Do Solar Panels Have to Face South to be Worth it in the UK?

Solar panels get a lot of coverage these days and mostly there’s a prediction in there for how much you can earn on a South facing roof. But what if you don’t have a South facing roof? What if your roof faces South East, should you still be looking at solar and will it still pay? What if your roof faces straight West? Is it still worth investigating solar panels? and can the Feed in Tariff still pay enough to be worth it? The simple answer to these is yes but read on for the facts and figures.


Do you have to have a South facing roof to have solar panels?

In the UK, South facing panels will generate more than other orientations. Solar panels perform at their best when the sun is shining straight on to the panels. When the sun shines onto the surface at an angle, the panel will still generate electricity but it will be less effective. The sun moves from East to West during the day and is higher or lower in the sky depending on the season (lower in winter, higher in summer). This means that for most roof mounted systems the sun will be at an angle for the vast majority of the time. The optimum placement to maximise generation is to face the panels South but that might not be possible for your property.

We ran a few calculations and found that SE and SW facing placements can expect to generate around 94% of the electricity a South facing install would. That’s much better than most people would guess and even an East / West facing roof can generate around 80% of the maximum. We assumed a 40° elevation for the roof. At lower pitches, say 30°, the East / West facing panels perform slightly closer to South. At higher pitches, the difference increases.

An example of a South West facing roof

Here’s a quick example of a South West facing roof in London.

Electricity Generated 3,501 kWh
FiT Income £468.78
Export Income £84.90
Electricity Savings £272.71
First Year Income & Savings £826.39

This SW facing example in London outperforms the generation we (and DECC) use when we model returns from well sited solar in the UK. The predicted generation is marginally more than a similar but South facing system would generate in Edinburgh, for instance.

The direction your panels face is certainly a factor in how much they will generate and closer to South is better but it is only one factor. If your roof faces slightly off South or even straight East / West it is still very likely that solar PV could generate savings and income for you. To get an accurate picture of generation potential, savings and income you would need a site assessment from accredited installers. As always, we recommend that you get information and quotes from 3 or more installers to ensure you get the right products, the right service and the right price for your project.

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