Why Commercial Solar Panels Are a Smart Investment for UK Offices in 2025

September 5, 2025

Do your office energy bills keep climbing month after month? Commercial solar panels could be the answer your business needs. UK companies are achieving returns on investment ranging from 16% to 45%, with most systems paying for themselves within 4 to 7 years, depending mainly on electricity prices and the amount of solar energy used on-site [5].

The financial benefits are clear. A typical 20kW solar system can save your business more than £4,595 a year on electricity and reduce carbon emissions by about 9.9 tonnes. You can also earn extra income through the Smart Export Guarantee, which pays for any surplus electricity you send back to the National Grid.

Yes, the upfront investment ranges from £16,000 to £70,000 for small to medium-sized enterprises [9], but a £50,000 commercial system could deliver £8,000 in annual electricity savings, plus an additional £2,000 through SEG payments [9]. The Annual Investment Allowance also allows businesses to claim 100% first-year capital allowances [9].

Before you decide to install commercial solar panels in 2025, make sure you understand the costs involved.

Understanding the Cost of Commercial Solar Panels

The cost of commercial solar panels depends on several factors that affect both your upfront spending and long-term savings.

Things like system size, panel efficiency, how complex the installation is, and where your business is located all affect the final price. Learning about these factors early helps you make smart choices and get the most value over the system’s 25-year life.

Average cost by system size

System capacity drives pricing more than any other factor. Small to medium-sized businesses typically invest between £16,000 and £70,000 for commercial solar installations [10]. Here’s how costs break down by system size:

System size	Average cost (including VAT)	Typical panel count
10 kWp	£12,780	30
25 kWp	£31,950	75
50 kWp	£63,900	150
100 kWp	£127,800	300

A key benefit of commercial solar is that bigger systems are cheaper per kilowatt. In 2025, the average installation costs about £5,763, or £1,312 per kW. For example, a 50kW system might cost £200,000 to £250,000, and a 200kW system could be £700,000 to £800,000 [10].

Average Glo Renewables Cost by system size

Here’s how costs break down by system size:

System size	Average cost range (including VAT)	Typical panel count
10 kWp	£7,500 – £13,000	30
25 kWp	£15,000 – £28,000	75
50 kWp	£30,000 – £70,000	150
100 kWp	£75,000 – £125,000	300

A key benefit of commercial solar is that bigger systems are cheaper per kilowatt. In 2025, the average installation costs about £1,150, or £750 per kW.

Factors that influence pricing

System size tells only part of the story. Several other elements shape your final investment:

Panel efficiency and type – Monocrystalline panels offer superior efficiency to polycrystalline alternatives [32]. These high-efficiency options generate more power from limited roof space, potentially maximising returns over time [11].
Installation complexity – Your roof’s condition, accessibility challenges, and any structural reinforcement needs directly impact labour costs [5]. Flat commercial roofs typically provide the most cost-effective installation environment [32].
Mounting options – Ground-mounted systems require more investment than rooftop installations due to the additional costs of land preparation and concrete foundations [32]. Floating mounting systems for water bodies offer unique advantages but command premium pricing [5].
Geographic location – Installation and labour costs fluctuate across UK regions [5]. Local planning requirements and regulations can also influence project timelines and overall costs.
Scaffold requirements – Safe access for installers is almost always necessary. The type, duration, and complexity of scaffolding will significantly influence project costs [11]. A straightforward two-storey domestic property may only need standard perimeter scaffolding, while larger or more complex installations (such as churches, schools, or commercial buildings) can require extensive, multi-level scaffold with protective sheeting, increasing both hire duration and expense.

Cost breakdown by component

Knowing where your money goes can help you make better decisions. Here’s how costs are usually split in a commercial solar project:

Solar panels: 25-40% of total cost [5]
Inverters and batteries: 10-20% of total cost [5]
Mounting/racking systems: 10-15% of total cost [5]
Labour and installation: 15-20% of total cost [5]
Electrical work: 5-10% of total cost [5]
Energy management systems: 5-10% of total cost [5]

Standard inverters cost £500-£1,500 and typically last 10 years [5]. Systems using 14 panels with microinverters add roughly £2,500 to project costs [5].

Since commercial solar prices have dropped in recent years [10], 2025 is a great time to consider solar for your business.

How Much Can UK Offices Save with Commercial Solar Panels?

Picture your office making its own electricity, cutting monthly bills, and even earning money from extra power. Many UK businesses are already seeing these financial and environmental benefits with solar.

