Find the right solar panel installer for your home
If you’ve decided to take the plunge and get solar panels for your home, you need to find an installer.
However, not all installers were created equal. There are good, bad, and ugly ones. Our job is to help you find a good one!
The first steps to take are:
- Get three quotes
- Read through their proposals carefully
- Ask as many questions as you need to
The guide below will help you weed out the installers that are not up to the mark. It will also help you get even more out of the very best solar panel installers.
The Hard Sell
Some companies try to sell solar panels like double-glazing.
They sit in your living room and won’t go away until you have signed on the dotted line. This is a huge red flag. Don’t sign!
The reason they pressurise you into signing is that they are over-charging by thousands of pounds. They know that if you don’t sign now, you won’t sign later. As soon as you get three quotes in, their over-inflated price will stick out like a sore thumb.
If the person visiting you is highly sales-oriented, beware. On the other hand, if they feel more like a surveyor and actually spend a lot of time measuring and checking, you’re probably on to a good thing.
A High Price
Once you have your three proposals in writing, compare the total prices including VAT.
Imagine the prices are as follows:
- 1st Poposal: £7,500
- 2nd Proposal: £7,900
- 3rd Proposal: £13,000
Assuming the equipment is broadly comparable across the proposals, then the 3rd proposal is clearly far too expensive.
Don’t be fooled into thinking the higher price means better quality. It almost certainly won’t.
That extra money – £6,000 or so – will go towards one or more of the following:
- A hefty commission for the sales person
- Over-inflated profits for the installation company
- Paying for mass marketing or call centres
Not on Checkatrade or equivalent
Checkatrade is a website helping consumers find local tradesmen.
You can also read feedback on Checkatrade about each company. This feedback is left by previous customers of the company in question.
Other places to look for feedback and reviews online are Trustpilot and Google Reviews.
Can you trust online feedback? The answer is, generally, yes you can. Just be aware that if the feedback sounds artificial, it probably is.
Having said that, it’s a big red flag if the solar panel company has no public-facing review pages at all.
Ask yourself: why doesn’t the company want genuine feedback? If you have high standards, getting excellent feedback from your customers is something you want to shout about from the rooftops.
No References
Before signing the contract to go ahead, you should ask the installer to provide you with three references.
You should then speak to these previous customers and ask them how they got on with their solar panel installation.
Check, for example, if there was good service after the solar panels were put in. Did the company help get that broken tile fixed? Was the right paperwork sent through?
If an installer seems reluctant to send through references, or keeps ‘forgetting’, that is not a good sign.
Scaffolding
Most solar installations go on a pitched roof about 5m from the ground.
This is the height of the gutter of a 2-storey house. To keep the roofers safe, there should be a fully-boarded scaffold platform along the gutter where the panels are going.
Scaffolding is expensive. It’s a ‘dead cost’ to both you and the installer. It has to be put up and paid for, but doesn’t form part of your solar panel array.
For this reason, some installers try to avoid it altogether. With no scaffolding, your quote will be lower. In fact, it will be several hundred pounds lower. This might clinch the sale for the company.
Be careful. Think: what does this mean about the company?
Scaffolding is a safety issue. It keeps the roofers safe when working at a height. If the solar company is asking their own roofers to work off ladders – instead of a solid scaffold – they are taking liberties with their safety.
If the company is willing to risk the safety of their own people in this way, to save money, imagine what other corners they will cut to make more money out of you.
In summary: ask the company if they use scaffolding and how they ensure the safety of the roofing team.
Exaggerated Forecasts of Generation, Savings, Payback Period, etc.
Each of your three proposals will come with various forecasts.
For example:
- Estimate of annual solar generation in kWh
- Savings on your electricity bill
- Payback period
- Savings from water immersion controllers, etc.
Sometimes this data is very well laid out and explained. Sometimes it is not. This can be a very confusing area for consumers.
To cut through the fog, ensure that all three proposals, and their forecasts, are based on the same assumptions. For example, these figures should be the same in all the quotes:
- How much you currently pay per kWh for your electricity. Use the ‘day rate’. This is around 24.67p per kWh at the moment under the Ofgem Energy Price Cap (April–June 2026). You can find the exact figure on your electricity bill.
- What your typical annual consumption of electricity is. For homes, this is generally between 2,000 kWh and 12,000 kWh. Your bill may give you a figure for this, or you can extrapolate from one month’s data.
- The Energy Price Inflation rate. This is the rate by which your energy company increases the cost of your electricity in kWh each year. Generally the range is 5% to 10%. Again, ask all three companies to set it to the same rate.
- The ‘self-consumption’ percentage for the solar electricity. This is how much of the solar electricity you actually use in the home. This is normally set to a maximum of 50%. If it’s above 50%, it may be the installer is trying to exaggerate the likely returns. Ask why it has been set above 50%. It might be higher than 50% if you are also having battery storage or a water immersion controller.
