Can you use solar panels to charge electric cars?
A guide to integrating solar panels with a home chargepoint to charge your electric vehicle.
Last updated: Apr 03, 2024 • 7 min read
Summary
Using a solar array system with a compatible electric vehicle (EV) charger can be a great way to keep your car charged on renewable energy.
When combined with battery storage, solar panel charging can be:
Greener
Cheaper
More convenient
How does solar panel charging work?
Installing solar panels can allow you to generate renewable energy during the day, which you can then use to charge your EV:
The photovoltaic cells of the solar panels absorb sunlight as DC energy
A solar inverter converts this energy from DC to AC, which can be safely used by home appliances
This energy powers your home and appliances via the consumer unit
If you have battery storage, any excess energy that isn’t in demand gets stored for later use. This can then be used by the grid to distribute your surplus energy.
Tip: Pod Point’s home chargers can integrate with most domestic solar systems.
What are the benefits of using solar panels to charge your EV?
1. Clean energy
Electric cars are already inherently more eco-friendly than driving petrol or diesel equivalents. By powering your EV with solar energy, you can further minimise your carbon footprint to make going electric even greener.
2. Savings
Excluding the costs of purchasing and installing solar panels, energy generated by solar power is effectively free. After all, you don’t have to pay the sun to use its sunlight!
This can be especially beneficial when combined with electric cars as the costs of charging are often much lower versus traditional fuels used to power cars with internal combustion engines (ICE).
Better still, some tariffs allow homeowners to sell back their surplus energy to the National Grid.
Tip: electric cars have many other benefits over petrol/diesel vehicles. For example, maintenance costs are typically lower for EVs as their drivetrains are simpler, and new technologies make batteries last even longer.
3. Convenience and flexibility
The majority of EV charging at home takes place overnight when demand is lowest and cheapest. By doing this, drivers ensure they wake up to a full battery every morning, with the charging stopping automatically once the battery reaches its maximum capacity.
Using solar panels to charge your EV during the day adds an extra layer of convenience. This lets drivers choose to charge either overnight and take advantage of cheaper electricity, or during the day time with clean and renewable energy.
Tip: With Charge Scheduling, you can benefit from dual-rate electricity tariffs and schedule your EV to charge during off-peak hours.
4. Grants and schemes
The UK Government has promoted renewable energy sources for many years. Although some of the solar grants have now expired, there are still some EV drivers can take advantage of:
Energy Company Obligation (ECO4)
The latest iteration runs from the 1st April 2022 to March 2026, with the government allocating £4bn to improve the energy ratings of UK homes.
It’s open to any low-income, fuel-poor or vulnerable household receiving benefits, which covers around 450,000 homes. Using the scheme, households can replace older heating systems with more efficient and eco-friendly versions, including solar panels.
Those that qualify could reduce their average household energy bills by as much as £1,600 per year.
Smart Export Guarantee (SEG)
This scheme is focused on allowing smaller-scale and low-carbon electricity generators to offer an export tariff to their customers. Using this, they can get paid for any energy they send back to the grid.
It came into effect on the 1st January 2020, and currently has no end date. Suppliers with more than 150,000 customers must offer the tariff, whilst smaller providers have the option.
Any householder with solar panel systems are eligible, although they must have a smart metre to measure the exports.
0% VAT
From April 2022, the government introduced zero VAT on the materials and installation of any measures to improve the energy efficiency of a home.
This applies not just to solar panels, but also heat pumps, insulation, and other energy-saving systems, with only one or two specific requirements for households to be eligible.
The reduction only runs for five years, after which the VAT rate will return to its standard 5% rate.
Things to consider with solar panels
Although there are many upsides to owning solar panels, there are some things EV drivers should take into consideration.
1. Initial costs
Installing both an EV chargepoint and solar panels can be expensive, although there are grants available to recoup some of the installation costs for both.
Whilst solar panels can reduce energy bills, it can take a number of years to break even on the investment, even after accounting for any reductions in costs.
2. Practicality
Solar panels have certainly become more efficient, with new technologies enabling better energy collection and more efficient storage solutions.
However, there’s a significant limiting factor to how efficient and practical they are: sunlight. Simply put, the less sunlight there is, the less energy gets generated from solar panels. This naturally has a knock-on effect on the savings they produce, and their ability (or lack of) to charge an EV.
Governments and businesses across the globe recognise this as an obstacle, with some developing innovative solutions to tackle the problem. One such solution is being developed by scientists in China, who aim to use the motion of raindrops to produce energy instead.
Can Pod Point chargers integrate with solar panels?
Yes, Pod Point chargers can integrate with solar panels. When energy is generated by them it feeds into the mains supply, which can then be used to supplement the energy used to charge your EV.
However, they can’t be used to exclusively charge your EV as Pod Point chargers can’t automatically reduce their in-built charging rates to match the energy generated by the solar panels.
Even if they could, you would likely end up with a much slower charging rate than what the charger provides. To start with, solar arrays generate ~4kW in perfect conditions, which in the UK isn’t very often. So if you have a 7kW or faster charge, you would be limited to the rate the array generates energy.
Conversely, if the array generates more than your charger’s maximum rate, you wouldn’t be able to utilise all of it. For example, if you have a 3.6kW charger and your solar panels are generating 4kW, your EV would still only charge at a maximum of 3.6kW.
Tip: it’s also worth remembering that solar panels only generate energy when there’s daylight. So if you charge your EV after sunset (which is very common, especially in the UK in the darker months), you’ll need your mains supply to charge it, which is counterproductive.
How many solar panels does it take to charge a car battery?
You could charge a car battery with just one average 350W solar panel, but it would take longer than using a solar array consisting of multiple panels.
A typical 4kW solar panel system is made up of around 14 to 16 panels. This would be enough to power a 3.6kW home charger in perfect weather conditions - in theory. In practice, conditions are rarely perfect in the UK. You’ll likely have to supplement your power with energy from the grid to charge your battery.
How long would it take a 100W solar panel to charge a car battery?
It takes a typical car battery (60kW) around 60 hours to charge from empty-to-full if a solar panel was consistently supplying 100W. However, the power supplied can rise and fall as weather conditions change, making it more likely to take longer.
So, it’s possible to charge an electric car battery using a 100W solar panel, but it’s not very practical. In comparison, using a standard 3-pin plug would take less time, around 26 hours, to fully charge an EV battery.