Best Direction for Solar Panels on Commercial Buildings in the UK

Choosing the optimal direction for solar panels is one of the most important decisions in any commercial solar installation. In the UK, where weather patterns, daylight hours, and roof design all play a part, aligning solar panels correctly can significantly affect the amount of electricity generated—and ultimately, the return on investment.

For businesses investing in solar energy, panel orientation isn’t just a technical detail—it directly impacts energy output, operational cost savings, and long-term sustainability targets. A poorly oriented system might underperform by as much as 20–30%, eroding financial benefits and delaying payback periods.

This guide explains how panel direction affects energy production, whether south-facing roofs are always best, and what businesses can do when they don’t have an ideal roof layout. Whether you are planning a new solar PV installation or reviewing an existing system, this article will help you make informed decisions.

Why Direction and Tilt Matter in Solar Panel Performance?

Understanding the best direction for solar panels is crucial to getting the most out of your system. Solar panels work by capturing sunlight and converting it into electricity. In the UK, the sun travels from east to west but is mostly positioned in the southern part of the sky. This means panels that face the right way—and are angled correctly—can generate significantly more power over the course of the year.

The ideal tilt angle varies depending on location, but for most UK commercial properties, a tilt between 30° and 40° provides a good balance across seasons. The right combination of direction and tilt can maximise performance and shorten payback periods.

Note: This chart is based on simulated estimates derived from typical UK solar irradiance data and industry best practices. Actual output may vary depending on location, roof conditions, shading, and technology. For accurate site-specific projections, consult tools like PVGIS.

What’s the Optimal Direction for Solar Panels in the UK?

South-facing roofs are widely considered the best direction for solar panels in the UK. The sun travels across the southern part of the sky, providing south-facing panels with the most consistent and direct sunlight throughout the day—especially during midday, when solar generation typically peaks. When installed correctly and without any shading, south-facing panels can deliver up to 100% of their theoretical energy output, making them the gold standard for system performance.

That said, not all commercial buildings have a south-facing roof, and other orientations can still be highly effective. For example:

East-facing panels tend to perform well during the morning hours and can generate around 80–85% of the output of a south-facing array.
West-facing panels are stronger in the afternoon and perform similarly to east-facing systems.
North-facing panels receive the least direct sunlight in the UK and usually generate about 60–70% of the output compared to south-facing panels. However, they may still contribute meaningfully in systems with large roof areas, low pitches, or when supplemented with bifacial panels.

East-West Facing Roofs: A Strong Alternative for Commercial Sites

Many commercial roofs, especially large warehouses and industrial buildings, have east-west orientations. While they may not provide the best direction for solar panels in terms of total peak output, east-west orientations offer several advantages for commercial users.

This setup can extend the energy generation window across more daylight hours—catching the sun in the morning (east) and late afternoon (west). This aligns well with typical business operating hours and provides a more consistent output curve, reducing reliance on grid electricity during the day.

Note: This chart is based on typical UK solar generation profiles for south-facing and east-west panel orientations. Values are illustrative and may vary depending on location, weather, and installation specifics. For precise figures, professional modelling tools like PVGIS are recommended.

Can Solar Panels Work on North-Facing Roofs in the UK?

When discussing the best direction for solar panels, north-facing roofs are often seen as the least favourable. In the UK, north-facing panels receive the least direct sunlight and may generate as little as 60–70% of what a south-facing array would produce.

That said, it’s not always a deal-breaker. If the roof has a low pitch (10–15°), or if bifacial solar panels are used (which collect sunlight from both sides), north-facing roofs may still contribute meaningfully. Businesses with large roof areas may find installing panels across multiple directions worthwhile.

Solar carports or ground-mounted systems can provide a viable alternative when the roof isn’t suitable.

Other Key Factors That Impact Panel Direction and Performance

a. Roof Shape and Pitch

The shape and pitch of your roof can influence the best direction for solar panels. Flat roofs, standard on many commercial buildings, offer flexibility as panels can be mounted on angled brackets facing south—even if the roof itself doesn’t face that way.

On pitched roofs, the existing angle and orientation are more restrictive. In these cases, a solar designer must assess whether the current slope can be used effectively or if alternative mounting solutions are needed.

b. Shading and Obstructions

Shading from nearby buildings, trees, chimneys, or HVAC units can significantly affect performance—even if you’ve chosen the best direction for solar panels. A thorough shade analysis is essential during the design stage. Sometimes, adjusting panel layout or removing obstructions can unlock more output.

c. Local Climate and Regional Differences

The UK’s weather varies by region. Southern parts of England typically receive more sunlight than northern Scotland, which means output can differ by 10–15% depending on location even when using the best direction for solar panels. Still, solar PV remains viable across all parts of the UK.

Adjusting for Non-Ideal Roof Directions

Not every commercial property can offer the best direction for solar panels, but there are ways to overcome this:

Mounting systems: Flat roofs allow panels to be tilted toward the south regardless of the roof direction.
Mixed orientations: Splitting the array across different sections (e.g., east and west) can balance energy generation throughout the day.
Smart technologies: Modern inverters with Maximum Power Point Tracking (MPPT) optimise performance even when panels face different directions.
Battery storage: Storing excess energy during peak sunlight hours can increase system value, especially if production is spread throughout the day.

South is Ideal, But Not Always Essential

To sum up, the best direction for solar panels in the UK is generally south-facing, as it captures the most sunlight throughout the day. This orientation offers the highest potential output and the quickest return on investment. However, not every commercial building has a south-facing roof—and that’s okay. With expert design, east- and west-facing panels can still deliver excellent performance, especially when aligned with a business’s energy usage patterns.

Factors such as roof pitch, available space, shading, and regional climate conditions all play a role in determining the most effective setup. The key is to design a system that works with your site, not against it.

At EvoEnergy, we combine technical knowledge, real-world experience, and in-depth assessments to recommend the most efficient and cost-effective solar solutions for commercial properties across the UK—regardless of roof orientation. If you’re ready to find the best direction for solar panels on your building, try our Solar Panel Calculator to estimate your potential savings, or contact our team for a free expert consultation.