Powering Change
Installing since 2010 · 0118 951 4490 · info@spiritenergy.co.uk
Yes — for most businesses with daytime electricity use and suitable roof space. With grid electricity at 22–35p/kWh and solar generating at just 4–6p/kWh over its lifetime, any business spending £20,000 or more a year on electricity sees a strong return. Most Spirit Energy commercial systems pay back in 4–5 years and deliver a 20–35% IRR. Businesses that use most of their power during the day — manufacturers, warehouses, hotels, care homes, retail — see the strongest results, because they consume their own generation rather than exporting it at the lower rate. See the full benefits of commercial solar for more.
Commercial solar costs roughly £700–£1,100 per kWp installed in 2026. Larger systems cost less per kWp because the fixed costs — survey, scaffolding, electrical connection and commissioning — are spread across more panels. As a guide, a 50 kWp system runs around £40,000–£85,000, a 100 kWp system £75,000–£190,000, and systems above 250 kWp benefit most from economies of scale. For a full breakdown by system size, see our commercial solar cost, payback and ROI page.
A commercial solar system typically offsets 40–70% of daytime electricity consumption. The exact saving depends on system size, how much of your demand falls during daylight, and your current grid tariff. For a business spending £50,000 a year on electricity, a well-sized system can save £20,000–£35,000 annually. Savings come mostly from displaced grid imports — electricity you generate and use yourself instead of buying — rather than from exporting surplus, which pays a lower rate.
Commercial solar panels typically last 25–30 years or more. Quality Tier 1 panels carry a performance warranty of 25 years or longer and degrade only around 0.4–0.5% per year, so a system still produces roughly 85–90% of its original output after 25 years. The inverter is usually the only component you would expect to replace once, around the 10–15 year mark. With basic maintenance, a commercial array keeps generating well beyond its warranty period.
Most Spirit Energy commercial systems pay back in 3–5 years, and as little as 3 years where on-site daytime demand closely matches generation. Payback depends on system cost, how much generation you self-consume, and your grid electricity price — the higher your tariff and the more you use during daylight, the faster the return. After payback, the system generates effectively free electricity for the remaining 20-plus years of its life. Our cost, payback and ROI page covers this in full.
Recent Spirit Energy commercial projects have delivered internal rates of return (IRR) of 23–45%, with lifetime ROI regularly landing in the 400–700% range. Most of the return comes from displaced grid imports rather than export income. Because commercial electricity prices in the UK are currently around 118% above the European median and remain volatile, the savings — and therefore the ROI — tend to improve over the system's life as grid prices rise. See the full numbers on our commercial solar cost, payback and ROI page.
Commercial solar in the UK currently costs between £700 and £1,100 per kWp installed, including panels, inverters, mounting, cabling and commissioning. The figure falls as system size rises, because the fixed costs of a project — surveying, scaffolding, grid connection — don't scale with the number of panels. A small rooftop system sits at the higher end of that range; a large warehouse or ground-mount array at the lower end.
Usually not. Most commercial rooftop solar qualifies as Permitted Development in the UK. Listed buildings, properties in conservation areas, and most ground-mounted arrays may require a planning application. Spirit Energy assesses your site and handles any planning permission needed as part of the process, so you don't have to navigate it alone.
Yes — grid-connected commercial solar systems require approval from your Distribution Network Operator (DNO). DNO approval is needed to export electricity to the grid, and for larger systems to connect at all. Spirit Energy handles the full G99 application end-to-end, which typically takes 6–10 weeks for approval. We manage the process so your installation timeline stays on track.
Most commercial solar installations take 1–3 weeks on site, once approvals are in place. The full process runs through seven stages: free site assessment, a tailored proposal, the DNO grid application, planning where needed, installation, commissioning, and ongoing maintenance. Spirit Energy's in-house MCS-certified team handles every stage, and we work around your operating hours to minimise disruption to your business.
Disruption is minimal. Scaffolding is erected on external elevations only and does not affect day-to-day operations inside the building. Internal electrical work — connecting the system and commissioning — is planned around your working hours, and Spirit Energy works outside normal hours where needed. We have installed at fully operational sites including hotels, hospices, care homes and motorway service stations without requiring closures.
The main differences are scale and design. A home system is typically 4–6 kWp; commercial systems start around 50 kWp and can exceed 1,000 kWp. Commercial projects involve three-phase grid connections, DNO approval, structural surveys and careful load-profile matching to daytime business demand. Because businesses use more of their generation on site, a well-designed commercial system often delivers faster payback than a domestic one.
The best panels are Tier 1 monocrystalline modules selected for your specific project. Spirit Energy's 2026 commercial lineup includes AIKO, LONGi, REC and Viridian, each chosen for a particular project type based on efficiency, temperature coefficient, voltage and real-world UK performance. For large commercial rooftops we specify jumbo-format panels, where the larger physical size means fewer panels and a lower installation cost per kWp.
Sometimes, but not always. Without battery storage, typical commercial self-consumption is 30–40% of generated electricity; with a correctly sized battery it rises to 60–70%, capturing far more value from each unit generated. However, while commercial batteries are clearly the future, they remain expensive today and don't always stack up financially. Spirit Energy only recommends storage where the numbers genuinely work for your site.
Yes, through the Smart Export Guarantee (SEG). Under the SEG, businesses earn money by selling surplus electricity back to the grid, with suppliers setting their own rates — so it is worth shopping around for a competitive deal. For most commercial sites, though, the bigger saving comes from self-consumption rather than export, since the rate you save by not buying grid electricity is higher than the rate you earn for exporting.
Often, yes. UK businesses may qualify for a 50% First Year Allowance on solar PV, plus Annual Investment Allowance where it applies — meaningful first-year corporation tax relief on the system. Tax treatment depends on your individual circumstances and current legislation, so always verify with your accountant.
Yes. Commercial solar panels still generate electricity on cloudy days, just at a lower output than in full sun, which makes them well suited to the typical UK climate. System sizing already accounts for British weather and seasonal variation, so the projected savings in your proposal reflect real-world conditions across the year, not just sunny days.
Rarely on its own, and that is by design. Solar only generates during daylight, so it won't cover night-time demand without battery storage, and even then full energy independence is uncommon and rarely the most cost-effective goal. The aim of a commercial system is to maximise the return on investment — offsetting as much of your daytime grid import as makes financial sense — not to take you fully off-grid.
System size depends on your roof area, roof orientation and consumption profile. Most commercial systems Spirit Energy installs range from 50 kWp to over 1,000 kWp. A 50 kWp system needs roughly 250–300 square metres of usable roof space. Rather than oversizing for the sake of it, we size the system to match your demand — generating power you'll actually use on site delivers a far better return than exporting surplus.
There are three main routes. With capex you buy the system outright for maximum long-term return. With hire purchase you spread the cost over 3–10 years and own the system from day one. With a Power Purchase Agreement (PPA) a finance partner funds and owns the system, and you simply buy the electricity it generates at a rate below your grid tariff — no upfront cost. See our solar finance page for a full comparison.
Spirit Energy visits your site, assesses the roof, reviews 12 months of energy bills, and produces a site-specific financial model showing projected savings, payback period and IRR for your building and consumption profile. There is no cost and no obligation. From survey to written proposal typically takes 7–10 working days. To get started, request a quote online or call us directly on 0118 951 4490.
