How to check a solar installer in St Helens

The registers

1. MCS. Search by postcode (WA9, WA10, WA11 and nearby) and choose solar PV. MCS certification is what your export tariff, the Warm Homes schemes and most lenders will ask for.
2. A consumer code. Firms selling to households must belong to one approved by the Chartered Trading Standards Institute; for solar that is usually RECC or HIES. The code sets rules on contracts and deposits and gives you a free dispute route. Check its own member list.
3. Companies House. The company's age, its directors and whether its accounts are filed on time.

TrustMark registration is a further check worth making, and needed for some funded work.

The survey and the shade assessment

In a town of terraces and shared chimney stacks, the shade assessment is the part of the survey most worth watching. MCS's installation standard works out the predicted yearly output as the system size times a regional yield factor times a shade factor. Where there is shade, the installer must tell you the factor was worked out by the MCS method and give you the sun-path diagram it used. Look at it: are the stacks, the houses opposite and the trees you know about on it?

Also expect the surveyor to look at the roof covering and its condition, the rafters or trusses, the consumer unit and earthing, and where the inverter and any battery would go, and to ask how you use electricity through the day.

A quote you can compare

• Panels, inverter and any optimisers by make and model.
• System size and predicted yearly output, with the shade factor stated.
• Scaffolding, roof work, electrical work, network notification and certificates, priced or stated as included.
• Warranties on panels, inverter and workmanship, and who insures the workmanship warranty.
• The deposit, how it is protected, and when the other payments fall due.

Compare the price per kW with the North West figures, and the predicted output with PVGIS for your roof less what the shade checker suggests.

Warning signs

• A price that only holds if you sign today.
• "From the council" or "the government scheme" with no application behind it.
• No shade assessment on a roof with stacks or neighbouring buildings to the south.
• A predicted output well above PVGIS for your direction and pitch, with no explanation.
• A large payment up front before any work.

Questions only a St Helens address raises

• Which network operator? Towards Newton-le-Willows and Haydock, ask the firm to confirm the operator for your street before it notifies anyone.
• An Article 4 area? In parts of Rainford, Rainhill, Vulcan Village and High Street, Newton-le-Willows, the council's guide lists solar on front elevations among works needing permission.
• Whose stack? A shared chimney stack on the party wall belongs partly to the neighbour; panels must stay clear of it, and its shade belongs in the assessment.

After you sign

A contract agreed in your home, or anywhere away from the firm's premises, can normally be cancelled within 14 days without a reason. If you ask for work to start sooner and then cancel, the firm can charge for what it has done. Citizens Advice sets out the rules.

Related pages

• Prices
• Shade checker
• Network connection
• Solar jargon

References

1. MCS installer search
2. RECC, the Renewable Energy Consumer Code
3. HIES (Home Insulation and Energy Systems) consumer code
4. TrustMark: quality scheme for tradespeople
5. MCS MIS 3002 version 6.0: the solar PV installation standard
6. MCS MGD 005: solar PV shade evaluation procedure (shade factor)
7. Citizens Advice: changing your mind about a service