Plug-in solar
How Much Can Plug-In Solar Save in the UK? £70 to £110 a Year
An 800 W plug-in solar kit saves about £70 to £110 a year in Great Britain, by the government's figures. What drives the number, payback and how to save more.
Key facts
- The government estimates an 800 W plug-in kit saves about £110 a year tilted at 30 degrees facing south, and about £70 a year mounted vertically facing east or west.
- Those estimates assume 428 and 272 kWh a year used in the home, out of 690 and 378 kWh generated, for a household that is home all day.
- At the Ofgem price cap of 26.32p per kWh for October to December 2026, the same figures are worth about £113 and £72.
- Electricity you export without an export tariff earns nothing, so savings depend on using the power while the sun shines.
- At kit prices of roughly £340 to £600, payback ranges from about three to nine years.
An 800 W plug-in solar kit saves about £70 to £110 a year in Great Britain, according to the government’s July 2026 impact assessment. The top of the range needs panels tilted at about 30 degrees facing south, with someone at home during the day; panels hung flat on an east or west-facing balcony sit at the bottom. At kit prices of roughly £340 to £600, that is a payback of about three to nine years.
The government’s numbers
The Department for Energy Security and Net Zero (DESNZ) published two worked examples alongside the regulations that legalised plug-in solar. Both assume 800 W of panels, average UK sunshine, little or no shading, a household using the GB average of 3,323 kWh of electricity a year, someone home between 9am and 5pm on weekdays, and no battery. Savings count only electricity used in the home; exports earn nothing.
| Set-up | Generated per year | Share used at home | Used at home | Saving (July to Sept 2026 cap) | Same at 26.32p (Oct to Dec 2026) |
|---|---|---|---|---|---|
| 30° tilt, facing south | 690 kWh | 62% | 428 kWh | about £110 | about £113 |
| Vertical, facing east or west | 378 kWh | 72% | 272 kWh | about £70 | about £72 |
The vertical set-up produces barely more than half as much, yet loses less than half the saving, because a larger share of a small output is used in the home. That is the pattern of plug-in solar in one table: the kit can only save what your home is drawing at the moment the sun shines.
The government’s announcement on 26 August 2026 rounded this to savings of up to £110 a year, and said an 800 W kit can meet up to about 20 percent of an average home’s electricity use.
How the saving works
Plug-in solar does not send money anywhere. It reduces the number of kilowatt-hours your meter records as imported. Each unit your home takes from the panels instead of the grid saves your unit rate; nothing else on the bill changes.
Under the Ofgem price cap for 1 October to 31 December 2026, the average direct debit unit rate is 26.32p per kWh, with a standing charge of 54.83p a day. The government has removed VAT from electricity bills from 1 October 2026 to 31 March 2027, so that rate is VAT-free. The cap for January to March 2027 is due to be announced in late November 2026. If your tariff charges more per unit, your saving rises in proportion; if you are on a time-of-use tariff with cheap nights, daytime units are usually dearer and each solar unit is worth more.
What moves your saving up or down
Orientation and tilt. The biggest lever. South at around 30 degrees produces the most at UK latitudes; vertical east or west produces roughly 45 percent less in the government’s model. A south-facing railing beats a north-facing one by a wide margin, and a stand in the garden or on a flat roof can be angled. See the best direction and angle for plug-in solar in the UK.
Shading. A tree, a neighbouring block or the balcony above can halve output for part of the day. The government’s examples assume no shading.
Being at home. The examples assume a home-all-day household. If the flat is empty from 8am to 6pm, the base load of a fridge, freezer, router and standby devices still uses some output, but more of the midday surplus goes to the grid unpaid.
Where you live. Southern England gets noticeably more sun than northern Scotland. The government’s model uses average UK irradiance, so expect a little more in the south and less in the far north.
Season. Most of the year’s output arrives between April and September. A winter month produces a small fraction of a summer month; see plug-in solar in winter.
