For many UK businesses, energy is one of the largest ongoing operating costs.
That makes the roof above your head more than just part of the building. It could be an opportunity to generate your own electricity, reduce your reliance on the grid and make a measurable difference to your annual energy costs.
Commercial solar has moved well beyond being simply a sustainability investment. When properly designed around a business’s energy consumption, it can deliver a strong financial return alongside long-term carbon savings.
But the numbers need to stack up.
So, what does commercial solar actually cost? How much could your business save? And how long could it take to pay for itself?
What Does Commercial Solar Cost in the UK?
There is no single price for a commercial solar installation.
System size, roof type, access, electrical infrastructure, panel specification, inverter selection, grid connection requirements and the complexity of the installation can all affect the final cost.
As a broad guide, commercial solar projects can vary considerably depending on the size and specification of the system. Larger installations generally benefit from economies of scale, meaning the cost per kWp can reduce as system size increases.
For example, a smaller commercial installation might cost tens of thousands of pounds, while a larger warehouse or manufacturing facility could require an investment of £100,000 or more.
A professional feasibility assessment should therefore look beyond the headline cost per kWp.
The important question is:
What Will The System Deliver For Your Business Over Its Lifetime?
A commercial solar proposal should consider:
- System size and expected annual generation
- Your historic electricity consumption
- Your future energy use, is your energy usage likely to change?
- Your current electricity tariff
- How much solar electricity you can use on-site
- Potential income from exported electricity
- Roof condition and available roof space
- Electrical infrastructure and grid connection requirements
- Maintenance and long-term performance
- Financing options
This gives you a much more meaningful picture of the investment than simply looking at the installation cost.
How Much Can Commercial Solar Save?
The biggest financial benefit of commercial solar comes from self-consumption.
Every unit of electricity generated by your solar system and used directly by your business is electricity you don’t need to purchase from the grid.
This is particularly valuable for businesses with significant daytime electricity demand.
Warehouses, manufacturing facilities, distribution centres, food production sites, cold stores and other commercial premises can often make strong use of solar generation because their operations continue throughout daylight hours.
The amount you can save depends on your individual site.
A business using a large proportion of its solar generation on-site will generally achieve a stronger financial return than a site where most of the electricity is exported.
That’s why we don’t believe in simply quoting a generic “solar saving”.
The right commercial solar system is one designed around how your business actually uses energy.
What Happens to Electricity You Don’t Use?
Your solar system won’t necessarily generate electricity at exactly the same time as your business needs it.
At times when solar generation exceeds on-site demand, surplus electricity can be exported to the grid.
Eligible generators can receive payment for exported electricity through the Smart Export Guarantee (SEG), although the rate offered depends on the supplier and tariff. Ofgem confirms that SEG licensees determine their own tariff rates, contract terms and other conditions, with mandatory participation applying to qualifying suppliers.
However, export income shouldn’t be the main reason for installing commercial solar.
In most cases, the strongest financial opportunity is to maximise the amount of solar electricity your business uses itself.
That is why understanding your site’s energy profile is so important.
Commercial Solar and Tax
Tax treatment can also form part of the overall business case.
In 2026, Solar PV is classified by HMRC as special-rate plant and machinery.
For qualifying companies, solar expenditure that is not fully covered by the Annual Investment Allowance (AIA) may be eligible for the 50% first‑year allowance, subject to the applicable conditions. Visit the gov.uk website for the most up-to-date guidance.
The tax position will depend on your business circumstances, accounting treatment and the specific project, so businesses should speak to their accountant or tax adviser before making assumptions about the benefit available.
It’s another reason why the headline installation price isn’t the whole story.
What Does Commercial Solar ROI Look Like?
There is no universal commercial solar payback period.
A realistic calculation needs to use your actual electricity consumption, tariff, proposed system size, expected generation, self-consumption and export assumptions.
For illustration, consider a business installing a 100 kWp commercial solar system.
If the system generates around 90,000 kWh per year, and the business uses 75% of that generation on-site, around 67,500 kWh could be used directly.
If those units would otherwise have been purchased from the grid at 28p per kWh, the avoided electricity cost would be approximately:
67,500 kWh × £0.28 = £18,900 per year
The remaining 22,500 kWh could potentially be exported, generating additional income depending on the export arrangement.
This is an illustration rather than a guaranteed return. Actual generation, electricity prices, self-consumption and export income will vary from site to site.
And that’s exactly why a proper solar feasibility assessment matters.
What Has the Biggest Impact on Your Solar Return?
