I notice that commercial businesses are asking this question more often now than they were two years ago. And I think that's actually a sign of maturity in the market.
Have the easy wins been taken?
The roofs that were obvious candidates for solar have already been fitted. What's left are the genuine questions: the ones where the numbers aren't obvious, where the payback period stretches beyond five years, where the business has to weigh up competing priorities.
So let me be honest about what I see.
Commercial solar in 2026 is still worth it for most businesses. But it's not worth it for all of them.
And the difference between the two often comes down to three things: your energy consumption profile, your available roof space, and whether you've got the capital or can access decent finance.
The case for solar: it's still strong
Here's what I notice when I look at the numbers. A typical mid-sized commercial building, let's say a 5,000 square metre warehouse or office, can fit around 50 to 100 kilowatts of solar capacity on its roof. In the UK, that'll generate somewhere between 40,000 and 80,000 kilowatt hours per year, depending on location and shading. At current business electricity rates of around 25 to 35 pence per kilowatt hour, that's a saving of £10,000 to £28,000 per year. Before any other benefits.
Now, a 50kW solar installation typically costs between £40,000 and £60,000 installed. Many commercial systems currently achieve payback periods of around three to seven years, depending on installation costs, energy prices, usage profile and available tax incentives. After that, you've got another 20 to 25 years of essentially free'ish electricity. I think that's still a compelling return, especially when you factor in the fact that electricity prices have historically risen faster than inflation.
There's also the capital allowances angle. If you own the building and you're installing solar, you can claim 100% capital allowances on the cost in the year of installation. That means you can offset the entire capital cost against your corporation tax liability.
For a business in the 19% tax bracket, that's a tax saving of around £8,000 to £11,000 on a £40,000 to £60,000 installation. That effectively brings your net cost down to £30,000 to £50,000, which changes the payback period to between two and four years.
That's genuinely attractive.
Where solar gets tricky
But here's where I think the conversation gets more nuanced. If your building is heavily shaded, if your roof is in poor condition and needs replacing before you can install solar, or if you've already got a lot of south-facing glazing that's doing the cooling job for you, then solar might not be your best use of capital right now. I also notice that businesses with very flat load profiles, where they use electricity evenly throughout the day and night, don't get as much benefit from solar as businesses with daytime peaks. A warehouse that runs 24/7 will only use about a third of its solar generation in real time. The rest gets exported to the grid, and the export price is typically half the import price. So you're getting maybe 12 to 15 pence per kilowatt hour for the excess, rather than the 25 to 35 pence you're saving on the electricity you would have imported.
That's not a deal breaker. But it does mean the payback period stretches out. And if you're a tenant rather than an owner, you've got the additional complication that you can't claim capital allowances, and you might not have landlord consent to install solar in the first place.
The finance question
I think this is where the real shift is happening in 2026. Five years ago, you had to have the capital to install solar. Now, you don't. There are several routes to finance a solar installation without putting a charge on your property or tying up your working capital.
You can lease the system.
You can get an unsecured loan.
You can use a solar PPA where a third party owns the system and you buy the electricity at a fixed rate.
Each of these has different implications for your balance sheet, your tax position, and your cash flow. But the point is, the lack of upfront capital is no longer a barrier.
And I think that's changed the economics significantly. If you can finance a solar installation over seven years at a cost that's lower than your current electricity bill, then you've got an immediate cash flow benefit from day one. You're not waiting for a payback period. You're saving money from month one.
My take
I think commercial solar is still worth it in 2026 for most businesses. The technology is mature, the costs have stabilised, and the finance options are now genuinely competitive.
The question isn't really "is solar worth it?" anymore. The question is "is solar the best use of my capital right now, or should I be looking at LED lighting, heat pumps, or power factor correction first?"
For a lot of businesses, the answer is that solar is still the best starting point. It's visible, it's understood, and it's got a clear financial case. But I'd encourage you to think about it as part of a broader energy efficiency strategy, not as a standalone project.
Are you considering a solar project for your commercial building right now?
Whether you're wondering if the numbers stack up, or you're trying to figure out how to fund it without straining your cash flow, we can help.
At Locataire Energy Capital, we work with businesses to find the right finance structure for solar installations and other energy efficiency projects.
Get in touch to discuss your specific situation and we'll walk you through the options.