A 100kW system is one of our most requested sizes, built for manufacturers, farms and larger retail sites looking to make a serious cut to their energy bills. Start with a free assessment of your roof and your bills.
100kW suits manufacturers, farms and larger warehouse or retail roofsA 100kW system at a glance
184 x 545W panels for a 100kWp DC array (100,000W / 545W, rounded up).
At 5.45m² per kWp of array installed: 100kWp x 5.45m².
At 850kWh per kWp installed a year: 100kWp x 850kWh.
Profit comes down to income and expenses. Energy-intensive industries, such as manufacturing, have long faced high running costs, with significant investment going into lowering the energy consumption of individual machines.
A 100kW system could be a strong fit for your business. Get your free assessment and we will confirm the right system size for your roof and your usage.
A 100kW system has a maximum rated output of 100kW, needing around 184 panels at 545W each for a 100kWp DC array, and covering around 545 square metres. A typical system includes:
| Period | Maximum output (kWh) |
|---|---|
| Hourly | 100 |
| Daily | 600 |
| Weekly | 4,200 |
| Monthly | 18,000 |
| Yearly (theoretical max) | 219,000 |
Theoretical maximum under ideal, cloudless conditions. Real-world UK output, at 850kWh/kWp, is around 85,000kWh a year.
Our own 100kW package example (below) uses a slightly larger 110.09kWp DC array of 202 panels on the same 100kW inverter, which is why its own figures run a little higher than the 100kWp nominal numbers on this page.
Connected to the grid, powering your lights, equipment and machinery by day, and exporting any surplus under the Smart Export Guarantee.
Generates and stores energy in a battery, so surplus power can be used later in the day rather than exported straight away.
Operates independently of the grid, reserved for remote sites where a grid connection is too costly, unavailable or unreliable.
The food and beverage industry alone makes up 14% of UK industrial electricity bills; a 100kW system can meaningfully cut that cost.
A medium dairy farm can use 200,000-300,000kWh a year; a 100kW system generating around 85,000kWh a year offsets a real share of that.
Large or wholesale retail can use 500,000-1,000,000kWh a year; a 100kW system typically offsets a meaningful share of daytime demand.
A 100kW system typically costs from around £90,000, made up of panels, inverters, mounting and electrical equipment, and professional installation.
Business premises pay the standard 20% VAT rate on a commercial installation - the residential 0% VAT relief does not apply. You can, however, set the full cost against your taxable profit using the Annual Investment Allowance, since it sits well within the £1m AIA cap. At the 25% main rate of corporation tax, that is worth around £22,500 off your corporation tax bill on a £90,000 system.
Higher-efficiency panels cost more upfront but generate more over their lifetime; a certified installer and a strong warranty matter more to your lifetime return than the initial price alone.
We provide bespoke system designs for every business, based upon your energy usage and rooftop availability. To give you an idea of the savings and cost of a system, below are some of our common system sizes.
For office buildings
25 yearsPays back in 6.2 yrs
For warehouse buildings
25 yearsPays back in 6.0 yrs
For manufacturing plants
25 yearsPays back in 5.8 yrs
For distribution centres
25 yearsPays back in 5.7 yrs
Illustrative examples, not live quotations. Equipment, warranties and prices are confirmed in your proposal. All savings are based upon a solar generation yield of 850kWh/kWp installed per annum, with usage of 71.43% of solar energy generated, assuming a 24p/kWh electricity import rate (close to the DESNZ Q1 2026 UK non-domestic average of 24.14p/kWh). Savings may change year on year dependent upon weather conditions, energy prices and system degradation in line with warrantied output.
Solar PV brands featured in our system examples
Figures above assume a 24p/kWh electricity rate, close to the Q1 2026 average.
The right route depends on your cash position, your lease and how much power you use in daylight. Your free assessment models each one against your own bills, starting with what you can save before a single panel goes up.
