Choosing A Solar Energy Installer

Warning: With energy prices rapidly increasing, there has been a huge demand for solar installations. Many installers are really busy and have a busy order book. Even getting an installer to quote can be a challenge at the moment. Do NOT rush into making a commitment though, unless you are confident in your chosen installer. Making a rash decision could cost you a lot of money and result in a lot of anxiety.

This page on selecting an installer is part of my article on

Whilst researching and progressing my smart home solar energy project, I spent a lot of time trying to find the right installation company. My elderly father had a very bad experience with a solar installer, so I my expectations of the industry in general were pretty low. I had to put this bias aside though and try to find a company I could trust and work with.

This page simply aims to provides guidance on selecting a solar energy installer, the things you need to consider, the things you need to ask and documentation required. I cannot claim that is a complete list, as I am always learning new things in the solar energy space.

Note: This guide is specific to the UK only.

I am offering free, independent advice on this page. I have no affiliation or interests with any company or organisation in the solar energy space. My motivation is purely to help educate people to make better decisions when it comes to purchasing, installing and using solar energy technology. Knowledge gives you power. I link to third-party websites as examples only and these should not be considered endorsements or recommendations. I also link to research published by my own smart home consultancy company by way of example only.

MCS Certified?

The first thing you need to do is check that an installer is Microgeneration Certification Scheme (MCS) certified on the mcscertified.com website. If they claim to use an MCS certified sub-contractor then be very wary. An MCS certificate is only valid if you have a contract with an MCS certified organisation.

From what I learnt during my research, Microgeneration Certification Scheme (MCS) certification is not really going to help you to resolve any issues but, it does serve three useful purposes:

An MCS certified installer should have a certain level of training and is following a well documented, standardised installation approach.
You need an MCS installation certificate on completion of your installation, in order to be able to apply for Smart Export Guarantee (SEG) payments. Your energy provider will need to see this.
The installation won't be covered by an HIES insurance backed warranty if it is not MCS certified. This may or may not be important to you.

Online Reviews

Warning: Do NOT trust online review sites such as Trustpilot and TrustATrader. Their reviews are often polarised, tainted with fake reviews and a company can simply 'flag' and hide reviews they don't like. My father had a very poor experience with a company that features on both these websites and despite presenting plenty of facts and evidence, both have removed or hidden my honest review.

Personal Recommendations

Personal recommendations are by far the best way to help choose a solar installer. I had several close friends that had used my chosen installer and although they had a few minor concerns, the quality of the work done was very high. It is not always possible to get personal recommendations though.

Social Media Groups & Forums

You can learn a huge amount by just listening to discussions within things like Facebook groups and their are several relevant to the UK solar industry:

Solar & battery UK (including any other renewable energy source/storage) (Facebook group)
Solar Energy UK (Facebook group)

Note: Many UK solar installers are members of these groups, so unhappy customers are often reluctant to discuss their experience within a group like this. Your best bet is to ask an open question about a specific installer and to invite private messages from people about their experiences.

Cold Callers

Avoid any company that cold calls you! This is true of pretty much any industry, not just solar energy. These companies will be sales driven, with a sales-person calling you, with sales targets. They are likely to be pushy and use pressure techniques, such as 'limited time offers'. There may be a few that are also committed to good service but, it is unlikely that you are speaking to them. Why take the risk?

Online Adverts

Be very wary of any online adverts and "deals". These are just another sales generation tactic.

Surveys

There are some companies that will ask to do a remote survey, most will want to visit. I'd be really wary about a company that won't come and visit the premises, to do a proper inspection. They are going to miss things and have to estimate measurements. They really need to look at the roof structure to be sure it can support the extra weight of the solar panels and it has no structural issues hidden behind the tiles.

These are the questions I asked of the companies when doing installation surveys:

Is the installer MCS certified?
How and where will the various bits of equipment be installed?

Solar Panels

Are you happy with the appearance of the panels? They do vary quite a lot in appearance and colour.
How many solar panels can be fitted on your roof? Ask to see the proposed installation layout. Good installers will use a design tool to plan out and provide accurate estimates.
What is the specification and performance of the panels?
Do the solar panels work independently?
If a solar panel fails, will I know?
How long is the warranty on the panels?
Are panels fitted with bird mesh protection? If so, how is this being fitted? Screwing bird mesh to the panels will invalidate the warranty.
Will any of your panels be in shade? If so, are optimisers or micro-inverters being fitted?

