Solar panel myths, debunked

"They don't work when it's cloudy." "They'll wreck my roof." "You'll never make your money back." Some solar myths are half-true, some are flat wrong, and a few cost people real savings by talking them out of a sound investment. Here's what the evidence actually says, one claim at a time.

"They don't work in the cloudy UK"

Panels run on daylight, not direct sun, so they keep generating under cloud, just at reduced output. The telling comparison is Germany: for years the world's leading country for installed solar per person, on roughly the same sunlight the UK gets. Most of England sees about 850 to 1,000 kWh per kWp a year. It's irradiance that matters, not heat. Panels actually lose a little efficiency when they get very hot, which is why a bright, cool spring day can outperform a sweltering one.

"You'll never make your money back"

Payback for a well-matched system usually lands in the high-single-digit to mid-teens of years, and the panels keep working for 25 to 30 or more. The number that matters is the 25-year net benefit after degradation and rising energy prices, not the sticker price, as set out in is solar worth it. It's genuinely marginal on a shaded or north-only roof, but for most decent roofs the lifetime maths is positive.

"They'll damage or leak my roof"

Panels mount on rails fixed to the rafters, with flashing or proprietary hooks to keep the weatherproofing intact. A competent MCS install does not cause leaks, and the array can actually shelter the tiles beneath it. The real maintenance items are bird mess and leaf debris around the edges, not water ingress.

"You need a south-facing roof"

South is the textbook best case, but east and west roofs are very workable, generating maybe 10 to 15% less in total while often matching your morning and evening use better. Many homes do well splitting panels across two faces. The orientation question is part of is solar worth it.

"Solar needs constant cleaning and upkeep"

At a normal roof pitch, rain keeps panels largely clean, and there are no moving parts in the array itself. The one scheduled cost over the system's life is usually a single inverter replacement at 10 to 15 years, budgeted in how much solar costs. An occasional visual check and clearing obvious debris is about the extent of it.

"You must have a battery for solar to pay"

A battery is a separate decision, not a requirement. Panels often have the stronger standalone payback, and storage earns its place only when your usage pattern or tariff lets it cycle hard, which is exactly what do I need a battery works through. Plenty of worthwhile systems have no battery at all.

"The panels degrade fast, and there's no payment for export anymore"

Two myths in one. Quality panels lose about 2% in year one, then around 0.5% a year, so they still make roughly 87% of their original output at 25 years. And while the old Feed-in Tariff closed in 2019, the Smart Export Guarantee replaced it: you're still paid for every unit you export, at rates that reach about 20p with the best suppliers.

"Making the panels is worse for the planet than they save"

The energy used to manufacture a panel is repaid by the energy it generates in roughly one to three years, depending on the technology and where it was made. Over a 25-year-plus life, a panel produces many times the energy that went into building it, and the carbon balance follows the same shape. It's a fair question to ask, and the numbers answer it clearly in solar's favour.

"They're useless in a power cut, so what's the point?"

True, but it's the wrong point. For safety, a grid-tied system shuts down in an outage so it can't backfeed the network while engineers are working on it. The point of solar isn't backup, it's cutting your bills every day the grid is up. If outage protection matters to you, it's a specific battery feature to ask for, covered in do I need a battery, not a reason to skip panels.

"It's not worth it because I might move"

Two things soften this. A paid-for solar system is generally treated as an asset by buyers and surveyors rather than a liability, so part of the cost can be reflected in the sale price. And the savings start immediately, so even a few years of lower bills offset a real share of the outlay before you go. Whether it adds up for your timeline is, again, a numbers question rather than a rule of thumb.

"Prices will drop, so it's better to wait"

Panel prices have fallen for years and may keep drifting down, but two things push the other way. Energy you don't generate now is energy you buy at the full rate in the meantime, and the 0% VAT on domestic installs is set to return to 5% after 31 March 2027. Waiting shaves a little off the hardware while costing you the bills you'd have avoided. The better question usually isn't "will it be cheaper later", it's "what am I paying the grid while I wait".