What’s the Best Roof Orientation for Solar Panels on UK Commercial Buildings?

The best roof orientation for solar panels in the UK is due south, at a pitch of roughly 30–40°. The sun sits in the southern half of the sky all year, so south-facing panels generate the most electricity annually. For commercial buildings, though, the most profitable orientation is the one that matches when your site uses power. East-west arrays on flat roofs often deliver the strongest return per square metre.

Key Takeaways

• South is the best roof orientation for maximum annual output in the UK, ideally at around 30–40° pitch. South-east and south-west roofs lose only a small share of that output.
• East and west roofs produce roughly 15–20% less than south per panel, according to the Energy Saving Trust. They remain a strong commercial option.
• East-west layouts on flat roofs often fit more capacity than south-facing rows. This can raise total site generation and spread it across the working day.
• The most profitable orientation is the one that maximises self-consumption. Grid electricity costs businesses around 23–24p/kWh on average, while exported power earns far less.
• North-facing roofs typically produce around 55–65% of south at common pitches. They usually need careful modelling, or an alternative such as carports or ground mounts.
• Shading, roof structure and DNO export limits can affect returns as much as orientation, so assess them together.

What is the best direction for solar panels to face in the UK?

South is the best direction for solar panels to face in the UK if the goal is maximum annual generation. South-east and south-west roofs lose only a small share of that output. East and west roofs produce roughly 15–20% less, and north-facing roofs perform worst. On commercial sites, east, west and flat roofs can still produce strong financial returns.

The Energy Saving Trust describes an unshaded south-facing roof as ideal. It notes that east or west facing roofs still work, while it does not recommend panels on north-facing roofs, and that east or west systems typically receive around 15–20% less energy than a directly south-facing one. Energy Saving Trust

The takeaway for businesses is that “not south” rarely means “not viable”. The more useful question is how much output your specific roof can produce, and when.

How much output does each roof orientation produce?

The table shows typical annual output relative to an equivalent due-south array on a pitched roof, unshaded, at around 30–40° pitch.

All figures are indicative. Actual output depends on location, shading and system design.

Why does roof orientation affect solar panel output?

Roof orientation affects solar output because panels produce the most electricity when sunlight strikes them close to perpendicular. In the UK, the sun rises in the east, sets in the west and sits in the southern sky at midday throughout the year. A panel’s azimuth therefore determines how much direct sunlight it receives, and at what time of day. Two angles define a panel’s position:

• Azimuth (orientation): the compass direction the panel faces.
• Tilt (pitch or inclination): the angle between the panel and the horizontal.

Azimuth controls when a panel generates. South peaks at midday, east in the morning, west in the afternoon. Tilt controls how well the panel captures the sun’s changing height between summer and winter.

The UK’s frequently overcast skies also matter. A large share of the UK’s solar resource arrives as diffuse light scattered by cloud, which reaches panels from across the whole sky rather than from one direction. This is why east- and west-facing arrays still perform well in the UK, and why the penalty for being off-south is smaller than many buyers expect.

What is the best tilt angle for solar panels in the UK?

For most UK commercial sites, the best tilt angle for solar panels is around 30–40° from horizontal. The optimum rises slightly further north, because the sun sits lower in the sky at higher latitudes. Output is forgiving across a wide range of pitches, so an existing pitched roof rarely needs special frames to correct its angle.

Analysis of MCS irradiance data places the optimal tilt at typically 37–38° in southern England, rising to 39–43° in northern England, Scotland and Northern Ireland. The penalty for missing that exact figure is small. Pitches from around 15 to 50 degrees still deliver over 90% of the theoretical maximum for a given orientation.

What tilt should panels use on a flat commercial roof?

On flat commercial roofs, panels are usually mounted on low-tilt frames rather than at the theoretical 35–40° optimum. Steeper angles increase wind loading, need heavier ballast and require wider gaps between rows to avoid self-shading. A lower tilt lets designers fit more capacity on the same roof and keep structural loads manageable.

MCS treats flat roofs as those below 10° to the horizontal. The standard sets specific requirements for ballasted systems:

• Wind pressure coefficients must be taken from BRE Digest 489 or recognised test data. 
• A qualified structural engineer must confirm the roof can carry the load of both the PV system and the ballast.

