Are commercial solar panels right for my business?
A commercial solar panel array is a huge investment, no matter the size of your business. It’s important to understand exactly what you’re purchasing and how much electricity it will generate. Here are the essential things to understand when deciding whether commercial solar panels are right for your business.
How do commercial solar panels work?
A commercial solar panel system is designed to efficiently convert the solar energy from the sun into 230V, 50Hz electricity that normally comes from a plug in the UK. Here are the key steps:
- The sun shines on your solar panel array – The light from the sun contains solar energy. A commercial solar panel array is set up to maximise the light it receives from the sun throughout the day.
- The solar cells produce direct current electricity – The semiconductor materials within the solar panels produce a direct electrical current when light from the sun is shining upon the panel.
- An inverter converts the electricity to AC – All appliances in the UK are designed to work with alternating current electricity. An inverter system converts the electricity produced by the solar cells into AC.
- Use, store or sell the generated electricity – Your business can either directly use the generated electricity, store it for later use or sell it back to the grid through the smart export guarantee.
What is the lifespan of commercial solar panels?
Solar panels used at commercial properties are long-life assets that will reliably generate renewable energy for decades. A commercial solar setup has various components that need to be considered from a lifetime perspective.
The general consensus for solar panels is that modern panels will reliably generate electricity for 40+ years and degrade in efficiency by only half a per cent each year.
A typical manufacturer’s warranty will guarantee that a panel will still produce 85% of its original power output after 20 years. Given this strong promise, it’s safe to say manufacturers are confident panels will perform for much longer than this.
Other electrical components, like the inverter, will typically need replacing after 13 years. If you’ve chosen a system with solar batteries, these may need replacing every 10 to 15 years.
How can I estimate the number of panels needed for my business?
There are two key factors to consider when estimating the number of solar panels your business needs. These are:
- How much space do you have for solar panels?
- How much electricity do you want to produce?
Let’s first start with space. Businesses in the UK seeking to generate a lot of electricity will require a lot of space, and this is often a limiting factor. First, calculate the maximum number of solar panels your business could fit. See our section below for the dimensions of a typical solar panel.
Secondly, calculate how much electricity you want from your commercial solar panels. Here’s our handy article on calculating business energy usage.
The table below provides a rough guide to the amount of electricity you should expect to generate from a single solar panel in the UK. Divide the amount of electricity you would like to generate each month (in kWh) by the monthly electricity generation of each panel below to get the number of panels you will need.
| City | Average monthly peak sun hours | Monthly electricity generation from each 400W panel |
|---|
| Cardiff | 87 | 26.1 kWh |
| London | 84 | 25.2 kWh |
| Edinburgh | 72 | 21.1 kWh |
Source: Average peak sun hours – climate.biz, 0.75 factor applied to account for real-world conditions.
Note: The exact power generation from a solar panel is affected by factors such as the type of commercial solar panels you choose, the angle of your roof and the daily weather conditions.
How big are commercial solar panels?
Commercial solar panels are typically rectangular in shape and approximately two meters in length and one meter in width.
As a guide, the below table shows the dimensions of a range of panels currently available on the market.
| Cell type | Dimensions | Efficiency | Wattage | Weight | Cost (net) |
|---|
| Monocrystalline | 1.925 x 1.040m | 20% | 405W | 22kg | £88 |
| Monocrystalline | 1.722 x 1.134m | 21% | 410W | 21kg | £95 |
| Monocrystalline | 1.722 x 1.134m | 22% | 420W | 21kg | £110 |
| Monocrystalline | 2.278 x 1.134m | 21% | 550W | 27kg | £112 |
Source: Solar panel choices available solartradesales as of 1 September 2023