Annual savings by system size

System capacity determines your potential savings, and the numbers tell an encouraging story for small to medium-sized businesses:

System size	Estimated annual savings
10kW	£2,435
20kW	£4,595
50kW	£11,895
60kW	£14,325
80kW	£24,055
100kW	£27,030

This table is an illustrative example only. The assumptions used are as follows: import price, 22p/kWh; self-consumption, 80%; export rate, 8p/kWh (SEG); and annual generation, 900 kWh/kWp. Actual results vary by tariffs, usage patterns, and site yield.

These numbers show real long-term value. For example, a medium-sized business using about 25,000 kWh a year could save around £3,750 each year [5]. Some UK businesses have even cut their electricity bills by 50% to 80% after installing solar [5].

Break-even timelines on Commercial Solar Panels

Commercial solar installations typically deliver faster returns than residential systems, which often require 5-7 years to recoup costs [9]. Most commercial systems reach break-even within 4-7 years [9], although this timeframe can be extended depending on system specifications.

Several factors drive this rapid return:

Businesses face higher electricity prices without residential caps
Commercial operations typically consume more energy during daylight hours
Larger systems benefit from economies of scale

The size of your system affects how quickly you break even. A 20kW system usually pays for itself in 4 to 5 years, while a 100kW system might do so in just 2 to 5 years [32]. After that, your business can enjoy free electricity for the next 20 years or more.

Commercial solar systems offer about a 16% profit [11], making them appealing compared to many traditional investments.

Impact of energy usage patterns

When your business uses electricity makes a big difference to your savings. Companies that operate primarily during the day benefit most from solar energy, as they can utilise the power as it’s generated instead of sending it to the grid [5].

Businesses with operations concentrated between 9am-5pm, typical office hours, stand to gain maximum value. However, businesses with peak energy demands during evenings or nights (such as logistics hubs or cold storage facilities) might export most of their solar production at lower rates than they pay for imported electricity [5].

Seasonal variations in energy consumption also influence savings. Retail businesses experiencing higher winter demand may see different returns than operations with consistent year-round consumption [5]. Geographical location plays a role too; southern England receives more sunlight than northern regions, affecting generation capacity throughout the year [5].

It’s also important to think about future growth. If your business plans to expand or use more energy, your original solar system might cover less of your needs over time, which could change your return on investment [5].

Using as much of your solar power on-site as possible brings the most savings, since exporting usually pays less than what you pay to buy electricity from the grid [5].

What to Know Before Installing Solar Panels on Commercial Buildings

Your office might seem perfect for solar panels, but a few practical details will decide if the installation works well. Looking into these early can save you money and help you avoid issues later.

Roof space and panel count

Commercial rooftops aren’t created equal when it comes to solar potential. Office buildings with flat roofs have a distinct advantage, they accommodate mounting systems that position panels at optimal generating angles [12]. South-facing roofs capture maximum sunlight throughout the day, though east or west-facing orientations still work well [12].

Your roof’s structural integrity is the most important factor. It must safely support both panels and mounting equipment. A thorough structural survey during the feasibility assessment reveals whether reinforcement is necessary [12].

Calculating your panel requirements starts with knowing your annual energy consumption in kilowatt-hours (kWh). Here’s the straightforward formula: Energy Needs ÷ Output per Panel = Number of Panels [12]

Consider a building that uses 50,000 kWh annually, with a single panel producing 400 kWh yearly. You’d need roughly 125 panels [12]:

50,000 kWh / 400 kWh = 125 panels.

Space requirements are equally important: commercial installations typically need about 100 square feet per kilowatt of solar power [13], with each standard panel occupying approximately 2 square metres [4].

Commercial Solar Panels – Installation process overview

Every successful installation begins with a thorough feasibility study that examines your site’s potential. Our surveyors check roof orientation, shading problems, and structural capacity to determine the best system size [14].

Once designs are approved, physical installation follows a logical sequence: scaffolding preparation, mounting system installation, panel placement, inverter connections, component wiring, and monitoring system configuration [4]. Most projects finish within 1-2 weeks ~100 kW is commonly reported, but the overall project (surveys, DNO, approvals, commissioning) often runs into several weeks. [15]. As of August 2025 Glo Renewables have found this wait to be over 6 weeks, depending on region.

The good news is that almost all the work takes place on your roof, so your daily operations won’t be disrupted much, if at all. You’ll only have a short power outage when the system is connected to your distribution board [4].

Maintenance and cleaning needs – Commercial Solar Panels

Solar panels earn their reputation for low maintenance throughout their 25-30 year lifespan [6]. Cleaning every 12-18 months helps maintain optimal performance by removing dust and dirt that block sunlight absorption [6].

British weather helps here; rain naturally cleans panels angled at 15 degrees or more [16], particularly during winter months [17]. Panels near trees need extra attention, though. Keep branches well-trimmed to prevent leaves from covering your panels [6].

