Solar Panels on an East-West Roof in the UK: Are They Worth It?

These are general comparisons. Shading, roof pitch and local weather can have a greater effect than orientation alone.

Do east-west solar panels work in the UK?

Solar photovoltaic panels generate electricity from daylight rather than heat. They continue producing electricity in cloudy weather, although their output is lower than in strong, direct sunlight.

Roof direction changes how much electricity is generated and when that electricity becomes available. It does not determine whether the panels work.

Energy Saving Trust describes an unshaded south-facing roof as ideal but confirms that east- and west-facing roofs remain suitable. It also warns that shading may have a larger effect than orientation. An unshaded east-facing slope could therefore outperform a south-facing slope heavily shaded by trees, chimneys or nearby buildings.

MCS performance calculations account for the property’s location, panel orientation, roof pitch and shading. Under the MCS convention, due south has an azimuth of 0°, while due east or west has an azimuth of 90°. Your quotation should show separate estimates for the east- and west-facing sections rather than one unexplained generation figure.

What generation pattern should you expect?

An east-facing array starts generating earlier and is strongest before midday. A west-facing array begins more slowly but continues producing further into the afternoon and early evening.

Together, the two roof slopes create a wider and generally flatter generation profile than a south-facing system. This can be useful for households that consume electricity at several points throughout the day rather than mainly around lunchtime.

Electricity used while the panels are generating normally reduces the amount purchased from the grid. Electricity that is not used or stored can be exported.

In Great Britain, the Smart Export Guarantee allows eligible small-scale generators to receive payments for electricity exported to the grid. Electricity suppliers set their own rates, contract periods and conditions, so tariffs should be compared carefully.

An east-west system can generate over a long period during summer. In winter, output from every UK solar installation falls because days are shorter and the sun is lower. A south-facing roof normally has an advantage during this period, so request monthly forecasts rather than relying solely on an annual total.

Inverters, strings and shading

East and west roof slopes receive different levels of sunlight at the same time. The electrical design must accommodate that difference.

A common approach is a string inverter with separate maximum power point tracker, or MPPT, inputs. These allow roof sections with different orientations to be controlled independently.

Manufacturers also offer inverter configurations designed for multiple roof orientations. Fronius, for example, explains that multiple MPPTs can accommodate east-west arrays and differently sized roof sections.

Microinverters or power optimisers may be appropriate where there are:

• Several roof faces
• Unequal panel groups
• Chimneys or rooflights
• Unavoidable partial shading
• A requirement for panel-level monitoring

They are not automatically necessary for every east-west installation. Their additional cost should be supported by a clear design benefit. Energy Saving Trust notes that optimisers can reduce the effect of individual shaded panels, but may not increase generation on an otherwise unshaded roof.

Ask your installer how many panels will be fitted to each slope, whether the orientations have independent tracking, how shading has been calculated and whether the monitoring platform separates the two roof sections.

How to choose the right east-west solar system

1. Survey both roof slopes

   Measure the usable area and identify chimneys, valleys, rooflights, aerials and seasonal shading.

2. Understand your electricity use

   Morning-heavy homes may benefit from greater east-facing capacity. Homes with higher afternoon consumption may benefit from more west-facing panels.

3. Compare several layouts

   Ask for the maximum sensible panel layout and at least one smaller alternative. More generation is useful, but the largest system is not automatically the most financially attractive.

4. Check the roof condition

   Repair ageing tiles, felt, battens or flat-roof coverings before installing equipment expected to remain in place for decades.

5. Review the inverter design

   Confirm how each orientation is managed and whether the proposed inverter will support a future battery.

6. Compare warranties properly

   Review panel product warranties, performance warranties, inverter cover and the installer’s workmanship guarantee. Establish who handles a claim if equipment fails.

7. Request an MCS performance estimate

   The estimate should use the property’s postcode zone, panel orientation, pitch and shade factor. MCS states that these variables must be considered when estimating output.

8. Assess lifetime value

   Consider self-consumption, export income, equipment replacement, maintenance and finance costs—not simply the first-year savings figure.

Costs, savings and payback

Energy Saving Trust’s current reference figure is approximately £7,600 for a typical 4.5kWp domestic solar installation. Battery storage commonly adds around £5,000–£8,000. Figures were checked in July 2026.

East-west pricing may be similar to a straightforward south-facing installation, although additional mounting, cabling, scaffolding complexity or power electronics could increase the quotation.