Inverter(s)

What type of inverter(s) are being installed?
What is the specification and performance of the inverters?
Will the inverters handle the full solar panel(s) output?
What power will the inverter be able to deliver to my home?
What power will the inverter be able to deliver to the network?
What power will the inverter be able to deliver to the battery?
What approval & certification does the inverter have?

Network

Will the installer apply for G98/G99 approval on your behalf?
Can you see how much power is being sent to the grid in real time?

House

Can you see whole home power usage in real time?

Battery Storage

What type of battery and capacity of battery storage will be installed?
What interface is exposed to my contextual smart home?
Is this interface wired or wireless?
Can you control when the batteries are used over mains power?
Can you access battery state information?
Can you control when the batteries are charged?
Can you access solar PV power generation information in real-time?
Can you access grid usage information in real-time?
Can you access battery usage information in real-time?
What is the warranty on the battery?
Is it possible to upgrade the battery storage at a later date?

Electric Car

What interface is exposed by the electric car charger?
Can you control when the car is charged?
Can you access electric car battery charge state information?

Quotations

It is really important that your quotation lists exactly what you are getting as it forms the basis of the contract between you and your installer. If there are things missing, get them added. If there are things that don't look right, get them changed. If you have any doubts about something, ask the question in writing and ensure you get a written response. Good installers will have no problem with doing this.

An Microgeneration Certification Scheme (MCS) certified installer will provide a quotation that includes some estimates of the energy the proposed installation will generate, how much of it will be used and how much will be exported. This should also include projections on how long it will take to recoup the costs of the equipment installed.

A quotation should include the following (assuming they are part of the proposed installation):

The number of solar panels being installed, the brand & power output.
The number of optimisers or microinverters being installed, the brand and model. The specification will confirm that they are suitable for the solar panels.
Bird mesh protection, if required.
The inverter make, model and power output.
Any inverter extras such as networking components, extended warranty, etc.
The battery make, model and usable storage capacity. This should ideally include the maximum charging rate and maximum discharge rate.
Application to the DNO and delivery of the DNO approval. Make sure you know if this is a G98 or G99 request. Typically, you should sign a 'letter of authority' for the installer to do this on your behalf but, sometimes this is implied in the contract.
Delivery of the MCS certificate for your installation.
Any charges for scaffolding (if required).
A clear view of how much (if any) VAT you are paying on each item.

In addition, you need to have in writing:

The warranty period of all items should be listed.
The payment schedule required (i.e. 20% deposit + full payment on completed installation). If some items are coming later due to stock issues, it needs to be very clear what is paid when.
When the DNO response and Microgeneration Certification Scheme (MCS) certificate will be handed over. It is quite normal for this to be done after the final payment. I've heard of many examples where less scrupulous installers withhold the paperwork.

Payments

You installer should outline the expected payment schedule in their quotation. It is normal to pay a deposit up front of around 10% to 20% of the total cost. The balance would then be due, once the installation has been completed and the equipment has been commissioned and tested. You should expect a demonstration and guidance on how it works, including monitoring apps, etc.

Warning: If you have concerns over the quality of the equipment, missing equipment, equipment not matching the quotation or equipment is missing, then it is best to withhold some or all of the balance due until your concerns are addressed. The amount withheld needs to be proportionate though.

For you own protection is is advisable to pay some or all of the amount due using a credit card. So long as this is more than £100, you are then provided additional protection by your credit card company.

It is normal for the 'handover pack' to be delivered after the final payment has been made.

Handover

On completion of the installation and commissioning, you should receive a 'handover pack'. The most important documents in this pack are:

DNO approval document
MCS certificate

In addition to these documents, you should also be supplied with:

A copy of the invoice, marked 'paid in full'.
Insurance backed warranty details
The maintenance requirements and maintenance services available
A certificate signed by the Installer containing the following as a minimum:

A statement confirming that the solar PV system meets the MCS requirements:
Client name and address.
Site address (if different).
Installer name, address etc.
List of key components installed.
Estimation of system performance.

Operation & maintenance manual should include system data with basic system information, a single line electrical schematic.
A copy of the manuals and data sheets for the system components.
A copy of the test and commissioning documentation.
Operation and maintenance data.

Note: Some of these documents may be provided before final payment is made, especially if part of the installation is subject to equipment supply issues and delays.

Other

If scaffolding is being installed, this will probably be subcontracted out. The biggest challenge facing the scaffolding industry is storage of the poles, planks, etc. This means they may come and install scaffolding very early, just to have it safely stored somewhere. They may also leave it up long after the installation is complete. Make sure any scaffolding installed does not restrict access to garages, gates, etc.

If you found this page useful you can buy me a coffee. This helps me maintain this website and add more content.