Professional cleaning costs depend on your system’s size and location. At Glo, we offer solar cleaning and maintenance. Just contact our team to find out more.

Annual maintenance inspections remain very worthwhile. They satisfy insurance requirements, protect warranties, and ensure you receive the maximum return on your investment [15].

Legal and Planning Considerations for UK Offices

It’s important to know the rules for commercial solar installations. Sorting out the legal side early can help you avoid delays and keep your project moving smoothly.

When planning permission is required

Several specific situations trigger the need for formal planning permission. Any commercial solar installation exceeding 1 megawatt capacity in England and Wales requires a full application [18]. Systems between 50kW and 1MW need Prior Approval, a streamlined process compared to full planning permission [18].

Size isn’t the only consideration. Planning permission becomes mandatory when installations might significantly alter your building’s external appearance or impact local amenities [18]. Ground-mounted commercial solar arrays exceeding 9 square metres also require planning consent [19].

As ever, if you have any questions or queries regarding any aspects of what’s discussed in this guide, please do give the Glo Renewables team a call: 01803 446101. We’d be happy to chat through.

Permitted development rights

Most standard commercial solar installations are considered “permitted developments,” so formal planning applications are not needed [18]. The UK government introduced these rights to encourage the adoption of renewable energy [1]. Your installation must meet these criteria:

For most non-domestic rooftops, solar is permitted development (no 1 MW cap) subject to conditions, e.g., no more than 200mm projection, and on flat roofs, the array must not exceed 1 m above the roof plane with appropriate edge setbacks. Although Glo have heard that there are some changes coming into force that could allow flat dormer roofs some flexibility on the 200mm protrusion.

Stand-alone (ground-mounted) arrays within a site’s curtilage are permitted once up to 9 m²; larger or additional arrays require planning permission. Extra restrictions apply in conservation areas and on listed buildings; always check with your Local Planning Authority [30].

Check with your local planning authority first; permitted development rights can be removed through Article 4 directions [20].

Special cases: conservation areas and listed buildings

Properties in conservation areas are subject to stricter rules. Planning permission is mandatory for any installation visible from highways or public spaces [21], even when the system meets all other permitted development criteria.

Listed buildings present additional challenges. You’ll need both planning permission and listed building consent before installation begins [22]. Your application must prove that panels won’t damage the structure or significantly alter the building’s historical character [23].

Installations within the grounds of listed buildings or on scheduled monuments always require formal consent [24]. Expect six to eight weeks for approval in these special cases [23].

At Glo Renewables, we’ve built strong relationships with a wide network of planning consultants and specialists who understand the challenges of installing solar in sensitive areas. Whether your property sits within an Area of Outstanding Natural Beauty (AONB), holds listed status, or falls under stricter local planning controls, we have access to dedicated planners who can guide applications through smoothly. Our team works closely with these experts to ensure compliance with all regulations, while still achieving the best possible design and outcome for your installation.

Available Solar Grants and Incentives in the UK

As we explain in our Solar Panel Grants UK guide, financial support schemes across the UK make it easier for businesses to adopt solar panels. Government incentives help lower installation costs and can create new revenue opportunities, improving your return on investment.

Smart Export Guarantee (SEG)

Since January 2020, the SEG has required electricity suppliers to pay businesses for surplus renewable electricity fed into the National Grid. This scheme offers flexibility that its predecessor, the Feed-in Tariff, couldn’t offer; you can shop around for the best export rates, currently ranging from approximately 3.02p to 15.1p per kWh [36][37].

Your installation needs to meet these criteria for SEG eligibility [36]:

System capacity under 5MW (50kW for micro-CHP)
MCS certification or equivalent standards
Smart metre capable of half-hourly export readings [25]

Annual Investment Allowance (AIA)

Tax benefits through the AIA make solar investments particularly attractive for UK businesses. Companies can deduct 100% of qualifying expenditures from taxable profits within the year of purchase [39]. Currently fixed at £1 million with no scheduled end date [27], this allowance effectively reduces your upfront investment through immediate tax relief [39]

Local authority and regional grants

Regional programmes complement national schemes, offering targeted support across different areas:

Scotland’s Non-Domestic Rates Relief exempts new solar installations from business rates until 2035 [29]
Wales provides the Green Business Loan Scheme with funding between £1,500 and £1.5 million [29]
Great British Energy recently launched a £200m fund specifically for schools and hospitals [30]

Each region has its own opportunities, so it’s a good idea to check with your local council about what programmes are available [31].

