Commercial solar PV (photovoltaic) is a solar panel system designed to generate electricity at large scale, meeting the power needs of commercial sites.

It works by converting daylight into usable power for your building, helping to reduce electricity bills, lower carbon emissions and protect against rising energy costs. Systems are typically installed on commercial rooftops or unused land and are larger than domestic solar installations.
Any surplus electricity can be exported to the grid under the Smart Export Guarantee (SEG), regulated by Ofgem.

Commercial solar also supports the UK’s wider net zero strategy, led by the Department for Energy Security and Net Zero. For businesses with suitable roof space and daytime energy use, commercial solar PV can provide long-term cost savings and greater energy independence.

A commercial solar PV system typically has a lifespan of 25–30 years or more.

Most solar panels come with performance warranties guaranteeing around 80–85% output after 25 years. Inverters usually have a shorter lifespan (10–15 years) and may need replacing during the system’s lifetime.

In the UK, systems installed by an Microgeneration Certification Scheme (MCS) certified contractor such as Eltom Electrical must meet recognised quality and performance standards.

With proper design, quality components and routine maintenance, commercial solar is considered a long-term, low-maintenance investment for businesses.

In many cases, planning permission is not required for commercial rooftop solar in England, as it often falls under permitted development rights.

However, permission may be required if:

• The building is listed
• The site is in a conservation area or World Heritage Site
• The installation significantly alters the building’s external appearance
• It is a large ground-mounted solar array

Permitted development rules are set out by the Planning Portal.

Planning rules can vary in Scotland, Wales and Northern Ireland, so requirements should always be confirmed with the local planning authority before installation.

There are several ways UK businesses can fund a commercial solar PV installation:

1. Outright purchase
   Paying upfront provides the highest long-term return, as your business benefits from all energy savings and export payments.
2. Asset finance or loans
   Solar can be funded through commercial loans or asset finance, allowing you to spread the cost while benefiting from immediate bill savings. Guidance on business finance options is available from the British Business Bank.
3. Power Purchase Agreement (PPA)
   A third party installs and owns the system on your roof. You purchase the electricity generated at a reduced, fixed rate, with no upfront capital cost. These apply to large-scale installations with an output of at least 100 kWp.

Businesses may also be able to claim capital allowances on qualifying equipment under guidance from HM Revenue & Customs.

The right option depends on your cash flow, tax position and long-term energy strategy.

No — solar panels themselves do not use electricity. They generate electricity from daylight using photovoltaic (PV) cells.

However, the wider system includes components such as inverters and monitoring equipment, which use a very small amount of electricity to operate. This consumption is minimal compared to the energy the system produces.

In simple terms, a commercial solar PV system is designed to generate far more electricity than it consumes, helping your business reduce reliance on grid power.

The 120% rule is a UK grid connection guideline that limits how much solar generation can be connected to an existing electrical supply without upgrading the main distribution board.

In simple terms, the total of:

The rating of your main fuse + the solar system breaker must not exceed 120% of the busbar rating of your distribution board.

This rule is commonly applied under the Engineering Recommendations managed by the Energy Networks Association (ENA), particularly within G98/G99 grid connection standards:

For commercial installations, this assessment forms part of the grid application process. If the 120% threshold is exceeded, system design adjustments or electrical upgrades may be required.

Modern commercial solar panels in the UK typically operate at 15–22% efficiency, meaning they convert that percentage of sunlight into usable electricity.

• Panel type (monocrystalline panels are usually more efficient than polycrystalline)
• Orientation and tilt of the roof
• Shading from nearby buildings or trees
• Weather and seasonal sunlight levels

Even at 15–22% efficiency, a well-designed commercial system can generate significant electricity, reduce bills, and deliver a strong return on investment.

Commercial solar PV systems are low-maintenance. Typical upkeep includes:

• Cleaning panels occasionally to remove dust, bird droppings, or debris
• Visual inspections for damage or shading issues
• Checking inverters and electrical components annually

Most systems are designed to operate reliably for 25+ years with minimal intervention.

Eltom Electrical offers comprehensive maintenance packages for solar systems, meaning you can rest assured that all components in the system are operating safety and at full capacity, whilst ensuring the maximum lifespan for the overall system.

