Whether solar panels are right for your house depends on five things — and your neighbour's roof is probably not the same as yours. Two houses on the same street can get results that differ by thousands of pounds over the life of a system, simply because of how their roofs face, who is at home during the day, and what they currently pay for electricity.
This guide walks through each of those five factors honestly. For some homes, solar is a genuinely strong investment. For others, the numbers just don't stack up — and it's worth knowing the difference before you invite a salesperson round.
Why do two houses on the same street get such different results from solar?
The short answer is that solar output and savings depend on your specific roof, your household's electricity habits, and your financial situation — not your postcode alone. A terraced house with a north-facing roof, a chimney casting shade, and a family who are out from 8am to 6pm will get far less from a solar system than a detached neighbour with a clear south-facing roof and someone at home all day. Let's break down each factor.
Factor 1: Which way does your roof face?
Roof direction is the single biggest technical variable, and it's one your neighbour has no influence over for you. The Energy Saving Trust consistently notes that south-facing roofs produce the most electricity in the UK, because the sun tracks through the southern sky here all year round.
In practical terms, south-east and south-west are nearly as good — they lose only around 5% of output compared with due south. East- or west-facing roofs produce roughly 80–85% of what a south-facing roof would, which still makes them viable in most cases. A purely north-facing roof is the one orientation where solar rarely makes financial sense: north-facing panels typically generate only 50–60% of a south-facing system's output, meaning payback times stretch considerably.
If you have roof space on both an east and a west face, a split array can actually work well — you generate electricity across a longer daily window, from morning through to evening, which helps with self-consumption. See our guide on solar panels on an east-west roof for the full picture.
Not sure which way your roof faces? Stand inside looking out of a window on that roof slope and check which compass direction you are facing — that is your roof's orientation.
Factor 2: Is your roof shaded?
Shade is solar's worst enemy, and it doesn't take much of it to dent your system's output. A single chimney, a tall neighbouring tree, or a dormer window casting shadow across your panels for even part of the day can reduce generation significantly — particularly with older string-inverter systems, where shade on one panel can pull down the whole array.
Modern micro-inverters and power optimisers help manage partial shade much better, but they add cost. If your roof is heavily shaded for large parts of the day, no amount of technology fully compensates. An honest installer should carry out a shading assessment before recommending a system — if one doesn't, that's a red flag. Our guide to solar panels and shade explains exactly how trees and chimneys affect output, and what can be done about it.
Factor 3: How big is your electricity bill?
This is the factor people talk about least, but it matters enormously. Solar panels save money by reducing the electricity you buy from the grid — so the more you currently spend on electricity, the more there is to save.
Under Ofgem's price cap for July–September 2026, the average unit rate is 26.11p per kWh. Every unit your panels generate and you use yourself saves you that amount. Surplus electricity you export to the grid earns you a separate payment under the Smart Export Guarantee (SEG) — flat-rate SEG tariffs currently pay around 4p to 15p per kWh depending on the supplier, with some time-of-use tariffs paying more at peak times.
The Energy Saving Trust puts typical savings for a home with a 3.5kWp system at up to around £610 a year, though some households save less and some save more — the difference comes down to the factors in this article. To put it plainly: if your annual electricity spend is relatively low (say, under £600 a year), there is less headroom for solar to work with, and payback will take longer. If your bill is high — particularly if you have an EV, a heat pump, or work from home — solar has much more to save you.
A worked example: a typical 3-bedroom home with a 4kWp south-facing system might save somewhere in the range of £500–£850 a year on bills plus export income, based on current electricity prices and SEG rates. That's a range, not a guarantee — your actual saving will depend on every factor in this article.
Factor 4: When are you at home?
Solar panels generate electricity during daylight hours, not when you need it in the evening. This means households that use electricity during the day — because someone works from home, there are young children, or you run appliances on a timer — get far more value from solar than households who are out all day.
Every unit you use directly from your panels saves you the full import rate (currently around 26p per kWh). Every unit you export earns you far less — perhaps 12p per kWh on a decent SEG tariff. Self-consumption is therefore worth roughly twice as much as export. A household that self-consumes 40–50% of its generation will see meaningfully better returns than one exporting most of what it produces.
