One of the reasons we’re such massive advocates of solar PV is that the technology’s suitable for the vast majority of homes in the UK.
A perfect roof for solar PV would be large, south facing and pitched at an angle between 30º and 45º. But with the right panels and an expertly designed system, even a less-than-perfect roof can get brilliant results.
We’ve put this page together as a guide, but if you’re unsure about whether solar panels would be a good option for you the best thing to do is fill in our online form or give us a call. Below we’ve listed several points to consider.
Which way does your roof face?
The direction your home faces will determine how much sunlight it gets throughout the day. The closer this is to south the better, so panels mounted on a roof facing south, south west or south east will perform the best. But many people are surprised to learn that panels facing east or west only lose about 15% of the output they’d achieve if they faced due south.
What’s the angle of your roof?
The best angle for the panels to be positioned is between 30º and 45º. However, we can mount panels at any angle from 15º to 50º. Outside that range, the panels would start to lose performance.
Or, if you have a flat roof, we can mount a frame on top of the roof to raise the panels to the optimum angle. It brings a few extra considerations – like applying for planning permission and checking the roof can cope with the extra weight – but that’s what we’re here for.
Do you have space for the panels?
You’ll need a clear space of up to 24 square metres – about the size of a parking space. The area should be free from shading from trees, chimneys or other buildings for most of the day.
If you don’t have a lot of suitable roof space, one option could be to use fewer, but more efficient, panels. Again, this is something we can advise you about over the phone.
Is your roof structurally sound?
An individual panel isn’t heavy, but a whole solar array, plus the mounting frames that attach the panels to your roof, can weigh about 275kg for an average-sized system. It’s extremely rare that we come across a roof that’s unable to support this extra load, but this is one of the things we’ll check during our site survey.
How energy efficient is your home?
On 1 April 2012 the government made a change to its policy for feed-in tariffs (FITs), stating that only homes with an energy performance certificate (EPC) rating of D or above would be able to claim the full tariff.
The government estimated that around half of UK homes meet grade D already, but some properties – and older buildings in particular – may need a little extra help. Measures like energy-efficient boilers and cavity-wall and loft insulation all make a difference.
It’s important to note that a solar PV system counts as 1 point – enough to take you into the next band up. So if your house is currently only E rated, apply for your EPC after the system’s been installed and you should be a D.
EPCs were a part of the now-scrapped home information pack, so you may well have one already. If not, we can help. We’ll take you through the criteria over the phone to
estimate your home’s rating, and arrange for an accredited assessor to visit your home and provide the certificate.
Where do you live?
The further south you live, the more sunshine you’ll get. PV is definitely more popular in the south of the country, but you can still get good performance (and great returns) further north. We’ve installed all over the UK, and even been as far north as the Orkney Islands.
We follow the recommendation of the Building Research Establishment (BRE) and use the government’s Standard Assessment Procedure (SAP) to calculate each system’s energy output. One flaw with this system is that it doesn’t take location into account. So if you live in the south, it’s likely you’ll see better performance than predicted.
Do you have space inside your home?
The bulkiest piece of equipment is the inverter. It needs some clear space around it for cool air to circulate, so we recommend a space of about 1.5 metres high by 1 metre wide. A garage attached to your house is ideal, as the inverter will be accessible but out of the way. A spacious loft is also a good option.
You’ll also need space next to your existing meter or consumer unit for a fuse board, isolator and total generation meter. These will be mounted together on a piece of board of about 40 x 20cm.
How is your home connected to the grid?
Most homes have a single-phase connection. This will support a system of up to 4kWp, which is usually the maximum size for a domestic property. If you have plenty of space and want a bigger system we can guide you through the process, which involves seeking permission from your distribution network operator (DNO).