Solar Panel Glossary: Terms Explained for Manchester

kW and kWp: The size of a solar system: its peak output in kilowatts under standard test conditions. A system of ten 400-watt panels is 4 kW (often written 4 kWp). Read more
kWh: A unit of energy: what you are billed for. A kW of panels on the best central Manchester roof makes about 888 kWh a year. Read more
PVGIS: The European Commission's free online solar model, which estimates generation from satellite measurements of sunlight at any location. The figures on this site come from it. Read more
Pitch: The angle of a roof slope from the horizontal. Most pitched roofs on Manchester houses sit between 30° and 45°.
Azimuth or orientation: The compass direction a roof slope faces. South is best in the UK; east and west make about a fifth less in Manchester. Read more
Inverter: The box that turns the panels' direct current into the alternating current your home uses. It usually needs replacing once during the life of the panels.
Optimiser: A small device fitted behind a panel so that shade on one panel does not drag down the others. Useful on roofs shaded by chimney stacks. Read more
MCS: The Microgeneration Certification Scheme, which certifies installers and products. An MCS-certified installation is needed for export payments. Read more
RECC and HIES: Consumer codes that most solar installers belong to. They set rules on sales, deposits and complaints. Read more
Network operator (DNO): The company that owns the local cables. In Manchester it is SP Electricity North West, not your energy supplier. Read more
G98: The connection route for small generators, up to 16 amps per phase (3.68 kW single-phase): the installer connects and then notifies the network operator. Read more
G99: The route for larger systems, including many solar-plus-battery set-ups: the network operator must agree before connection. Read more
Export limitation: A setting or device that caps how much power a system can send to the grid at once, sometimes used to stay within connection limits.
Smart Export Guarantee (SEG): The rule that larger energy suppliers must pay something for electricity you export. Each supplier sets its own rate. Read more
Self-consumption: The share of your panels' output you use in the home as it is made, rather than export.
Permitted development: Building work that does not need a planning application because it meets national limits. Most roof solar on houses qualifies. Read more
Conservation area: An area the council protects for its character. Manchester has 35; they add limits on walls and balconies that face a highway. Read more
Listed building: A building on the national heritage list. Solar on a listed building needs listed building consent. Read more
Outrigger: The narrower back extension on many terraced houses, with its own small roof. Read more
Leasehold and freeholder: How most flats are owned: the leaseholder owns the flat, the freeholder keeps the roof and structure. 28.1% of Manchester households live in purpose-built flats. Read more
Plug-in solar: Small panel kits that plug into a socket, legal in Great Britain since 27 August 2026 when they meet the standards. Read more
EPC: Energy Performance Certificate: a rating of a home from A to G. The Warm Homes: Local Grant needs an owner-occupied home to be D to G. Read more
Warm Homes: Local Grant: The grant for lower-income households in England, run in Greater Manchester by GMCA. It can include solar and batteries for eligible homes. Read more
GMCA: The Greater Manchester Combined Authority, which runs some services, including the Warm Homes: Local Grant, across the ten boroughs.
Retrofit assessment: A survey of a home that recommends improvements in order. Grant-funded work follows it.

Solar glossary: the terms in plain English

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