South vs east-west facing solar panels
"You need a south-facing roof" is the single most common reason people talk themselves out of solar, and it's only half true. South is the textbook best case for total output, but it isn't the only good option, and it isn't always the one that saves you the most money. East and west roofs are genuinely worthwhile, and for some households they beat south on the figure that actually matters. Here's how the directions really compare.
What south-facing gives you
A south-facing array captures the most sun across the day, so it produces the highest annual total for a given number of panels. That's why it's used as the baseline for solar estimates. If your goal is maximum generation from limited roof space, south wins.
What east-west gives you
An east-west split puts some panels facing the morning sun and some facing the afternoon. The total over a year is typically 10 to 20% lower than the same panels facing south. But the shape of the day changes: instead of one midday peak, you get a broader curve with a morning and an evening shoulder. For a household that uses power at breakfast and after work, that curve lines up with demand far better.
| Orientation | Annual output (relative) | Generation shape |
|---|---|---|
| South | 100% (baseline) | One strong midday peak |
| East-west split | ~80 to 90% | Morning and evening shoulders |
| East or west only | ~80 to 85% | Half-day peak |
| North only | ~65 to 75% | Weak, usually not worth it alone |
The figures are approximate and shift with pitch and location, but the ranking holds across the UK.
Why the lower-output roof can win
The catch with south is that its midday peak often arrives when nobody's home to use it, so a lot of it gets exported at the lower rate. East-west generation, spread into the morning and evening, is more likely to be used as it's made, which is worth more than exporting it. That gap between using a unit (worth about 25p) and exporting it (worth about 15p) is the whole reason self-consumption matters, as set out in solar panel payback. A roof that produces a bit less but at the right times can beat one that produces more at the wrong times.
Splitting across two roofs
An east-west home often has two usable faces, which means you can fit more panels than a single south slope would allow. More panels at 85% each can out-generate fewer panels at 100%, and the flatter curve pairs well with a battery, which has more hours to soak up surplus. The battery side is covered in are solar batteries worth it.
What about north?
A north-only roof is the one orientation where the case is genuinely weak: output drops enough that payback stretches a long way. North-facing panels as part of a larger east-west-north spread can still add something, but a north slope on its own is usually the point where the honest answer is "probably not worth it." It's the grain of truth inside the "you must face south" myth, unpicked in solar panel myths.
The detail most people miss
Orientation interacts with shading, and the two are easy to confuse. A perfectly south-facing roof shaded by a tree from 3pm can underperform an unshaded west roof, because shade hits output harder than direction does. So assess them together, not in isolation, the way solar panels and shading describes. Direction sets the ceiling; shade decides how close you get to it.
Frequently asked questions
No. South gives the most total output, but east and west roofs generate only about 10 to 20% less and often match your usage better, which can mean similar or better savings.
Often yes. They spread generation across morning and evening, so more of it is used at home rather than exported cheaply, and a split roof can fit more panels.
South for maximum generation; east-west for a better match to typical household demand. The best choice depends on your roof and when you use electricity.
A north-only roof is the weakest option and usually marginal on payback. As part of a larger multi-direction array it can add a little, but on its own it's rarely worth it.