Plug-In Solar vs Rooftop Solar: Which Is Right for You?
Last reviewed: 27 August 2026. Plug-in solar is legal in Great Britain from 27 August 2026 under SI 2026/848, for compliant devices. This page compares it with rooftop solar in the boring but useful way: cost, paperwork, output, and where each one makes sense.
£120–£500
Plug-in solar cost
£5,000–£10,000
Rooftop solar cost
800W
Plug-in max capacity
3–6kW
Rooftop typical capacity
The short version
| Feature | Plug-In Solar | Rooftop Solar |
|---|---|---|
| Max capacity | 800W (16A per phase) | Typically 3–6kW |
| Cost (incl. installation) | £120–£500 (DIY) | £5,000–£10,000 (installed) |
| Installation | DIY — plugs into 13A socket | Requires MCS-certified installer |
| DNO notification | G98 notification (within 28 days, no approval needed) | G99 application (pre-approval required) |
| MCS certification | Not required | Required (for SEG and warranties) |
| Building regulations | Not required | May apply (structural, electrical) |
| Connection | Standard 3-pin plug | Dedicated consumer unit breaker |
| Legal status (August 2026) | Legal from 27 August 2026 | Already legal |
| Portability | Yes — can take when you move | No — permanently installed |
| Suitable for renters | Yes (with landlord permission) | No (requires property ownership) |
| Annual generation | 300–900 kWh | 3,000–5,000 kWh |
| Annual savings | £70–£300 | £400–£1,000 |
| Payback period | ~2–3 years | ~7–12 years |
| SEG eligible | Yes | Yes |
What you actually plug in
Plug-in solar is a small photovoltaic system, up to 800W, made to connect to a normal UK 13A household socket. In practice you get one to four solar panels, plus a microinverter and a cable with a 3-pin plug. You fix the panels to a balcony railing or put them in the garden, plug the inverter into the wall, and the system feeds electricity back into your home wiring. It is legal in Great Britain from 27 August 2026, for devices that meet the official route.
I've put the longer version in the Complete Plug-In Solar Guide.
What rooftop solar involves
Rooftop solar is the familiar permanent solar PV system, typically 3–6kW, with panels fixed to roof rails and connected through a string inverter to a dedicated breaker in your consumer unit. It needs anMCS-certified installer, a G99 application to your DNO with pre-approval, and costs £5,000–£10,000 installed. It is already legal in the UK and has been for many years. It's proper building work, not a Saturday afternoon with a stepladder and misplaced confidence.
Which one fits your home?
Fast decision
- Choose plug-in solar if you rent, have a small budget, want a portable system, or want to test solar before committing.
- Choose rooftop solar if you own your home, want maximum generation and savings, and can afford the upfront cost.
Plug-in solar suits
- Renters or flat dwellers who cannot alter the building
- Homeowners who want to try solar before paying for a full system
- Balcony and garden setups, including flat roofs
- Budgets under £500
- People who move house often
- Adding a bit more generation beside an existing rooftop system
Rooftop solar suits
- Homeowners who want the highest generation and savings
- Properties with suitable pitched, south-facing roofs
- Budgets of £5,000+ and planning to stay 7+ years
- Adding battery storage for much less grid use
- Adding value to the property
- Cutting most or all of your electricity bill
What it costs
| Cost factor | Plug-In Solar | Rooftop Solar |
|---|---|---|
| Equipment | £120–£500 | £3,500–£7,000 |
| Installation | £0 (DIY) | £1,000–£3,000 |
| DNO notification | Free (G98 notification) | Free (G99 application) |
| MCS certification | Not required | Included by installer |
| Total upfront | £120–£500 | £5,000–£10,000 |
For the nuts and bolts of plug-in solar pricing, see the cost guide.
What it can save
| Metric | Plug-In Solar (800W) | Rooftop Solar (4kW) |
|---|---|---|
| Annual generation | 600–900 kWh | 3,500–4,500 kWh |
| Annual savings (self-consumption) | £70–£300 | £400–£800 |
| SEG income (export) | £10–£40/yr | £100–£300/yr |
| Total annual benefit | £80–£340 | £500–£1,100 |
| Payback period | ~2–3 years | ~7–12 years |
Both can be paid for export
Both plug-in and rooftop solar can be registered for the Smart Export Guarantee so you can be paid for electricity exported to the grid. SEG rates range from 1p to 12p/kWh depending on the supplier. It won't make you rich, but it does stop spare generation disappearing for nothing.
Can you run both?
Yes. If you already have rooftop solar, you can add a plug-in solar kit as a supplementary system, perhaps on a balcony or in the garden where the roof panels do nothing. You would still need to submit aG98 notification for the plug-in system within 28 days of installation. The total capacity for G98 notification purposes is per system, so each plug-in kit is a separate 800W system. It is not cumulative with the rooftop array.
Questions people ask
Can plug-in solar replace rooftop solar?
Yes, if your electricity use is modest and you want a low-cost way in. An 800W plug-in system will offset part of your daytime electricity use, but it won't cover your whole bill in the way a 4kW rooftop system could. Plenty of people will start with plug-in solar and move to rooftop later. That's a sensible route, provided you know the smaller system is not pretending to be a full roof array.
Can I fit rooftop solar myself?
Legally, you can, but you would need MCS certification to register forSEG payments, and most MCS schemes require professional installation. Rooftop solar also means working at height, checking the structure, dealing with electrics, and connecting to your consumer unit. I'd leave that to people who do it every week. Plug-in solar, by contrast, is designed for DIY.
Is plug-in solar big enough to matter?
An 800W plug-in system generates 600–900 kWh per year — enough to offset roughly 15–20% of an average UK household's electricity use. At 50% self-consumption, that saves about £148/year. The payback period is typically 2–3 years, which is quick by home energy standards. It won't run the oven for free all winter. It can still take a useful bite out of daytime use.
Start with the paperwork
Last reviewed on 18 August 2026. This is general guidance, not legal advice.