East-West vs South-Facing Solar Panels: Which Is Better?

In the UK, the sun is due south at midday and sits lower in the sky in winter, so a south-facing roof receives the most sunlight over a year. Typical annual output for a well-sited south-facing system is roughly 850 to 1,000 kWh per kW of panels, depending on location and shading.

Other orientations compare broadly as follows:

• South: the highest annual output
• South-east and south-west: only slightly less than south, often around 5% lower
• East and west: typically around 15% to 20% less than south
• North-east and north-west: considerably lower
• North: usually not worthwhile on a typical pitched roof

Roof pitch also matters. A south-facing roof at around 30 to 40 degrees typically performs best, while shallower pitches reduce the difference between orientations. On a low-pitched east-west roof, the penalty compared with south can be smaller than on a steep one.

These are typical figures. Shading from chimneys, trees and neighbouring buildings can matter more than orientation, and a good installer will model your specific roof rather than relying on general rules.

A south-facing system produces most of its electricity around midday, when many households are out and use relatively little. Much of that midday peak is exported, often for a few pence per kWh.

East and west-facing panels have a different daily pattern:

• East-facing panels: generate most in the morning, when households are getting ready for work or school, running kettles, showers and appliances.
• West-facing panels: generate most in the afternoon and early evening, when people return home and start cooking.
• Both together: produce a flatter, wider curve across the day, with less of a midday peak.

Because electricity you use yourself is worth the full import price, currently an average of 26.32p per kWh under the price cap from 1 October 2026, while exported electricity often earns much less, the timing of generation can matter as much as the total.

That is why an east-west system with somewhat lower total output can deliver more value per kWh generated than a south-facing system, depending on your household's routine and your export tariff.

Consider two 4kW systems on similar homes, each used by a household out at work during the day:

• South-facing: generates around 3,600 kWh a year. The household uses around 40% directly, about 1,440 kWh, and exports the remaining 2,160 kWh.
• East-west: generates around 3,000 kWh a year, about 17% less. Because more output arrives in the morning and evening, the household uses around 50% directly, about 1,500 kWh, and exports 1,500 kWh.

At 26.32p per kWh for electricity used at home:

• With a 4p export tariff: the south-facing system is worth about £465 a year, and the east-west system about £455 a year. The difference is just £10.
• With a 12p export tariff: the south-facing system is worth about £640 a year, and the east-west system about £575 a year.

The lower your export rate, the closer the two become, because the south-facing system's extra output is mostly exported. These figures are illustrative, but they show why east-west roofs should not be dismissed.

Many homes with east and west-facing roofs have the option of using both faces. That brings two benefits:

• More panels: a home that can fit eight panels on one face might fit 14 or 16 across both, significantly increasing total generation.
• A wider generation curve: output starts earlier in the morning and continues later into the evening, raising self-consumption.

Because the fixed costs of an installation, such as scaffolding, the inverter and electrical work, are largely the same whichever faces are used, adding panels on the second face often costs less per panel than the first.

The larger system may need a different approach to the grid connection. Systems with an inverter output above 3.68kW on a single-phase home supply need prior approval from the network operator, so many installers pair a larger east-west array with an inverter limited to 3.68kW. Because east and west panels rarely produce their peak output at the same time, that limit often causes very little loss.

Our guide to how many solar panels you need explains why the 3.68kW figure does not cap the number of panels.

An east-west system needs a slightly different design from a single-face system, and a few points are worth checking in any quote:

• Separate inverter inputs: panels on different roof faces should normally be connected to separate inputs on the inverter, known as MPPT inputs, so each face can operate at its best. Most modern string and hybrid inverters have at least two.
• Optimisers or microinverters: usually not essential for a clean east-west layout, but useful where one face is partly shaded or the roof has several sections.
• Inverter sizing: because east and west panels peak at different times, the inverter can often be smaller relative to the total panel capacity without much loss.
• Panel layout: hipped roofs, dormers and roof windows can limit the usable area on each face.

Ask each installer to show predicted generation for each roof face separately, along with expected self-consumption. That makes it easier to judge whether panels on both faces are worthwhile.