There are several factors that can significantly affect the financial performance of a commercial solar system.
1. How Much Electricity You Use During the Day
This is one of the most important factors.
If your business operates during daylight hours and has a consistent electricity demand, you may be able to use a large proportion of your solar generation directly.
That means more of the electricity you generate offsets electricity you would otherwise have purchased from the grid.
2. Your Current Electricity Tariff
The value of every unit of self-consumed solar is linked to the electricity cost it replaces.
If grid electricity prices rise, the potential value of each unit of solar generation also increases.
This is one reason businesses should look at commercial solar as a long-term energy strategy rather than simply a short-term response to current prices.
3. Your Roof
Available roof area, orientation, pitch, shading and structural suitability all influence the size and performance of a solar installation.
South-facing roofs can provide excellent solar generation, but east-west roof configurations can also work particularly well for commercial buildings.
An east-west system can spread generation across more of the working day, which may actually suit a business with a consistent daytime load.
There isn’t a single “perfect” roof.
The right design depends on the building and how the business operates.
4. Your Electricity Demand Profile
Two businesses with identical roofs could achieve very different financial results from the same solar system.
Why?
Because they may use electricity very differently.
That’s why we analyse consumption data alongside the building itself when designing a commercial solar system.
What About Battery Storage?
For some businesses, battery storage can complement commercial solar.
A battery can store surplus electricity generated during periods of high solar production and make it available later when the business needs it.
This can potentially increase the amount of solar energy used on-site and reduce reliance on electricity from the grid.
However, a battery isn’t automatically the right solution for every business.
The financial case depends on factors including:
- Your electricity consumption profile
- Solar generation
- Existing import and export tariffs
- Peak demand
- Battery size and operating strategy
- Available space
- Grid connection requirements
The best approach is to assess solar and battery storage together rather than adding a battery simply because it is available.
How Can You Finance Commercial Solar?
You don’t necessarily need to fund a solar project entirely from your existing cash reserves.
Depending on your circumstances, there are several potential routes to consider.
Outright Purchase
Buying the system outright gives your business ownership of the asset from day one.
Once the system has paid for itself, the electricity it continues to generate can provide ongoing financial benefits for the remainder of its operational life.
An example illustration of how pay monthly options can fund your commercial solar project.
Asset Finance
Asset finance can allow businesses to spread the cost of a solar installation over an agreed period rather than paying the full amount upfront.
For projects with a strong financial return, the relationship between monthly finance payments and projected energy savings can make this an attractive option.
Actual terms and affordability will depend on the business, project and finance provider.
Power Purchase Agreements
Under a Power Purchase Agreement, a third party can fund and own the solar installation, with the business purchasing the electricity generated by the system at an agreed rate.
This can reduce the need for upfront capital investment, although the commercial terms and long-term benefits differ from an outright purchase.
The right financing structure depends on your business, cash position, tax circumstances and investment objectives.
Is Commercial Solar Right for Your Business?
There is no simple electricity bill threshold that makes commercial solar automatically worthwhile.
A business with a £20,000 annual electricity bill might have an excellent solar opportunity.
Another business with the same annual spend might have a poor one.
It comes down to the building, the roof, the electricity demand and the economics of the project.
The businesses most likely to benefit are those with:
- Suitable roof space
- Significant daytime electricity consumption
- A long-term interest in the property
- Meaningful electricity costs
- A desire to reduce exposure to future energy price increases
- A clear financial and sustainability strategy
And if you’re renting your premises, that doesn’t necessarily rule solar out. Landlord permissions and lease arrangements need to be considered, but there are still options worth exploring.
Commercial Solar Is a Financial Decision
The strongest commercial solar projects don’t start with a panel count.
They start with the numbers.
How much electricity does your business use?
When do you use it?
How much could solar generate from your roof?
How much could you consume directly?
What happens to the surplus?
What is the projected payback?
And what does the investment look like over 10, 20 or 25 years?
Once you have those answers, you can make a much more informed decision.
At CEMA Energy Group, we look at the whole picture.
From your energy consumption and roof space through to system design, projected generation, savings, payback and finance options, our aim is to show you exactly what commercial solar could mean for your business.
Ready to See What Your Roof Could Deliver?
A commercial solar system should be designed around your business — not a generic calculation.
Book a free, no-obligation solar feasibility consultation with CEMA Energy Group.
We’ll assess your site and energy requirements and show you the potential system size, generation, financial savings, projected payback and available options.
Your roof could be doing more than keeping the rain out.
