Plug-in solar vs rooftop solar in the North West: which pays back faster for you?

Since 27/08/2026, you can legally buy a plug-in solar kit, fix it to a balcony, wall or garden, and plug it into an outdoor socket yourself. That's good news for renters and flat owners who could never get panels before. It also raises a fair question for homeowners: is a £500 kit a better deal than a £7,000 roof system?

Here's an honest comparison using North West figures.

The short answer

A plug-in kit pays back much faster, but saves far less each year. Over 20 years, a rooftop system saves about four times as much on bills (around £9,300 against £2,300). Once you subtract what each costs, though, the net gain at today's prices is surprisingly similar, at roughly £1,800 each. Rooftop pulls clearly ahead if you get a premium export tariff, add a battery, EV or heat pump, or if electricity prices rise. A plug-in kit is the cheaper, lower-risk win.

These are indicative estimates. See "How we worked it out" below.

Who should choose plug-in solar

• Renters and flat owners. It's often the only realistic option. Under the Renters' Rights Act 2025, landlords can't unreasonably refuse a request to install one, but you still need written permission before fixing anything to walls or balconies.
• Homeowners who aren't ready to spend thousands. It's a low-risk way to start cutting your bill.
• People who are home during the day, or have always-on appliances. Plug-in kits only save money when you use the power as it's generated.

Who should choose rooftop solar

• Homeowners with a reasonably sunny roof who want the biggest long-term saving.
• Anyone planning a battery, EV or heat pump, which make far better use of rooftop solar.
• Anyone who wants export payments now, which plug-in kits can't yet get.

The rules for plug-in solar (from 27/08/2026)

• Up to 800W output, and one kit per home.
• Buy a complete, approved kit. It must be listed on the ENA G98 Type Test Register and carry a UKCA or CE mark. Don't mix cheap panels and inverters from online marketplaces.
• Plug it straight into an outdoor-rated 13A socket. No extension leads or adaptors.
• Tell your local electricity network operator within 28 days. This is a short online G98 notification, not an application.
• Mount it securely, away from walkways, fire escapes and windows.
• No batteries yet. Plug-in batteries aren't covered by the new rules.

How we worked it out

• Electricity price: 26.32p per kWh, the Ofgem price cap from 01/10/2026 to 31/12/2026.
• Sunlight: EU PVGIS data for the North West, assuming a south-east or south-west aspect. A south-facing kit or roof would generate more; east or west would generate less.
• Plug-in kit: 800W output, with 60% of the power used at home and no export income assumed.
• Rooftop: 4kW system with 40% of the power used at home, and the remainder exported at 4p per kWh (a typical standard export rate). Premium export tariffs of 15–25p shorten the payback.
• Costs: typical 2026 kit and installation prices, including 0% VAT on rooftop solar until 31/03/2027.

Your own figures will depend on your property, your roof or balcony direction, shading and how much electricity you use during the day.

Want your own numbers?

Tell us your postcode and roughly what you pay for energy, and we'll email you an independent estimate for both options within 24 hours. There's no phone number needed and no sales calls. If you want rooftop quotes later, you choose up to 3 vetted local installers, and only the ones you approve hear from you.