To help you get the best from your solar panels, we’ve asked solar experts for their advice, and owners for their top tips.
Cutting your electricity bills and your carbon footprint are two of the biggest reasons people choose to install solar panels. How you use your solar panels is key to doing both. Our tips – gathered from experienced solar panel owners and experts – will save you hours of research and help you maximise the benefits of solar panels. Plus we reveal the answers to common questions about maintaining, cleaning and using your solar panels.
Cutting your electricity bills and your carbon footprint are two of the biggest reasons people choose to install solar panels. How you use your solar panels is key to doing both. Our tips – gathered from experienced solar panel owners and experts – will save you hours of research and help you maximise the benefits of solar panels. Plus we reveal the answers to common questions about maintaining, cleaning and using your solar panels. Live more sustainably: get our free monthly Sustainability newsletter to make eco-friendly changes for you, your home and the planet
How can I maximise profit from my solar panels?
Once you’ve invested in solar panels, make the most of them by using as much of the free renewable electricity they generate as possible. Compare the price you pay for electricity from your energy supplier with the amount you are paid for exporting your excess solar electricity to the grid to find out how much you could save on your bills. To get paid for exporting solar electricity you’ll need to sign up for the Smart Energy Guarantee. If you have had solar panels for a few years, you might receive Feed-in Tariff payments. Solar panels typically produce most electricity during the daytime in summer when it’s sunny. Owners told us how they’ve adapted their routines to use more of their solar electricity: ‘We have moved dishwashing and clothes washing to daytime where possible.’ ‘We have adapted our energy usage to use electricity at peak PV output times by setting timers for appliances.’
‘We try and get maximum use of the electricity generated by only using one appliance at a time when the system is generating.’ ‘Using the delay start functions on the dishwasher and washing machine ensures they run when we are likely to be generating. We’ve shifted ironing from an evening to a daytime job, and avoid running heavy-current items like the kettle and toaster at the same time if we are generating.’ ‘We have an immersion heater control that heats water from excess generation and as a result we switch off our gas boiler in summer.’
‘We try to charge the car on sunny days.’ ‘The panels work best during the morning and early afternoon and as we cook and eat at lunch time this works fairly well.’ If you’re not at home when your panels are producing most of their electricity, you have several options: Use timer switches or delay start functions on your appliances to schedule them while you’re out. Note that you should never leave a tumble drier running unattended.
Divert excess electricity from your solar panels to your immersion heater to heat your water. You’ll need a solar pv immersion heater controller (popular brands include immerSun and Solar iBoost). Store excess electricity in a home battery. These can be a big investment, but they let you use your solar electricity at a time to suit you. Find out more about solar panel battery storage. Owners also recommend that you keep a regular eye on how much electricity your panels generate, so you can spot any irregularities that might indicate a problem with your system.
Do solar panels need cleaning?
Not always. Solar pv panels should be self-cleaning, especially if your roof has the right incline. A heavy rain shower should be enough to clean them. However, if the following are true of your system, then the occasional clean can help keep them working at full capacity: birds regularly roost on your roof and soil your panels trees drop leaves onto them salt builds up on your panels because you live near the sea inner-city traffic pollution creates a film on your panels. Monitor how much your solar system generates. If you see an unusual drop, check with your installer what the reason could be. It might be that your panels need cleaning, but it could be something else. See other solar panel problems and how to solve them.
Can I clean my solar panels myself?
If your panels have built up more dirt than natural rainfall is removing and you think it’s affecting how much electricity they generate, consider your options for cleaning. It’s possible to clean your own panels and solar panel cleaning kits are available online and from some hardware stores, costing £50-£100. We’d recommend you look for one with an extendable pole so you can clean them from the ground. But there are also many companies offering solar panel cleaning services. Speak to a couple of companies and get quotes so you know the going rate in your area before you commit.
Will I need to replace the inverter?
Most string inverters will come with a five to 10-year warranty. Since many solar panels have a 25-year warranty, that means you will probably have to replace your inverter at least once. Take this into account when budgeting. On average, they cost: Between £900 and £1,600 for professional installation Between £500 and £1,000 if you buy one and fit it yourself* More than one in 10 (14%) solar panel owners in our survey told us they’ve had a problem with their inverter since installing their solar PV system. That’s according to our survey of 1,116 solar panel owners in June 2021. When you come to replace the inverter, check the warranty. *Survey of 1,987 solar panel owners in May 2019.
What happens if my solar panels are shaded?
Shade is bad news for solar pv panels, so watch out for chimneys and trees. Remember that over the 25 or more years you will have the panels, young trees may grow to shadow them. Even if just one panel is in the shade, the whole system’s performance will be hampered. This is because solar panels are typically connected together in ‘strings’, which means one panel is linked directly to the next. In small installations, panels are often in a single string so one panel being shaded can affect them all. Check that your installer has thoroughly looked at any risks of shade on your roof, and has used the right ‘shading factor’ when calculating return on investment. Ask to see the calculation. If a shading factor of ‘1’ has been used, that assumes your system will have no shading at all, ever. Modern systems are often fitted with bypass diodes which let electricity move around the affected shaded area, reducing the affects of shading.
What if my neighbour’s tree shades my panels?
If your panels become shaded because of a new development next door, or your neighbour’s tree grows, the law is unclear about your rights – even as to whether a ‘right to light’ applies to solar panels. A Law Commission Consultation Paper in 2020 said that ‘objects that do not have apertures such as solar panels are almost certainly not capable of benefitting from a right to light’. We strongly recommend you get legal advice if you’re in this situation, but a good neighbour relationship from the start can always help.