Savings & payback
Plug-in solar and smart meters: how they interact
A smart meter and a plug-in solar system meet at the same point: your home's electricity supply. Understanding how the meter sees solar makes it clearer why the savings come from using the power, not generating it.This guide explains the interaction and the unresolved export question. It builds on solar self-consumption.
Written and edited by Christopher Panteli
Christopher is the founder and editor of MyPlugInSolar. He oversees the site’s research standards, data tools and editorial process. He is not an electrician or solar installer, and specialist technical claims are sourced from official documentation or reviewed by appropriately qualified professionals.
What a smart meter measures
A smart meter records how much electricity flows in from the grid, and modern meters can also record electricity flowing back out. When your plug-in system is generating and you're using that power at the same time, it offsets what you'd otherwise draw from the grid — so the meter simply records less import. That reduction is exactly where the bill saving comes from, which is why self-consumption matters more than headline generation.
What happens to electricity you don't use
If the system generates more than the home is using at that moment, the surplus flows out to the grid as export. A smart meter can measure this, but measuring it and being paid for it are different things. Payment for export comes through schemes like the Smart Export Guarantee, and whether plug-in solar qualifies is unresolved — see can plug-in solar export to the grid?.
Use it, don't lose it
The open questions
Several things still depend on the rules being developed: whether plug-in solar can be notified and metered for export, whether export payments will apply, and how suppliers will treat it. These sit alongside the bigger point that plug-in solar is not yet legal to use in the UK (legal status). A smart meter doesn't change that — it just records what flows in and out.
Frequently asked questions
- Does a smart meter measure solar panels?
- A smart meter measures electricity flowing to and from the grid at your supply point. It doesn't meter the panels directly, but solar you use reduces your recorded import, and a smart meter can record any surplus you export.
- Do you need a smart meter for plug-in solar?
- Self-consumption savings happen regardless of meter type, because using solar simply reduces what you import. A smart meter matters mainly for measuring export — and whether plug-in solar export is paid for is still an open question.
Sources
- 1. Smart Export Guarantee (SEG) — Ofgem
Estimate your solar potential
See how much electricity a small system could generate at your postcode, and the indicative bill saving.