Flat roofs give designers a genuine choice of orientation, independent of which way the building faces. EvoEnergy’s solar output calculator reflects this: it offers separate roof-type options for flat roofs with south-facing modules and flat roofs with east/west-facing modules.

Are east-west facing solar panels a good choice for commercial buildings?

Yes. East-west solar panels are often an excellent choice for commercial buildings, particularly warehouses, factories and logistics sites with large flat or shallow roofs. Each panel generates slightly less than it would facing south, but an east-west layout spreads generation across the working day and usually fits more capacity on the same roof.

East-facing panels generate more in the morning, while west-facing panels perform better in the afternoon and early evening. Combined, they produce a broader, flatter generation curve than a south array’s sharp midday peak. That shape aligns well with typical business operating hours from early morning to late afternoon.

Many industrial buildings have ridgelines running north-south, giving them naturally east- and west-facing roof slopes. On these buildings, an east-west array is often the most practical way to use the full roof.

Why can an east-west layout generate more from the same flat roof?

East-west layouts can generate more total electricity from a flat roof because panels are mounted back-to-back in low “tent” rows. This avoids the wide gaps south-facing rows need to stop one row shading the next. The roof holds more panels, so total generation can exceed a south-facing layout even though each panel produces less.

What tilt should panels use on a flat commercial roof?

Is south-facing always the best direction for a business?

No. South-facing panels produce the most electricity per panel, but a business earns most from solar when it uses that electricity on site. Self-consumed solar offsets the full retail price of grid electricity, while exported electricity earns much less. An orientation that matches your demand profile can therefore deliver better savings than one that simply maximises kWh.

The price gap is large:

• Retail (import) price: DESNZ’s Quarterly Energy Prices figures, published in June 2026, put the average non-domestic electricity price at 23.61p/kWh excluding Climate Change Levy for January to March 2026. 
• Wholesale price: the House of Commons Library reported the GB wholesale system average price at around 4.0p/kWh in late May 2026.
• Export tariffs: businesses can sell surplus through the Smart Export Guarantee, which covers solar PV installations up to 5MW total installed capacity. However, SEG licensees set their own rates and terms; the only requirement is that the rate is above zero.

This is why generation timing matters so much. A south-facing array on a site that is quiet at midday, such as a building with early shifts or evening operations, may export much of its peak output at a low rate. An east-west array, or a west-weighted design on a site with strong afternoon demand, can keep more generation on site. Pairing either design with commercial battery storage shifts midday surplus into periods when the site would otherwise buy from the grid.

Can solar panels work on north-facing roofs in the UK?

Solar panels can technically work on north-facing roofs in the UK, but output is significantly lower. It is often around 55–65% of an equivalent south-facing array at typical pitches, improving on very shallow roofs. North-facing arrays rarely justify investment on their own. They are more viable as part of a larger multi-orientation system, or on low-pitch roofs.

Pitch is the deciding factor. The shallower the roof, the more a north-facing panel behaves like a horizontal panel collecting diffuse light. The steeper the roof, the more it faces away from the sun. On the SAP radiation table, a north-east or north-west roof falls to about 60% on a steep 60° gable. Field data points the same way: one analysis drawing on a 2019 University of York study of 26 Yorkshire-based 4kWp arrays found true-north panels to be about 54% as effective as south-facing panels on average.

Bifacial panels are sometimes suggested as a fix for north-facing roofs. Their benefit depends on light reaching the rear of the module. When panels are mounted close to a roof surface, rear-side gain is limited. Bifacial modules tend to add more value on elevated structures such as solar carports and ground-mounted arrays.

If the only available roof space faces north, consider those alternatives before committing to a north-facing array. For roofs that sit between north and west, see our guide: Is It Worth Installing Solar PV on an NW-Facing Roof?

How much does UK location affect solar panel output?

UK location has a significant effect on solar output. Annual yield ranges from roughly 750 kWh per kWp in the Scottish Highlands to about 1,050 kWh per kWp in Cornwall, based on PVGIS satellite data. That is roughly a 30% difference between the best and weakest regions. Solar remains commercially viable across the whole UK.

The regional ranking puts Cornwall, Devon and Dorset at the top with 1,000–1,050 kWh/kWp, against a national average of around 900 kWh/kWp.

