James Rowe: Solar power is back in the headlines with a recent flurry of interest sparked by a spike in global energy prices. But is it worth it for your home?
Hello and welcome to Which? Shorts, your free weekly insight into Which? magazine, as well as our money, tech, travel and gardening titles too. Today, I'm bringing you a piece that our sustainability expert Karen Lawrence wrote for the June issue of Which? magazine, all about solar panels. With energy prices due to spike in July with a rise in the energy price cap, more people are considering installing solar panels. But there's a lot to consider before you decide to add them to your roof. Here's Karen's piece, adapted for the podcast, this week read by me, James Rowe.
James Rowe: Solar panels are already popular with UK households with around 1.65 million homes now generating their own solar energy. And the market is growing. The latest data shows that 27,000 solar installations were completed in March this year – the highest total since 2012. A 2025 report from the Department for Energy Security and Net Zero found that an average homeowner could save around £500 a year by installing rooftop solar panels. That means the payback time can be relatively short compared to other energy-saving home improvements, and installation is often more straightforward too.
But is your home suitable? Here's how to decide whether solar is right for you, how to find the best solar panels and installers, and how to make the most of your system once installed.
Start by assessing your home. To generate maximum power output in the UK, a large, south-facing, 30 to 40 degree pitched roof in the south of England, free from shading, would be ideal. If your home doesn't quite match this, solar panels can still work well, but some factors affect output more than others. Southern areas of the UK get around 20% more solar energy than those furthest north. But if other conditions are favourable, panels can still be worthwhile if you're up north.
No matter where you are in the country, if you have a north-facing roof or one heavily shaded by buildings, trees or other objects that can't be removed easily, solar panels may not generate enough energy to repay the installation cost. You can use an online calculator to help you start working out your home's specific potential. Most installers will offer a free quote, but we'd recommend an independent solar feasibility report, which will cost you around 150 quid. This is an unbiased assessment from a third party to determine if solar panels are a viable choice for your home. This will give you impartial advice on technical suitability, system design, and estimated costs and savings.
Next, get to know your panels. As a domestic customer, you normally buy solar panels through an installation company. Most installers only work with one or two panel brands, so it's worth getting a few quotes to compare what's offered. Key things to look for are the efficiency and power rating, length of warranty, and value for money. If the panels will be visible, you might also consider how they look.
Solar panel efficiency, by the way, refers to the percentage of daylight a panel can convert to electricity. Most panels installed in the UK are now all-black monocrystalline. The best of these are rated at around 25% efficiency, but others are not far behind. A solar panel's life can be 30 to 40 years and most come with a product warranty ranging from around 12 to 25 years. They also include performance guarantees, which offer a minimum performance level such as 88% of initial capacity after 30 years.
If you decide to get solar panels, consider a storage battery too. You see, the downside of using solar panels as a primary source of household electricity is that most of us use a lot of power in the evenings when it's dark outside. In daylight hours, your panels may generate more than you use, especially if you're not home. A battery enables you to store the excess electricity to use when you need it. You can also charge the battery using your mains electricity supply. This can be cost-effective if you sign up to one of the time-of-use tariffs that are becoming increasingly available. You can store cheap electricity during off-peak hours, often early hours of the morning, to use at peak times.
But adding a battery to your solar PV system considerably increases the upfront cost by around £2,000 to £6,000 for sufficient capacity for typical UK rooftop systems. So be sure to ask your installer or an independent solar expert to calculate your potential savings both with and without a battery so you can weigh up your options.
Speaking of an installer, who should you go for? Well, just under half of Which? members who have solar panels that we surveyed used a local independent trader, while a quarter used a nationwide firm. There could be pros and cons to both. When you're ready to seek quotes, look for installers certified by the MCS or Flexi-Orb, as you'll need an MCS or Flexi-Orb certificate to qualify for export payments – more on this in a moment.
Make sure they offer an insurance-backed guarantee, which means you'll be covered even if they go out of business and can't fulfil their warranty, as warranties can be as long as 25 years. As with any large home improvement project, get at least three quotes and make sure it's clear what is included. To compare quotes, divide the total cost of the system by the total power output to find the price per watt of power output. According to MCS, in 2025, the average installation cost per kilowatt hour was around £1,650.
When you get your quote, make sure it covers things like scaffolding, labour and extra costs such as bird or squirrel protection. It's also worth asking what support is available after the installation. Certified installers must provide at least a two-year workmanship warranty, although some also offer ongoing monitoring and maintenance. This may come at an extra cost. The Which? Home Energy Planning Service on our website can help you decide whether solar panels are right for you, highlight available grants or support, and help you find trusted local installers.
Finally, if you take the leap, make sure you make the most of it. How you use your solar panel system makes a big difference to your energy savings. It's usually better to use as much of your own solar power as possible to replace expensive grid energy. If no one is home during daylight hours, you may not save as much on your bills. Battery storage, time-of-use tariffs, and your ability to schedule or automate appliances that use a lot of energy will all also affect your savings.
You can sell surplus power back to an energy company under the Smart Export Guarantee scheme. But even with a competitive tariff, the rate you'll get is lower than the average retail price. According to Ofgem, households on an export tariff in 2024–25 earned 13p per kilowatt hour on average – less than half the typical price-capped cost of electricity.
We've got loads more advice on solar panels on our website to help you weigh up whether they're right for you, including what you need to know about plug-in solar panels that you could start to pick up when you do your supermarket shop. Check the show notes for loads of useful links.
Thanks for listening to this podcast from Which?, the UK's consumer champion. You can find plenty more advice about what we discussed today in the show notes. There you'll also find a link to become a Which? member for 50% off the usual price – an offer exclusively available to you, our podcast listeners.
Joining Which? will not only give you access to all of our product reviews, our app, one-to-one personalised buying advice and every issue of Which? magazine across the year, but you'll also be helping us to make life simpler, fairer and safer for everyone. Don't forget to hit subscribe wherever you're listening, that way you'll be notified whenever we release a new episode of Which? Money, Which? Shorts or another podcast that we make for you. And if you want to get in touch with us, then follow us on social media where we're @WhichUK, or you can drop us an email to podcasts@which.co.uk. See you then!
