How plug-in solar works

Plug-in solar — sometimes called “plug-and-play” or balcony solar — is a small solar system that connects to your home through a standard socket rather than being wired into the roof. This page explains, in plain terms, what the parts are and how the electricity they generate is used by your home.

One essential caveat first: in the UK, plug-in solar cannot currently be legally sold, supplied or used. A Government consultation that could change this is open until 30 June 2026. We cover the detail on the the UK legal status page.

The parts of a plug-in solar system

A plug-in kit is deliberately simple. It is made up of a few components that work together to turn sunlight into electricity your home can use.

The panels (DC)

The panels are the part that faces the sun. When daylight hits them they produce direct current (DC) — a steady, one-direction flow of electricity. The brighter and more direct the light, the more they produce. DC on its own is not what your home's sockets and appliances use, so it needs to be converted.

The microinverter (DC to AC)

The microinverter is the key piece. It converts the panels' DC into alternating current (AC) — the form of electricity your mains supply uses. Crucially, it produces AC at the same voltage and frequency as the grid and synchronises with it, so the electricity it makes can blend seamlessly with your home's supply. With plug-in systems the inverter is small and built into, or attached to, the panel itself, which is why the kit can be so compact.

The connection lead and socket

A connection lead carries the AC from the microinverter to your home. With plug-in solar this is designed to connect through a standard socket or a dedicated connection point, rather than being hard-wired into the property. That simplicity is the whole appeal — and also why the rules around it are being looked at so carefully.

How it works, in three stages

From a homeowner's point of view, the whole process comes down to three steps.

• 1. Place the panels. The panels go somewhere they catch good daylight — a balcony rail, a garden frame, a wall or a flat surface. The more direct sun they get across the day, the more they generate.
• 2. Connect via the microinverter. The microinverter converts the panels' DC into mains-compatible AC and synchronises it with your supply. The connection lead then links the system to your home.
• 3. Use the electricity. The electricity flows into your home's circuits and is used by whatever is switched on at that moment, before you draw anything from the grid.

How the electricity is used: self-consumption first

When the system is generating, that electricity is used by your home first. If your fridge, router or other appliances are drawing power at that moment, they take it from the solar before pulling anything from the grid. This is called self-consumption, and it is where the value comes from: every unit you use as it is generated is a unit you do not have to buy.

Because generation happens during daylight, plug-in solar is best at covering steady daytime background use rather than evening peaks. The more of your usage that overlaps with sunny hours, the more of the output you actually benefit from.

What export means

If the system generates more than your home is using at that moment, the surplus does not vanish — it flows back out to the network. This is called export. Export is normal for any solar system, but with plug-in solar the surplus may not earn you anything, depending on how any future rules and supplier arrangements treat it. In practice, the savings come from self-consumption, not from export.

Monitoring

Most systems come with monitoring, usually through an app, so you can see how much you are generating in real time and over days, weeks and months. This is genuinely useful: it helps you understand when you generate most, nudges you to run flexible loads — a dishwasher or washing machine — during sunny hours, and lets you see how close your usage is to your generation.

Why output is limited compared with rooftop solar

A plug-in system is small — typically one or two panels — whereas a rooftop array is many panels covering a much larger area. Output is roughly proportional to the panel area and how well it faces the sun, so a small system simply collects far less energy over a day. Plug-in panels are also often mounted vertically or in less-than-ideal spots (a balcony rail or wall) rather than at the optimal roof angle, which reduces output further.

As a rough guide, a well-placed 800W system might generate around 600–900 kWh a year in the UK, though the real figure depends on size, location, orientation and shading. Our calculator uses PVGIS data to estimate output for your specific postcode.