Plug-in solar: kits, cost, and is it legal
For renters, leaseholders, and anyone who can't fit a full roof system — a plug-in or balcony kit generates real savings on a much smaller budget. Work through the steps below to size a kit, understand how it connects, and get a full plan.
Why plug-in solar?
A plug-in or balcony solar kit is a small (typically 400–800W) panel-and-microinverter system that plugs into a normal socket rather than being wired into your consumer unit by an MCS installer. Kits usually cost £300–1,200 and save £79–190 a year on a typical UK electricity bill, which pays back in roughly 3–8 years — nothing like the scale of a full rooftop system, but a fraction of the outlay and no roof access required. The trade-off is eligibility: plug-in kits don't qualify for Smart Export Guarantee (SEG) payments, because SEG requires MCS-certified installation, with one partial exception — Octopus Energy currently accepts some plug-in setups on certain tariffs. If you rent, have a leasehold agreement that rules out roof work, or just want to test whether solar is worth it before committing to a bigger project, this is where to start.
Plug-in vs full install vs DIY roof: what you actually get
The three routes to home solar sit at very different points on cost, effort, and return. A plug-in kit(400–800W) costs £300–1,200, saves £79–190 a year, pays back in 3–8 years, needs no roof access, and isn't SEG-eligible (bar the Octopus exception above). A full rooftop installation(4kWp, professionally fitted) costs £6,000–8,000, saves £450–660 a year, pays back in 8–12 years, and is SEG-eligible because it's MCS-certified. A DIY roof install sits in between on cost — see our DIY solar installation guide for the full breakdown — but still needs roof access and an electrician for the final connection. Plug-in solar has become the only one of the three you can legally self-install end to end: as of 27 August 2026, compliant kits can be self-fitted in Great Britain without an electrician, though you still need to notify your electricity network operator either way. If you're thinking about adding a battery to a plug-in kit, note that batteries sit outside this legal framework — the government's Interim Product Specification covers grid-tied generation only, not stationary storage, so a bundled battery may need separate consideration.
Own your home? Full solar could save you more
Plug-in solar is capped at 800W and can't earn Smart Export Guarantee (SEG) payments — it's built for renters and leaseholders who can't fit a full system. If you own your property, a full roof install earns SEG income (currently around 13p/kWh exported — supplier-dependent) on top of the electricity you use yourself (worth 26p/kWh at the current price cap), which plug-in solar can't access at all. A full install also currently qualifies for 0% VAT until 31 March 2027, saving roughly £1,100 on a typical 4kWp system.
| Plug-in solar | Full install | |
|---|---|---|
| Upfront cost | ~£300–1,200 | ~£6,100+ |
| SEG export income | Not available | Yes, with an MCS-certified install |
| System size cap | 800W | No cap — sized to your roof |
Plan your kit in 4 steps
- 5 min
Assess your space
Balcony, garden, or wall space and socket access — this determines what size kit makes sense.
Start step 1 - 10 min
Choose your kit
Plug-in solar is sold as a complete panel + inverter + cable system. Pick one, and add battery storage if you want it.
Start step 2 - 5 min
Is it legal, and who connects it?
Self-install is now legal for compliant kits — what qualifies, what still needs G98 notification, and what falls outside the rules.
Start step 3 - 5 min
Your plan
Your chosen kit, estimated savings, and how to get it sourced or connected.
Start step 4