Our recommendation is to maximise the size of the system based on the roof area you have available and the budget at your disposal. You earn income from your supplier for anything you don’t use, so this approach makes sense financially. A typical UK home uses around 3,500kWh of electricity per year if it uses gas (or other fuels) for heating. To generate the equivalent amount over the course of a year – you’d need around 4kWh of PV, or 10 solar panels. If you use electricity for heat as well and want to generate the equivalent amount, then it will be substantially more.
Strictly speaking, there is no average number of solar panels required. What is required depends on your budget, the space you have available, and what you’re trying to achieve. Do you want to maximise the return on your investment? Do you just want to use one roof elevation? Do you want the most panels for your given budget? Are you planning other changes like switching to a heat pump? All of this affects what is required in terms of the number of panels.
As a guide, the table below provides a breakdown of the typical sized systems you find on homes of different sizes. Bear in mind your property may be different and the opportunity you have to install panels may not correspond to what you see in the table.
Yes! If you have some nice clear sunny roof spaces to use, the easiest way to look at this question is first to look at your energy bill. Find out how much electricity you use - let’s say it’s about 3,600kWh (it’ll be about this figure if you use gas, oil or LPG to heat your home - and you don’t live in a mansion!). Divide that number by 900. This will give you the system size in kW. In this case we now have a 4kW system. Multiply that number again by 2.5 and you have the approximate number of panels you’ll need to generate the same amount of electricity you use. So, in this case, we would need 10 panels.
Remember, solar panels generate more in the summer than in the winter. Whilst this system will generate around 3,600kWh per year, there’ll be a lot more than you need in summer (which you export and earn money from), and a lot less than you need in the depths of winter: you will then buy electricity in from the Grid.
It certainly does. The further south you are in the UK, the more sunlight there typically is, and therefore the output of the panels will be higher. In the north of the UK, you’re down to about 750kWh per kW of solar array. Compare this to the very south of the UK, where it’s up at over 1,000. To generate the same amount of energy, someone in Durham will need more panels than someone in Dungeness, it’s just the way it is! Where you live therefore makes a difference, but all locations in the UK will see a return on their investment in solar technology.
The orientation of your panels will also have an impact – south is best, but anywhere south of east and west (and even panels on east and west elevations) is fine. We never recommend panels on elevations that face any northerly direction. Unless you have built your home in the southern hemisphere, in which case go for it.
The number of solar panels you need depends on what space you have available, how much electricity you use, and your budget. There is no firm answer to this question and it is therefore all about you.
Remember – by using Thermly you’ll also be contributing to your local community – every time an installation goes through the platform we put £50 into a pot that will be distributed as grants to local charities and third sector organisations. It’s a win-win for everyone.
We’re looking forward to helping you on this journey to a cleaner, greener, cheaper energy future.
Speak to one of our team: get in touch via our contact form https://www.thermly.co.uk/contact or call us on 0800 029 3129
Our short Heat Pump Readiness Assessment is free, and only takes a few minutes. Sometimes a bit longer with a cup of tea...