What Devon Offers: Local Grants & Green Funding (2025 Edition)

When it comes to regional support for commercial solar installations in Devon, several funding streams are currently available across different districts:

Green Impact Fund (Devon & Torbay), 2024/25 (now closed)

This £1.8 million capital grant scheme, created under the Devon & Torbay Devolution Deal, offered £5,000–£49,999 for decarbonisation projects (up to 80% for revenue-generating businesses and 100% for non-profits). Applications closed on 29 November 2024, and all awards had to be spent by 31 March 2025.

Mid Devon Green Enterprise Grant

Open for 2025, Mid Devon District Council offers SMEs capital grants between £500 and £5,000, covering up to 50% of project costs. Eligible projects include renewable energy systems (like solar), energy efficiency upgrades, and resource-saving measures. Applications must be fast to implement, with total project budgets capped at £30,000 including VAT. The deadline is 31 December 2025; however, the scheme may close early if funds are exhausted.

East Devon Carbon Action Fund

Also known as the CAF, this scheme offers funding to both businesses and community organisations in East Devon. Eligible investments, such as solar PV, heat pumps, insulation, and LED lighting, can be supported up to £30,000, with a minimum application of £2,000. Businesses must contribute at least 30% match-funding, while community groups need only contribute 10%. All funds must be claimed and spent by 31 March 2026.

Teignbridge Green Business Grant (UK Shared Prosperity Fund)

Part of a £165,000 allocation from the UK Shared Prosperity Fund, this Teignbridge scheme helps businesses invest in solar, low-energy heating, thermal insulation, LED lighting, and more. It can cover between 80% and 100% of project costs, depending on business type.

What This Means for You

Wide coverage across Devon: Whether you’re based in Mid Devon, East Devon, Teignbridge, or even across Devon & Torbay, there’s likely a scheme that suits your business.
Strong support for solar: Each program includes renewable energy sources (such as solar PV) among eligible investments.
Significant savings potential: With grants covering up to 100% of costs, these schemes can substantially reduce capital outlay.
Time-sensitive opportunities: The Green Impact Fund deadline has passed, but others (like Mid Devon and East Devon) are ongoing; act quickly!

Green loans and solar financing options

Specialist green business loans provide favourable terms for renewable energy projects. Major banks, including Barclays offer discounted interest rates for eligible green assets like solar panels [7]. Asset finance options also allow businesses to spread costs over time whilst preserving working capital [8].

With these financing options, upfront costs don’t have to stop your business from enjoying the long-term benefits of solar.

How Glo Renewables Supports Your Solar Journey

With more than 80 five-star reviews, Glo Renewables makes it easy and stress-free to switch to commercial solar power. From your first enquiry to installation and aftercare, our team handles everything, including site assessment, system design, installation, and maintenance planning.

We tailor each solar PV system to match your building’s energy needs, helping you get the best value and long-term reliability. Our MCS-certified installers ensure you meet UK regulations and can access incentives like the Smart Export Guarantee and Annual Investment Allowance. Whether your business is large or small, Glo Renewables provides a full solar solution that saves you money and supports your sustainability goals.

Frequently asked questions about commercial solar panels

How much can UK offices save by installing commercial solar panels?

UK offices can save significantly with solar panels. A typical 20kW system can reduce annual electricity bills by over £4,595, while larger systems of 100kW can save up to £27,030 per year. The exact savings depend on factors like system size, energy consumption patterns, and location.

What is the average payback period for commercial solar panels in the UK?

Most commercial solar panel systems in the UK reach break-even within 4 to 5 years. However, larger systems may achieve faster returns, with some breaking even in as little as 2 years. After this period, businesses essentially enjoy free electricity for the remaining 20+ years of the system’s lifespan.

Do UK offices need planning permission to install solar panels?

In most cases, commercial solar installations qualify as “permitted developments” and don’t require formal planning permission. However, planning permission is necessary for systems exceeding 1 megawatt capacity, installations in conservation areas, or on listed buildings. It’s always best to consult your local planning authority beforehand.

What financial incentives are available for UK businesses investing in solar panels?

UK businesses can benefit from several incentives, including the Smart Export Guarantee (SEG), which pays for surplus electricity exported to the grid, and the Annual Investment Allowance (AIA) offering 100% tax relief on qualifying expenditure. Additionally, some regions offer specific grants and green loan schemes with favourable terms.

How much maintenance do commercial solar panels require?

Commercial solar panels require minimal maintenance. Regular cleaning every 12-18 months is typically sufficient to maintain optimal performance. Rain naturally cleans tilted panels in the UK, but professional cleaning may cost between £20 and £200, depending on system size. Annual inspections are recommended to satisfy insurance requirements and protect warranties.

Written by Glo Renewables LTD with the support of AI tools to refine and structure content.
Reviewed by: Charlie Yabsley – August 2025