Yes — solar panels still generate electricity in cloudy or overcast conditions, though output is reduced compared with bright sunlight.

In the UK, panels can produce 30–70% of their typical output on cloudy days, depending on the thickness of the cloud cover and panel efficiency. Modern commercial systems are designed to work effectively even in less sunny climates.

Solar panels generate Direct Current (DC) electricity from sunlight.

A device called an inverter then converts this DC into Alternating Current (AC), which is the type of electricity used by your business, appliances, and the UK grid.

Yes, VAT applies to commercial solar PV installations, but there are some considerations:

• Exceptions: Some specific, limited exceptions exist, such as solar panels for certain charitable purposes or qualifying agricultural projects.

• VAT Reclaim:If your business is VAT-registered, you can usually reclaim the VAT on your quarterly return, making it a cash flow consideration rather than a permanent cost.
• Tax Reliefs:While VAT is charged, businesses can often benefit from 100% relief on the capital cost of solar panels through the Annual Investment Allowance (AIA), allowing the cost to be deducted from taxable profits

Yes — most commercial solar PV systems in the UK are grid-connected.

They use electricity on-site first, and any surplus can be exported to the grid under the Smart Export Guarantee (SEG), allowing businesses to earn payments for excess power.

More information from Ofgem.

Yes, solar panels can be recycled in the UK, with up to 95% of materials being reusable – improving the overall sustainability credentials of this technology.

When installed correctly by an accredited, experienced installer, commercial solar panels should not damage roofing.

Eltom Electrical will always complete a structural roof survey to confirm roof integrity and identify any additional reinforcement measures required prior to installation of a solar PV system.        

Yes, incorporating solar PV into your commercial property can increase its value.

• For sales: Energy-efficient buildings with lower running costs are often more attractive to buyers, potentially increasing market value, often by 5-10%, with some studies suggesting up to 30% higher premiums for sustainable, energy-efficient buildings.
• For rentals: Businesses may be willing to pay higher rents for properties with lower electricity bills and a strong sustainability profile.

Commercial solar can therefore provide long-term financial and environmental benefits while supporting property value.

In the UK, a well-designed commercial solar PV system will typically achieve an annual ROI between 10% and 25%, with many systems, especially larger ones (>100 kWp), yielding 20-33%.

Payback periods are generally fast, ranging from 3 – 7 years, depending on energy usage, electricity prices, system size, and roof orientation.

After this payback period, the system generates essentially free electricity, reducing bills and potentially earning from exporting surplus power under the Smart Export Guarantee (SEG).

Using an experienced, accredited installer helps maximise ROI by ensuring the system is efficient, reliable, and eligible for incentives.

Yes — you should notify your insurer before installation.

Adding a commercial solar PV system can affect your property insurance, as it changes the building’s structure and value. Notifying your insurer in advance ensures the system is properly covered for damage, theft, or liability once installed.

Using an accredited installer with MCS certification (Microgeneration Certification Scheme) such as Eltom Electrical, can also help satisfy insurer requirements.

Commercial solar PV systems carry a very low fire risk when installed by an accredited, experienced installer.

Certified installers follow strict safety standards, use quality components, and ensure proper wiring and inverters, all of which minimise the risk of electrical faults. MCS-certified systems are designed to meet UK fire and electrical safety regulations.

With professional installation and regular maintenance, solar panels are considered a safe, long-term energy solution.

Solar panels can generate electricity in almost any location, including the UK, because they work in daylight, not just direct sunlight.

Output is highest in sunny regions, but even in cloudier areas, modern commercial PV systems can produce 30–70% of their rated output. Proper design, panel orientation, and an experienced installer ensure the system is optimised for your specific site.

Commercial solar PV systems in the UK must comply with several key standards to ensure safety, performance, and eligibility for incentives:

• MCS (Microgeneration Certification Scheme): Certifies installers and equipment meet UK quality and safety standards.
• BS EN 62446 / BS 7671: Electrical safety and wiring standards for PV systems.
• G98/G99 (ENA): Grid connection standards for small and large-scale generation.
• Planning and building regulations: Depending on location, building type, and system size.

Using an accredited, experienced installer ensures your system meets all these requirements, is safe, and performs efficiently over its lifetime.