Car owners could save £1,200 a year on bills with a solar carport

Oct 20, 2024

Millions of UK households could save more than £1,000 a year on their energy bills by installing carports made from solar panels in their driveways, experts estimate.

They say that under the right conditions “several million” UK homes could benefit from solar carports, making considerable savings in the process.

The right conditions include having a driveway or parking space that faces south or west and isn’t too shaded.

For those people, a standard 4 kilowatt single-car solar port would give an annual energy bill saving of around £1,100 to £1,200 (including the money made from feeding any excess energy generated into the electricity grid).

And for owners of electric vehicles, concerned that their electricity is still being generated from climate-warming gas power plants, the carports are an opportunity to ensure their car runs entirely on clean energy – and they can also place their chargepoint into them.

Generally, planning permission isn’t required for solar carports or roof panels.

Overall, there are 13 million properties in the UK with a driveway – of which several million might potentially benefit from a solar carport, according to a very rough estimate by Professor Alastair Buckley of Sheffield University, after analysing his data on UK building stock.

For many of them, the longer term savings could prove tempting with energy bills expected to remain high for some time.

But, at £10,000 or more, the upfront installation cost means this isn’t affordable for many people and it is likely to take around 8 to 10 years to pay off the cost through energy savings.

The carport installation costs compares to around £4,000 to £6,000 for roof panels of the same generating capacity, according to data from Cambridge-based Polysolar, which designs and installs solar panels.

A double solar carport, meanwhile, at a cost of around £20,000 or more, could generate 8kW of energy and save around £2,100.

Given the high installation costs, many people would still be better off putting solar panels on their roof, which is typically cheaper (although not always).

But for many households that often isn’t an option, for example because the house is very tall, requiring expensive scaffolding for the installation. It may also be that there are obstacles on the roof, such as chimneys or vent pipes, or the roof is in poor condition.

So for those who have suitable driveways and can’t put solar panels on the roof – and those who already have them on the roof and want to generate even more solar energy – carports could be a good bet.

On 1 October, the energy price cap for a typical household that uses gas and electricity and pays by Direct Debit went up from £1,568 to £1,717 per year – an increase of around 10 per cent which adds around £12 a month to an average bill.

From January 2025, the price cap is expected to increase to £1,762 before falling to £1,722 – although predictions for 1 April 2025 remains uncertain.

The energy consultancy Cornwall Insight predicts that prices will stay flat for three years and, even though they are then expected to dip, will remain 10 per cent higher, after inflation, than they were in the late 2010s until at least the end of the decade.

Professor Buckley believes solar carports are a good option for many households that are being largely overlooked at the moment, although he cautions that “there is a lack of products and they are still relatively expensive”.

“I think it would be fair to say that there is opportunity to innovate in the solar carport space with a potential market being several million homes,” he said.

“In some situations – maybe where the house is tall or the roof is not in a great state – a solar carport would make much more sense than solar panels on the roof. A tall house is more likely to need scaffolding for a safe install and this could be a significant part of the install cost. Even if it’s just a tower it could be many hundred pounds for that alone.”

“And for electric vehicle owners, it would also keep the car cool while charging and this could be a benefit to the battery.”

At the moment, solar carports are rare, both in the UK and overseas, with most installations relating to company and public car parks.

However, interest in residential solar carports in the UK is starting to grow, from households and for apartment block car parks, experts say.

“We get about two enquiries each week for residential solar car ports so there is definitely interest growing,” Jim Williams, of Polysolar told i.

Source: National Grid

“They are particularly popular with people who have already had solar on their house and want more, customers with electric vehicles and customers who don’t want to put solar panels on their roof.

“People have got quite used to solar panels being cheap when installed on a roof, so balk about the cost of a solar car port, but the car port is providing a waterproof structure as well as the solar panels,” Mr Williams said.

“Car owners who want a car port to keep bird droppings, sticky honeydew, tree sap and leaves off their car might find that a solar car port isn’t best suited to them as the tree would likely be shading the solar panels.

“But if they’ve got an open driveway and an electric vehicle then a car port is the perfect place to position an electric vehicle charge point,” he said.

Joshua Holland, of Nottingham-based EvoEnergy, which designs and constructs renewable energy systems, said “the potential for residential solar carports in the UK is promising”.

“While the market remains relatively niche, interest is growing as energy costs rise and homeowners look for sustainable alternatives.

“The most suitable houses for solar carports are those with south-facing or west-facing driveways that receive maximum sunlight exposure, have unshaded spaces to optimise energy generation, and possess sufficient driveway size and structural integrity to support a solar carport.

“While a south-facing roof often offers more consistent energy generation, some homeowners may prefer carports for aesthetic or practical reasons, such as utilising roof space for other purposes or when the roof structure is unsuitable for panels,” he said.

Gareth Simkins, of the Solar Energy UK trade association, said that, in the right location, solar carports “could be a great option for installing solar panels for home energy, and without the need for scaffolding, too”

“Whether they would be a better option than a rooftop installation depends on a variety of factors, such as degree of overshading, the angle of the panels to the ground and what direction the carport or roof faces.

“Rooftop installations would be preferable in most situations, as they would presumably be able to take more panels and thus generate more power. But not every roof is suitable, so that’s where solar carports can definitely shine.”

Separately, research by Solspan, the UK solar carports and carport solar canopy company, estimates that 500 of the largest businesses in the UK could collectively save more than £1.4 billion on their energy bills in the next decade by putting solar panels above their car parks.

Meanwhile, the biggest 8,000 UK companies could save £2.2bn a year if they did this, the research found.

However, Mr Simkins says that if company solar carports are to be used on a large scale, the government needs to significantly increase ‘grid capacity’ – the amount of the excess energy generated that can be fed into the local electricity grid for other consumers to use, which generators are paid for.

“This is very rarely a problem at the residential scale, of a few kilowatts’ capacity,” he added.

A spokesperson for the Department for Energy and Net Zero, said there was a place for solar carports in the UK’s drive to ramp up renewable energy production: “Solar is at the heart of our mission to make Britain a clean energy superpower.

“It is now easier to install solar canopies in car parks and we are powering a solar rooftop revolution on new homes to ensure they are fit for a net zero future.

“This will encourage builders and homeowners to deliver this technology to millions of addresses in the UK so people can provide their own electricity, cut their bills and at the same time help fight climate change.”