Best Solar Companies: How to Check One Before You Sign

The single most valuable habit when choosing a solar company is simple: verify, do not trust. Every badge on a website can be checked against an official register in under two minutes, and the companies worth hiring will happily point you to them — the ones that hesitate are telling you something. Sola UK holds MCS, RECC and TrustMark accreditation, and we would encourage you to confirm each one on the relevant register rather than take our word for it.

Once a company clears those four checks, the decision comes down to the eight questions below. Good installers answer all of them without hesitation — hesitation is data:

A logo on a website is a picture of a claim, not the claim itself. Each row below is a register you can search yourself, free, by company name. The middle column matters most: these schemes prove different things, and people routinely read one as if it proved another.

We have deliberately not published a ranked table of named firms with review scores. Scores move, counts move, and a figure copied into a guide is out of date by the time you read it — so the honest version is to tell you what each type of company commits you to, and to send you to the live listing for the rest.

Local independent installers are companies with their own employed installation teams who operate within a defined geographic area. The key advantages of local independents include deep knowledge of local planning requirements, direct accountability for the quality of work, and accessible aftercare. When something goes wrong, you are dealing with the same people who installed your system. The main consideration is that smaller companies may have longer lead times during busy periods.

National chains and large solar companies benefit from significant buying power, which can translate into competitive pricing on equipment. However, many national companies use subcontracted installation teams who may have limited local knowledge and varying quality standards. If issues arise, you may find yourself dealing with a call centre rather than the people who actually installed your panels. The disconnect between the sales team and installation team can also lead to miscommunication about what was promised versus what is delivered.

Aggregators and lead generators are platforms that collect your details and pass them to multiple installers for quotes. While this can save time in gathering quotes, you have no control over which companies contact you, and the installers are paying a referral fee that is typically built into your quote price. The quality of installers in these networks varies widely and you should independently verify any company you are referred to.

London's complex urban landscape makes local knowledge invaluable for solar installation. From navigating conservation areas in Camden to understanding parking suspension processes in Haringey, an installer who works in your area every day will deliver a smoother, more efficient project. They know which scaffolding companies are reliable, which boroughs have specific requirements, and how to manage installations in tight terraced streets.

Scaffolding logistics alone can make or break a London installation. A local installer understands the lead times for scaffolding permits, the costs of parking suspensions in different boroughs, and how to plan efficient installations that minimise the time scaffolding is on your property. National companies unfamiliar with London often underestimate these factors, leading to delays and unexpected costs.

Aftercare is perhaps the most important reason to choose local. If your inverter develops a fault or a panel is damaged in a storm, you want an installer who can respond quickly rather than one based hundreds of miles away. Local companies build their reputation within the community and have a strong incentive to maintain excellent service standards.

Sola UK operates primarily across North London and Hertfordshire, giving us detailed knowledge of this area's specific solar requirements. From the Victorian terraces of Finchley to the conservation areas of Hampstead, and from the modern developments of Enfield to the period properties of St Albans, our team installs solar systems across the full range of property types found in this region.

North London and Hertfordshire represent an ideal area for solar energy, combining relatively high sunshine hours with affluent property owners who value both the environmental and financial benefits of solar power. The region's mix of property types — from compact terraces to sprawling detached homes — means we have experience designing systems for virtually every roof configuration.

London is the most expensive region in Great Britain for small systems: the DESNZ Solar PV cost data for 2025/26 gives a London mean of £2,101 per kW up to 4 kW, against £1,808 for Great Britain. That makes like-for-like comparison more important here, not less. Line the quotes up on the same panel brand, inverter type, battery capacity, warranty terms and scaffolding inclusion; a lower headline price may reflect different components or a shorter warranty.

Check each quote's MCS performance estimate, which is calculated for your roof's orientation and shading, rather than comparing headline system sizes. Two 4 kW quotes on different slopes are not the same product.

Most domestic solar in London is permitted development, but the rules changed on 27 August 2026 and a lot of published advice has not caught up. The amended Part 14, Class A of the General Permitted Development Order is the document that matters, and three points in it are routinely misreported.

First, the conservation-area restriction is narrower than usually stated. Paragraph A.1(2)(e) withholds permitted development where the land is in a conservation area or a World Heritage Site and the equipment would go on a wall, a balcony or a roof enclosure that fronts a highway. A roof slope is not caught by that wording, so a rear-slope array on a conservation-area house is frequently still permitted development — which is the opposite of what “no panels in conservation areas” implies.

Second, listed buildings moved. Under A.1(2)(g) a listed dwellinghouse is now outside Class A altogether, as is a listed block of flats under A.1(1)(e). That means planning permission as well as listed building consent, where previously the permitted development route could apply and only consent was needed. If your home is listed, treat solar as a planning application from the outset.

Third, there is a transitional window, and it is narrower than “pick whichever rules you prefer”. Article 6(2) of the amending Order lets a developer carry out previously permitted development until the end of 26 August 2027 — it preserves a permission that existed before 27 August 2026 and that the amendments removed. It does nothing for a scheme that never qualified under the old wording.

Wall-mounted equipment also has a new allowance: under A.1(2)(a) it may project up to 0.4 metres beyond the plane of the wall, dropping to 0.2 metres where the wall abuts a highway, with the same limits applying to balcony and roof enclosures under A.1(2)(b).