Regional variation is built into the formal UK estimating method. MCS divides the UK into 21 zones, each with its own irradiance values for every combination of pitch and orientation, selected by postcode. These values come from the European Commission Joint Research Centre’s Climate-SAF-PVGIS dataset.

What else affects solar performance besides orientation?

Shading, roof structure and grid connection capacity can all affect a commercial solar project as much as orientation. A perfectly oriented array loses value if it is shaded, if the roof cannot carry it, or if the local network cannot accept its export. Each should be assessed before orientation is finalised.

1. Shading and rooftop obstructions

Shading can outweigh orientation. The Energy Saving Trust notes that shading can have an even bigger impact than direction; a shaded south-facing roof may generate less than a fully sunlit east- or west-facing one. On commercial roofs, common culprits include:

• Adjacent buildings and trees
• Parapets
• Plant rooms and HVAC units
• Rooflights
• Telecoms equipment

Optimisers can reduce the impact of partial shading, so one shaded panel doesn’t drag down the output of the others. Under the MCS standard, shading is quantified as a shade factor, calculated using the MCS methodology in MGD 005 or an equivalent method, and applied to the performance estimate.

2. Roof structure, pitch and loading

Every roof needs a structural check before design is finalised. MCS requires a suitably competent person to confirm the roof structure can withstand the loads a PV system imposes. For metal-clad roofs, the sheet thickness and the cladding’s fixings must be checked against the extra wind uplift the system introduces.

Existing roof warranties also matter. Where the roof covering is under warranty, the warranty provider should be consulted on whether the installation would invalidate it.

3. Grid connection and export limits

Orientation interacts with your grid connection. Commercial systems must be notified to or approved by the Distribution Network Operator (DNO). The applicable procedures are EREC G98 for installations up to 16A per phase, EREC G99 above that, and EREC G100 where export is limited.

Where the DNO restricts export, a south-facing array’s midday peak is more likely to be curtailed. A flatter east-west profile, or the addition of battery storage, can reduce that lost generation.

How can businesses get the most from a non-ideal roof orientation?

Businesses can get strong returns from non-ideal roof orientations through design choices. The main ones are frame-mounting panels on flat roofs, splitting arrays across several roof faces, using inverters with multiple MPPT inputs, adding optimisers where shading exists, and pairing solar with battery storage. Where the roof is unsuitable, carports and ground mounts are alternatives.

• Frame mounting on flat roofs: tilt panels south or east-west regardless of the building’s footprint.
• Multi-orientation arrays: use east, west and south-west faces together to widen the generation window. Each orientation should connect to its own Maximum Power Point Tracking (MPPT) input, so each can operate at its own optimum.
• Optimisers or module-level electronics: limit losses on partially shaded sections.
• Battery storage: store midday or afternoon surplus for use later in the day, raising self-consumption. See commercial battery storage.
• Energy management: smart grid controls can schedule flexible loads, such as EV charging or refrigeration pre-cooling, into generation hours.
• Alternative sites: solar carports and ground-mounted arrays can be oriented freely when roof space is limited or badly aligned.

To estimate how much capacity your roof could hold, see how many solar panels can fit on your roof.

How do you assess the best orientation for your site?

The best orientation for a commercial site is found by comparing generation models against the site’s actual demand. That means measuring roof azimuth, pitch and shading, then modelling yield with recognised data. The resulting generation profile is set against half-hourly consumption, with structural and grid constraints checked alongside.

1. Gather half-hourly consumption data. Twelve months of half-hourly data shows when the site uses electricity: weekdays vs weekends, shift patterns, and seasonal peaks.
2. Measure azimuth and pitch. Use drawings, surveys or site measurement for every usable roof face.
3. Assess shading. Use a sun-path or 3D shading analysis covering all nearby obstructions across the year.
4. Model generation. For systems up to 50kWp, MCS sets the standard estimate as installed capacity (kWp) multiplied by the location-specific kWh/kWp value (Kk) and the shade factor (SF). Larger commercial systems are typically modelled in specialist simulation software using hourly irradiance data. 
5. Compare layouts. Run south, east-west and mixed options side by side on total generation, self-consumption and export.
6. Check structure and roof warranty. Confirm load capacity and ballast requirements before fixing the layout.
7. Check grid capacity. Establish whether the DNO will accept export, or whether an export limit applies.
8. Evaluate the business case. Compare savings, payback and finance options such as CAPEX, PPA or lease-to-own.