If you are out from 9am to 5pm every day, solar can still be worth it — you just need to be realistic about the numbers, and a battery becomes a more compelling addition. Without a battery, exporting households will see savings at the lower end of the range. For a full look at how your daily routine interacts with solar, see our piece on solar panels if you're out all day.
Factor 5: What is your financial situation?
Solar panels are a capital investment. A typical domestic 4kWp system costs somewhere in the region of £6,000–£9,000 fully installed in 2026 (the range reflects panel quality, installer, roof complexity, and location). Based on Energy Saving Trust figures, it could take a typical home at least 10 years to recoup installation costs under current electricity prices — though homes with high daytime usage and good roof orientation can do better than that.
That payback period only works if you plan to stay in the house long enough to benefit. If you are likely to move in the next three to four years, the maths is harder, though solar can add value when you sell. If paying upfront is difficult, there are now finance options — but borrowing adds cost. Check our guide on how to pay for solar panels monthly for an honest rundown of the options.
One current financial advantage worth knowing about: solar panels are installed at 0% VAT until 31 March 2027, under HMRC's energy-saving materials relief (VAT Notice 708/6). After that date the rate is due to rise to 5%. On an £8,000 system that is a meaningful saving, and it is worth factoring into your timing.
So — should you follow your neighbour?
Possibly, but only if your own house passes the test. Ask yourself honestly:
- Does my main roof face south, south-east, south-west, east, or west (not north)?
- Is my roof reasonably free from shade for most of the day?
- Is my annual electricity spend high enough to make meaningful savings?
- Is someone at home during the day, or am I willing to add a battery?
- Am I planning to stay in this home for at least seven to ten years?
If you can answer yes to most of those, your house is likely a decent candidate and it's worth getting proper quotes. If you answered no to several — a north-facing roof, heavy shading, a very low electricity bill, moving soon — be cautious. An honest installer will tell you the same.
Your neighbour's system might be working brilliantly for them. Whether it works for you is a separate question — and the only way to find out properly is to have your specific roof and usage assessed.
FairSolar connects homeowners with vetted, MCS-certified local installers who will give you a realistic picture — including if solar doesn't make sense for your home. If you'd like free, no-obligation quotes tailored to your property, get started here. There's no pressure and no commitment.
Frequently asked questions
How do I know if solar panels are right for my house?
Check five things: your roof's direction (south, east, or west is workable; north usually isn't), whether your roof is shaded, how large your electricity bill is, whether you use electricity during the day, and whether you plan to stay in the property long enough for the investment to pay back. If most of those are in your favour, it's worth getting a proper survey and quotes from MCS-certified installers.
My neighbour has solar panels and loves them — does that mean they'll work for my house too?
Not necessarily. Two houses on the same street can get very different results if their roofs face different directions, one has more shade, or the households use electricity at different times of day. Your neighbour's experience is a useful data point, but your home needs its own assessment.
Why do some houses get better results from solar than others?
The main reasons are roof orientation (south-facing performs best), shading from trees or chimneys, how much electricity the household uses during daylight hours, and the size of the electricity bill overall. A household with a south-facing unshaded roof and high daytime electricity use will typically get much better returns than one with a shaded east-facing roof where everyone is out all day.
Is solar worth it if I'm out at work all day?
It can be, but you'll export more electricity to the grid rather than using it yourself — and export rates (around 4p–15p per kWh) are worth less than the electricity you avoid buying at around 26p per kWh. Adding a battery helps by storing daytime generation for evening use, though that adds to the upfront cost. The savings will typically be at the lower end of the range compared with a household at home during the day.
Does it matter how big my electricity bill is before going solar?
Yes — a lot. Solar saves money by replacing electricity you'd otherwise buy from the grid. If your annual electricity spend is already very low, there's less headroom for savings and the payback period stretches. Homes with higher bills — especially those with EVs, heat pumps, or someone working from home — generally see the strongest financial case for solar.