Our guide to solar inverters explains the different types and when optimisers or microinverters earn their cost.

Which orientation suits you best depends largely on when your household uses electricity:

• Out at work during the day: east and west panels generate more when you are at home, and west-facing generation in the late afternoon is particularly useful.
• At home during the day: south-facing panels suit you well, because you can use much of the midday peak directly.
• Early risers: east-facing panels match morning routines.
• Evening cooks and families with children: west-facing panels match afternoon and early evening demand.
• Electric car owners: the best orientation depends on when the car is at home to charge.

If you have a smart meter, look at your half-hourly or hourly usage pattern to see when you use most electricity. That tells you which generation pattern would be most valuable.

For many households, the answer is not one orientation or another but using whatever good roof space is available. A south-facing roof is ideal, but east and west-facing roofs can still deliver worthwhile savings.

Battery storage changes the comparison between orientations. A battery stores surplus solar for later use, so the timing of generation matters less.

With a battery:

• A south-facing system's midday surplus can be stored and used in the evening, reducing the advantage of east-west timing.
• An east-west system produces less surplus at midday, so a smaller battery may be enough.
• The total generation becomes more important, which can favour a south-facing roof or panels on both east and west faces.

Export tariffs matter too. On a high flat-rate export tariff, extra generation is worth more, which favours the orientation with the highest total output. On a low export tariff, using more electricity directly matters more, which narrows or removes the gap between south and east-west.

Time-of-use export tariffs that pay more in the early evening peak can favour west-facing panels, which generate later in the day, or a battery that stores solar for export at peak times.

Our guides to solar and battery costs and export tariffs explain these choices in more detail.

Some homes have no suitable south, east or west-facing roof. Options include:

• Flat roofs: panels can be mounted on frames angled towards the south, or in low-tilt east-west rows that fit more panels into the space. Flat roofs on extensions, garages and dormers are common locations.
• North-facing roofs: usually not worthwhile on a typical pitched roof, because output is considerably lower. On a very shallow pitch, the penalty is smaller, but the economics still need careful checking.
• Outbuildings and garages: garden buildings, garages and carports with better orientation can host panels, subject to cable routes and structural suitability.
• Ground-mounted arrays: possible in larger gardens, though planning rules and cost need checking.

A good installer will tell you honestly if your roof is unsuitable, rather than recommending panels that are unlikely to pay back.

Our guide to home solar panel costs explains how roof type and layout affect the price.

Shading often affects output more than orientation. A small amount of shade on part of a roof can reduce output across a whole string of panels unless the design accounts for it.

Common sources of shade on UK homes include:

• Chimneys and chimney stacks
• Dormer windows and roof extensions
• Neighbouring houses, especially on terraced streets
• Trees, which also grow over the 25-year life of a system
• Satellite dishes, aerials and vents

East and west-facing roofs are particularly sensitive to low sun in the early morning and late afternoon, when shadows from neighbouring buildings and trees are longest. In winter, those shadows can be much longer than they appear during a summer survey.

Ask installers how shading has been assessed for each roof face, and whether optimisers or a different panel layout would reduce losses. A roof that looks clear at midday in summer may have significant shading at the times when east or west-facing panels generate most.

A good shade assessment, covering the whole year, is the best way to judge whether a roof face is worth using.

When you ask installers to quote for an east or west-facing roof, check that each proposal shows:

1. Predicted annual generation for each roof face separately
2. Expected self-consumption, based on when your household is home
3. Inverter inputs, confirming each roof face has its own input
4. Whether optimisers or microinverters are proposed, and why
5. How shading from chimneys, dormers, trees or neighbouring buildings has been assessed
6. A comparison with alternative layouts, such as one face only or both faces
7. The price per kW and the expected value of the electricity, not just the output

Compare proposals on the value of the electricity you will use and export, not just the total kWh figure.

Our guides to how many panels you need, solar inverters and export tariffs cover the related decisions. When you are ready, compare quotes from up to three MCS-certified installers for your roof.