Which Roof Orientation Is Right for Your Business?

The right roof orientation for your business is the one that produces the most usable electricity at the times your site needs it. South-facing panels win on annual output, but on many commercial buildings an east-west or multi-orientation layout delivers equal or better savings. It fits more capacity, spreads generation across the working day and reduces low-value export.

For most commercial sites, the decision comes down to four questions:

1. When does your site use electricity? Half-hourly consumption data shows whether a midday peak or a broader morning-to-afternoon profile suits you better.
2. What does your roof allow? Pitched roofs largely fix the orientation. Flat roofs give you a genuine choice between south-facing and east-west layouts.
3. What limits the system? Shading, structural capacity and DNO export limits can outweigh a few degrees of orientation.
4. Where does the generation go? A layout that keeps more electricity on site, with or without battery storage, usually shortens payback more than one that simply maximises kWh.

A roof that doesn’t face south is rarely a reason to rule out solar. Choosing a layout from a rule of thumb rather than site data, however, is a common reason commercial systems underdeliver.

Find the best orientation for your building. Estimate your generation with our Solar Output Calculator, or make an enquiry for a site-specific feasibility assessment. Our engineers will compare south, east-west and mixed layouts against your actual energy demand, roof structure and grid capacity.

Which Roof Orientation Is Right for Your Business?

The right roof orientation for your business is the one that produces the most usable electricity at the times your site needs it. South-facing panels win on annual output, but on many commercial buildings an east-west or multi-orientation layout delivers equal or better savings. It fits more capacity, spreads generation across the working day and reduces low-value export.

A roof that doesn’t face south is rarely a reason to rule out solar. Choosing a layout from a rule of thumb rather than site data, however, is a common reason commercial systems underdeliver.

Find the best orientation for your building. Estimate your generation with our Solar Output Calculator, or make an enquiry for a site-specific feasibility assessment. Our engineers will compare south, east-west and mixed layouts against your actual energy demand, roof structure and grid capacity.

Frequently Asked Questions

What is the best direction for solar panels to face in the UK?

South is the best direction for solar panels to face in the UK for maximum annual generation, ideally at a 30–40° pitch. South-east and south-west roofs perform almost as well. East and west roofs generate roughly 15–20% less, but can suit businesses whose demand peaks in the morning or afternoon.

Do solar panels need to face exactly due south?

No. Solar panels do not need to face exactly due south. Roofs within about 45° of south, meaning south-east to south-west, typically achieve around 90–95% of due-south output. The difference is often smaller than the losses caused by a single shading obstruction.

Is east or west better for commercial solar panels?

Neither is universally better; it depends on when your site uses electricity. East-facing panels generate more in the morning, and west-facing panels more in the afternoon and early evening. Annual output is similar. Many commercial buildings use both faces as an east-west split to cover the full working day.

Are north-facing solar panels worth installing on a commercial building?

North-facing panels are rarely worth installing on their own on a commercial building. They typically produce around 55–65% of south-facing output at common pitches. They can make sense on very shallow roofs, or as part of a larger multi-orientation array, but should be modelled against carport or ground-mount alternatives first.

What is the best tilt angle for solar panels in the UK?

The best tilt angle for solar panels in the UK is around 30–40°, rising slightly further north. Output is forgiving: pitches between roughly 15° and 50° still achieve over 90% of the optimum for a given orientation. On flat roofs, lower tilts are common to reduce wind loading and fit more panels.

Does roof orientation affect solar payback?

Yes. Roof orientation affects solar payback because it changes both how much electricity is generated and when. A south-facing array produces the most kWh, but payback depends on how much generation the site uses directly. An east-west system with higher self-consumption can match or beat a south-facing system on payback.

Can battery storage make up for a poor roof orientation?

Battery storage cannot increase the energy a poorly oriented array generates. It can, however, increase the value of that energy by storing surplus for use later instead of exporting it cheaply. Batteries are most effective where generation and demand are mismatched in time, which is common on commercial sites.

How do I find out which way my commercial roof faces?

You can check your roof’s orientation using building drawings, satellite mapping or a compass reading on site. A formal solar design will measure azimuth (degrees from due south) and pitch for every usable roof face. It then models output for each, which is the most reliable way to compare options.