How does commercial solar work?
The short answer: panels on your roof or land turn daylight into electricity, inverters make it usable, and your business uses that power first. Anything left over goes to the grid for an export payment, and the grid tops you up whenever solar is not enough.
How it works, step by step
1. Panels generate DC power
Solar cells in each panel turn daylight into direct current electricity.
2. Inverters convert it to AC
Inverters change DC into the alternating current your building uses, and monitor the system.
3. Your site uses it first
Power flows into your distribution board and is used by lighting, machinery, chillers and IT before any grid power.
4. Surplus is exported or stored
Unused power goes to the grid for an export payment, or into a battery for later.
5. The grid fills any gap
When solar is not enough, grid supply tops up automatically. You never run short.
Where the savings come from
Every unit you generate and use on site is a unit you do not buy from your supplier, so the biggest savings go to businesses that use power during the day. Exported units earn less, which is why systems are sized around your daytime demand. Read how solar cuts business energy bills and the Smart Export Guarantee guide.
The main parts of a system
- Panels: see panel size, efficiency and output.
- Inverters: see our inverter guide.
- Mounting: roof, ground or carport frames.
- Monitoring: see solar monitoring.
- Optional battery: see battery storage.
What it costs and how to start
Costs and payback are covered in our cost guide and ROI and payback guide. If you are wondering whether it suits you, start with are commercial solar panels worth it and what installation involves.
Want to see how it would work on your building?
The calculator gives an indicative saving in minutes. A free feasibility review then checks your roof, electricity use and funding options.
Frequently asked questions
What is commercial solar PV?
Commercial solar PV (photovoltaic) is a solar panel system installed on a business, public or industrial building, or its land, to generate electricity for that organisation's own use.
How do commercial solar panels work?
Panels turn daylight into direct current (DC) electricity. Inverters convert it to alternating current (AC), which feeds into your building's electrical system and is used first by whatever is running on site.
What happens to electricity I do not use?
Surplus electricity flows to the grid. With an export tariff such as the Smart Export Guarantee, you are paid for those units, though usually less than you pay to buy electricity.
Does commercial solar work on cloudy days?
Yes, but output is lower. Panels generate from daylight, not direct sun, so they still produce on overcast days. Your grid supply automatically makes up any shortfall.
Does commercial solar work at night?
Not without storage. At night you use grid electricity, or power stored earlier in a battery if you have one.
Do I still need a grid connection?
Yes. Almost all commercial systems stay connected to the grid, which supplies power when solar is not enough and takes any surplus you export.
Read next
Related guides & sector pages
Are commercial solar panels worth it?
The 2026 UK business case - payback, IRR and risk.
Read GuideBenefits of commercial solar panels
Why UK businesses invest in rooftop solar.
Read GuideBest commercial solar panels 2026
Top panel brands compared for UK commercial roofs.
Read SectorFactories & manufacturing
Match daytime process loads with on-site solar.
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Explore related pages
- Commercial solar panelsSystems, costs and benefits for UK businesses.
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- Commercial solar installersHow we design, install and support your system.
- Solar potential by postcodeSee local solar yield for your business postcode.
- Savings calculatorIndicative size, cost and payback in a minute.
- Sectors we work withWarehouses, factories, cold storage and more.