If all three proposals are based on the same criteria above, then it will be much harder for any of the installation companies to pull the wool over your eyes.
Poor or Impossible Panel Layout
All the proposals you receive should include a visualisation of how the panels will look on your roof.
If one of the proposals doesn’t include a panel layout, ask for it.
A good system designer will take the surveyor’s measurements and come up with a sensible design. You will be able to recognise your roof and see where the panels are going.
Sometimes solar panel companies are so incompetent that the panel layout they propose is impossible. The panels simply won’t fit on.
For example, they might propose 10 panels in portrait and your roof measures 9m in width. As a solar panel is roughly 1m wide, 10 panels together will measure roughly 10m. If your house is only 9m wide, the row of panels clearly won’t fit on.
Look at all the panel layouts you receive and compare them. In theory, all the designs should be similar. If one proposal fits on far more panels than the other two, it’s probably a sign that they have miscalculated.
You may also encounter ‘lazy’ designs. The company just throws a few panels up there without much thought. A clever designer could have got more panels on to increase your overall system size.
Always ask the person trying to sell the system why the layout has been done in that way.
No Product Descriptions or Data-sheets
Proposals should contain descriptions and data-sheets for the main components of a solar panel system, namely: the solar panels themselves and the inverter.
You should be able to see clearly the manufacturer and model number for both the panels and the inverter.
If a proposal doesn’t contain this data, it’s a bad sign.
The solar company may simply install the very cheapest equipment they can find in the week that your installation goes ahead.
If you do go ahead with an installer, it’s also a good idea to look at the data labels on the equipment when it arrives at your house.
Make sure the data label on the back of a solar panel matches the make and model in your proposal. The same for the inverter.
The Wrong Mounting Fittings
Your solar panels aren’t attached directly to your roof for standard ‘on roof’ installations.
First an aluminium frame is attached to your roof and then the panels are mounted on the frame.
The aluminium frame itself is attached to ‘roof hooks’ or ‘roof anchors’ which are screwed into your rafters (see our page that describes exactly how a solar panel system is installed).
Which roof hooks you choose depends on the type of roof covering you have: concrete tile, slate, clay, etc.
Bad installers will often use the cheapest roof hooks they can find. They won’t necessarily be right for your roof.
Make sure you ask your installer to prove that the roof hooks they propose are right for your roof.
For ‘in roof’ installations – where the panels are flusher to the roof and replace your tiles – the panels are laid in large plastic ‘trays’, rather than being mounted onto an aluminium frame. As long as the installers follow the in-roof manufacturer’s instructions carefully, all should be fine.
Second-hand Equipment
By default, all the equipment for your solar panel system should be brand new.
The inverter should be in a new, sealed box. Solar panels are usually delivered on a pallet direct from the wholesaler or come in the installer’s van.
Ask your preferred installer if all the equipment is new. When the equipment arrives on installation day, have a look at it.
If something doesn’t look right, query it with the installation team.
No PV*SOL Design
Most good solar panel companies will include a PV*SOL design in the proposal.
PV*SOL is German software that designers use to recreate your house in 3D and then place solar panels on.
It takes into account your exact location on the earth, local weather patterns, the orientation of your roof, its exact pitch, any shading elements such as trees or chimneys, and so on.
PV*SOL makes very accurate predictions as to how many units (kWh) of solar electricity will be generated each year.
Getting this kWh figure right is very important for your returns and payback period.
If the proposal contains a full PV*SOL report that’s a great sign. If it doesn’t, it might be an indicator of a lazy company.
Please note: PV*SOL is not the only solar design software. If one of the proposals contains a report from another competent piece of software, that’s fine.
No Information about Planning Permission
Generally you don’t need planning permission to install solar panels.
However, if your house is listed or within the boundary of a listed building, you do.
The better proposals will quote UK planning law concerning residential solar panel systems. You can then make your own mind up whether you need planning permission or not.
The less competent proposals tend not to even mention planning at all.
Trying to Sell you Lots of Extras
Another sign that the installer is more interested in their own profits than in your well-being is if they try to sell you loads of extras.
A solar panel quotation should normally be for just solar panels and the inverter. That’s it. Of course there will be extra items like cabling, mounting kit, etc., but the main items are solar panels and inverter.
The main, genuine, low-cost extra the installation company might suggest is an immersion controller. These divert excess solar electricity to heat your water. These can be a good idea, though you shouldn’t pay more than about £500-800 inc. VAT, supplied and installed.
In addition, battery storage might be proposed. Please read our Battery Storage page for further details.
The extras which you may not need include:
- Voltage optimisers
- Heating controls
Many of the brochures for these devices make dubious claims. We’re not saying they are all bad, but you should definitely do your homework.
