to charge a car?

Generally, larger batteries need more panels. So if you're looking to install a solar PV system specifically for charging your car, it's best to speak to a professional about the right size and type of system for your needs. On average, a solar panel system with around 8-12 panels can power an electric vehicle - but please check this with whoever is installing your solar panels.

Don’t have room for solar panels but still want to charge your EV with sustainable and green energy? No problem! With a green EV tariff like the ones from Octopus Energy, all the electricity you use is sourced from renewable energy generators, like solar and wind farms. So not only are you doing your bit for the environment by driving an electric car - you're also charging it in one of the most sustainable ways possible. To find out more about EV charging with solar energy, contact us today.

Can you use a regular EV charger with solar panel charging?

Yes, you can use a regular EV charger with solar panel charging but you'll need a PV inverter unit that converts solar energy into electricity in order to start charging your EV with solar panels. Most installations will have an inverter as standard but it’s important to check. The inverter is what changes the current from DC to AC so you can use electricity from the panels to power your home and devices. EV home chargers use AC.

Some EV chargers already have this technology in the box (like the My Energi Zappi charger) so you can start charging straight away, but again, it's important to check.

Secondly, solar panels generate power during daylight hours (when we get more sun), but most people charge their electric car overnight while they’re sleeping. So, if you want to charge your EV using that solar power at night, you’ll need a battery storage system that stores the energy generated throughout the day and then releases it when you need it - such as at night when charging your EV.

The pros and cons of using solar panels to charge your EV

There are a few things to consider before you switch to solar panel charging for your EV. Here are some of the pros and cons:

Pros of installing solar panels to charge your EV:

  • Solar panel charging is good for the environment. Electric cars are much cleaner than petrol or diesel cars, but if they're charged using electricity from coal-fired power stations, their environmental benefits are reduced. Solar panel charging helps to maximise the environmental benefits of driving an electric car.
  • Once you've installed your solar PV system, it will continue to generate electricity for years to come with very little maintenance required. Energy Saving Trust estimates that a typical home solar PV system could save around one tonne of carbon per year.
  • Solar panel charging is cheaper than grid electricity. In most cases, the cost of generating your own solar power is lower than buying power from the grid. This means that you could save money on your EV charging costs in the long run. The Energy Saving Trust estimates that an average 4kW solar array in the UK will save you over £400 a year.
  • Solar PV systems can generate enough electricity to fully charge an electric car. A typical domestic solar PV system can generate around four kilowatts of power, which is enough to charge an electric car.
  • Domestic solar PV systems can bring you savings on your energy bills. Not only can you save money on your EV charging costs, but if you generate more electricity than you use, you can sell it back to the grid and reduce your overall energy costs.

Things to consider before installing solar panels:

  • Solar PV systems can be expensive to install. The initial cost of buying and installing a solar PV system can be substantial. The government offers generous financial incentives for domestic solar PV installations in many countries, so it's worth checking whether you could get a grant or subsidy to help with the cost.
  • Solar panel charging requires sunny weather. Solar PV systems only generate electricity when the sun is shining, so if you live in a cloudy climate, solar power may not be the best option for charging your EV. But it's worth noting that solar PV systems can still generate some electricity on cloudy days, but you may need to supplement your solar PV system with power from the grid in wintertime.
  • Solar panel charging can take longer than grid charging. Yes, it takes longer to charge an electric car using solar power than it does to charge from the grid. But, if you have a solar PV system installed, you can charge your EV overnight while you're sleeping, so it will be ready to go in the morning.

Overall, there are loads of advantages to using solar panels to charge your EV. Solar energy is renewable and sustainable, it's usually cheaper than grid electricity, and it doesn't produce any emissions. So, if you're considering making the switch to solar panel charging for your EV, it's definitely worth exploring further.

Learn more about our EV charging and green EV tariffs from Octopus Electric Vehicles today.