Review your electricity tariff whilst planning your solar installation
Best for: Any business on an out-of-contract or uncompetitive tariff
Ask about this route
Pay upfront, keep every pound of the saving
Best for: Profitable businesses with cash or an existing facility, and a long lease or freehold
Ask about this route
Spread the cost, with ownership at the end of the agreement
Best for: Businesses that want ownership without tying up working capital
Ask about this route
Fully funded. You just buy cheaper electricity
Best for: Sites with a large roof and daytime demand that want savings with no capital or maintenance
Ask about this routeFinance and fully funded options are subject to eligibility, survey and contract terms. Savings, repayments and tax relief depend on your circumstances.
When it comes to commercial solar, there are a few ways to purchase your system. We’ll help to guide you through your options.
Using the Annual Investment Allowance, you can deduct the cost of your system against corporation tax.
Spread the cost with asset financing and use your bill savings to pay off your annual loan repayments.
Purchase your system outright, for the best return on investment.
Or pay nothing upfront with a solar power purchase agreement. See all four ways to pay.
Get a forecast based on your building, tariff and daytime electricity use.
We will check if you qualify for any incentives or grants.
Your assessment uses your postcode to check local solar yield, planning rules and the grid connection.
Prefer to talk first? Call 0113 834 0644 or email [email protected].
Your installation is managed by Solar4BusinessInstallation services described below are delivered by our partner Solar4Business.
Our expert in-house team will advise you on how to best save money through a bespoke business solar installation.
A few questions about your business and your solar energy needs.
A 100kW (or similar) package sized to your roof and your usage, with every way to pay modelled.
Solar4Business surveys your roof and installs your system, and we check any grants or incentives available to you.
You start saving on energy bills from the day your system is switched on.
See the range of buildings featured in Solar4Business’s published installation projects, from manufacturing sites to schools.
Commercial solar at industrial scale. A large manufacturing roof put to work generating electricity on site.
Explore the project
Rooftop generation alongside the demands of a busy manufacturing operation.
Explore the project
Using school roof space to generate power where it is needed throughout the day.
Explore the project
A bespoke rooftop installation designed around a business headquarters.
Explore the projectBusiness Solar UK helps you assess your options and introduces you to Solar4Business. Their team surveys your premises, designs the system and manages the installation.
Solar4Business displays the accreditation marks below on its website. Ask for the current certificates, the contracting company’s details and the warranties that apply to your proposed installation.
Founder and CEO, Pharaoh Capital. Founder of Solar4Business and INICIO.
Over ten years in the energy sector. Grant founded Solar4Business, who install every Business Solar UK system, and INICIO, which funds commercial solar with no upfront cost. Institute of Directors Young Director of the Year, 2020.
Getting a 100kW system through Business Solar UK is straightforward. We:
If this page has shown you the benefits a 100kW system could bring, get your free, no-obligation solar assessment and we will confirm what it would look like for your roof and your bills.
Get your free solar assessmentReviews are of Solar4Business, who carry out every installation for Business Solar UK. Rating as at 22 September 2026.
"All went well with the initial enquiry, report draft and install. We were kept up to date with install dates and the guys on site were tidy and professional... There has been a marked reduction in our electricity costs which was the reason for the install."
"Steve and his team were extremely professional, installing over 900 panels for our Academy."
"We have a commercial property and 48 solar panels have been fitted. The team of installers were extremely professional and helpful."
"A great installation. Steve and the team did a great job. Would not hesitate to recommend this company."
Brands using solar power
Around 184 x 545W panels for a 100kWp DC array, covering around 545m² of roof or land. Your free assessment measures your actual usable space before any system is designed.
Yes. Business premises pay the standard 20% VAT rate on a commercial solar installation. The 0% VAT relief only applies to residential installations, and runs until 31 March 2027.
The Annual Investment Allowance lets you set the full cost against taxable profit in the year of purchase, up to £1m a year - solar is special-rate plant, so any spend above the AIA can then claim a 50% first-year allowance.
Systems up to 50kW usually qualify for MCS certification; above that, larger or export-heavy systems need approval from your local distribution network operator before connection. Solar4Business handles this application as part of the design.
On suitable sites, yes, through a solar PPA. Our funding partner INICIO pays for the system, which Solar4Business installs. Its maintenance is covered under the agreement, and you buy the electricity it generates at an agreed rate per kWh.
Save massively on your electricity bills when you invest in solar.
