The four main parts of a solar system
Every home solar installation is built from the same core components, regardless of which installer fits it. Understanding these four parts means you'll know exactly what you're paying for and what questions to ask when comparing quotes.
Solar panels
Rows of photovoltaic (PV) cells fitted to your roof that convert sunlight into electricity. Most UK homes use 10-16 panels, mounted on rails fixed to the roof structure. Panels generate direct current (DC) electricity.
Inverter
Usually mounted in a loft, garage or utility cupboard. Converts the DC electricity from your panels into alternating current (AC) — the type your household appliances actually use. If you have a battery, the inverter also manages power flow between panels, battery and home.
Battery (optional)
Stores surplus electricity generated during the day so you can use it in the evening instead of buying electricity back from the grid. Typically wall-mounted, about the size of a small suitcase. Most homes choose between 5kWh and 10kWh of storage.
Generation meter
Records exactly how much electricity your panels produce. This reading is what your energy supplier uses to pay you for electricity you export to the grid under the Smart Export Guarantee.
How the electricity actually flows
On a sunny day, electricity moves through your system in a simple sequence. Here's the path it takes from your roof to your plug sockets — or to the grid, if you're not using it all:
If you don't have a battery, any electricity you generate but don't use immediately is exported to the National Grid, and your energy supplier pays you for it via the Smart Export Guarantee (SEG). If you do have a battery, that surplus is stored first and used later — typically in the evening, when your panels aren't generating but your household demand is highest.
What happens during installation day
A typical domestic install takes one to two working days, depending on system size and roof complexity:
- Scaffolding or roof access is set up first thing, and panels and mounting rails are fitted to the roof.
- Cabling runs from the panels down into the property, usually through the loft, to where the inverter will sit.
- The inverter and consumer unit connection are fitted and wired in by a qualified electrician.
- Battery installation (if included) happens alongside the inverter — usually in a garage, utility room, or loft space.
- Testing and commissioning — the installer checks the system generates correctly and that all safety certifications are completed.
- Handover — you receive your MCS certificate, warranty documents, and a walkthrough of any monitoring app.
Before installation day, there's usually a 2-4 week lead time covering the initial site survey, structural roof checks, and notifying your local Distribution Network Operator (DNO) — a formality required for any grid-connected generation system.
Why MCS certification matters
MCS (Microgeneration Certification Scheme) is the UK's quality standard for installers of small-scale renewable technology, including solar PV. It exists to protect homeowners, and it matters for a few practical reasons:
- Smart Export Guarantee eligibility — you can only get paid for exported electricity if your installation was carried out by an MCS-certified installer using MCS-certified equipment.
- Mortgage and insurance compliance — many lenders and insurers require MCS certification for solar installations as a condition of cover or future remortgaging.
- Workmanship standards — MCS installers are independently audited against technical and consumer protection standards, reducing the risk of poor workmanship.
Every installer matched through Solar Near Me holds current MCS certification, so this is checked for you before you even receive a quote.
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Choosing a system size
System size is measured in kilowatts (kW) — the maximum output your panels can generate under ideal sunlight. It's matched to your roof space, household electricity usage, and budget. As a rough guide:
| System size | Typical panel count | Best suited to |
|---|---|---|
| 3.0 – 3.5kW | 8 – 10 panels | 1-2 bed flats and terraces |
| 4.0 – 4.5kW | 10 – 12 panels | 3 bed semi-detached homes |
| 5.0 – 5.5kW | 13 – 15 panels | 4 bed detached homes |
| 6.0kW+ | 16+ panels | Large detached homes, high usage households |
An MCS-certified installer will confirm the exact size your roof can accommodate and recommend a system based on a proper survey — these figures are a starting point for budgeting, not a substitute for that survey.