Wigan Solar Glossary: The Words on a Quote

MCS: Microgeneration Certification Scheme: the certification body for small-scale renewable installers and products. MCS asks buyers to check that the installer is certified and uses certified products. More on this
MCS certificate: The document the installer registers for a finished system. Export tariffs need it, and a future buyer of the house will ask for it. More on this
Consumer code: A set of rules for selling to households, approved by the Chartered Trading Standards Institute; RECC and HIES are two such codes. More on this
RECC: The Renewable Energy Consumer Code. Its members follow rules on contracts, deposits, warranties, complaints and how performance estimates are calculated. More on this
HIES: Home Insulation and Energy Systems, another consumer code covering renewable installers. More on this
Green Homes Dispute Resolution: The independent dispute service RECC members give their customers access to, at no cost to the customer. More on this
Performance estimate: The installer's written forecast of what the system will make in a year, in kWh. Compare it with the PVGIS figure for your roof direction. More on this
kW, kWp and kWh: kW (or kWp, "peak") is the size of a system; kWh counts the electricity it makes. Each kW facing south in central Wigan gives about 927 kWh a year. More on this
Price per kW: The total price divided by the system size, the fairest way to compare quotes. The North West mean for systems up to 4 kW was £2,021 in 2025/26. More on this
Inverter: The box that turns the panels' direct current into the alternating current the house uses; usually the first part to need replacing. More on this
Optimiser: A small unit behind each panel that stops one shaded panel pulling down the others; worth asking about on a roof with a chimney or dormer. More on this
Scaffolding: Usually a separate line on a quote; ask whether it is included and who arranges it. More on this
Commissioning: Testing and switching on the finished system. MCS asks buyers to check that the price covers it. More on this
Electricity North West: The company that runs the local electricity network in the Wigan borough and the rest of the North West. More on this
G98: The connection route for small systems with inverters up to 16 A per phase (3.68 kW single-phase): the installer notifies the network after commissioning. More on this
G99: The route for larger systems, or solar with a battery over the G98 limit: the installer applies, and the network must agree before connection. More on this
Cancellation period: Fourteen days to cancel most contracts made at home or at a distance, under the Consumer Contracts Regulations 2013. More on this
Deposit protection: Cover that returns a deposit if the firm stops trading before the work is done; ask how yours is protected. More on this
Good Trader Scheme: A list of traders that Wigan Council's Trading Standards page links to and describes as reliable and reputable. More on this
Conservation area: A district the council protects for its character; the Wigan borough has 23. Roof panels within the limits stay permitted; walls and balconies facing a road do not. More on this
Permitted development: Work that needs no planning application because national rules already allow it within set limits; panels on a house roof usually qualify. More on this
Warm Homes: Local Grant: The government-funded grant GMCA runs as its "GM Wide Scheme", for lower-income households, with postcode, benefit and income (under £36,000) routes. More on this
Zero-rated VAT: Installed solar panels and batteries in homes carry 0% VAT until 31 March 2027; a quote should show the VAT line. More on this
Plug-in solar: Small kits that connect through an ordinary socket, allowed up to 800 W under the 2026 regulations. More on this

Wigan solar glossary: the words on a quote

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