Panel size. The regulations cap the inverter at 800 W but allow up to 2,000 W of panels. Extra panel capacity raises output on dull days and in the morning and evening, though the inverter clips the peak. Our 400 W vs 800 W comparison looks at the trade-off.
Payback: what the kit costs against what it saves
As of October 2026, compliant kits listed by UK retailers ranged from about £340 for a single panel with an 800 W microinverter to around £1,000 for the largest kits, according to an independent price tracker; most two-panel kits sat between about £450 and £900. The government’s impact assessment expected many devices at £400 to £600. Retail purchases carry 20 percent VAT: the zero rate for energy-saving materials applies to installation services, not to goods bought without installation.
| Kit price | Saving £110 a year | Saving £90 a year | Saving £70 a year |
|---|---|---|---|
| £350 | 3.2 years | 3.9 years | 5.0 years |
| £450 | 4.1 years | 5.0 years | 6.4 years |
| £600 | 5.5 years | 6.7 years | 8.6 years |
| £800 | 7.3 years | 8.9 years | 11.4 years |
Simple payback, ignoring future price changes. If unit rates rise, payback shortens; if they fall, it lengthens. The government’s modelling assumes the microinverter needs replacing after ten years at about £100, a conservative assumption, while panels typically carry 25-year performance warranties. Over 20 years, a well-placed kit saving £110 a year returns roughly £2,200 in today’s prices for an outlay of about £500 to £600 including one inverter replacement.
An example for a typical flat
Take a two-person flat with a south-west-facing balcony, a railing-mounted 800 W kit costing £450, and one person working from home three days a week. That sits between the government’s two cases: say 450 kWh generated, of which 65 percent, or about 290 kWh, is used in the flat. At 26.32p that is about £76 a year and a payback of roughly six years. These are our illustrative assumptions, not measured figures.
Move the same kit to a stand on a south-facing garden patio at 30 degrees, and the government’s first case applies: about £113 a year and a payback of four years.
How to save more from the same kit
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Angle the panels if you can. A tilting bracket on a railing, or a ground stand, is worth more than any other change. Follow the manufacturer’s permitted mounting types and keep to the wind-load limits in the instructions.
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Move flexible loads into daylight. Run the dishwasher, washing machine and tumble dryer on a delay timer around midday on sunny days. A typical wash cycle uses roughly half to one kilowatt-hour.
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Charge in the day. Laptops, e-bikes, power tool batteries and phones charge just as well at noon as at night.
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Watch the app. Compliant microinverters must show status and output through a display or app. A week of watching tells you when your surplus appears.
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Keep the panels clean and unshaded. Trim what you are allowed to trim; clear leaves and bird droppings from the glass.
What plug-in solar will not save
It does not cut the standing charge. It does not pay for exports unless you have an export tariff; the Smart Export Guarantee guide explains why most plug-in users do not, for now. It does not store energy: kits with batteries are not allowed under the current rules, which is why plug-in solar with a battery is a separate question. And it does not work in a power cut, because the inverter switches off when the grid fails.
Next steps
Frequently asked questions
How much can plug-in solar save in the UK?
About £70 to £110 a year for an 800 W kit, according to the government's July 2026 impact assessment. The higher figure is for panels tilted at 30 degrees facing south, the lower for panels hung vertically facing east or west, both for a household that is home during the day.
How many kWh does an 800 W plug-in solar kit produce in the UK?
The government's model gives about 690 kWh a year for 800 W of panels tilted at 30 degrees facing south with little shading, and about 378 kWh mounted vertically facing east or west. Shading, a north-facing aspect or a location in northern Scotland reduce that.
How long does plug-in solar take to pay for itself in the UK?
Roughly three to nine years. A £400 kit saving £110 a year pays back in under four years; a £600 kit on a vertical, east-facing balcony saving £70 a year takes more than eight. The government's own modelling assumes the inverter needs replacing after ten years at about £100.
Can plug-in solar cut my standing charge?
No. The standing charge, 54.83p a day on average under the October to December 2026 price cap, is a fixed daily fee. Plug-in solar only reduces the number of units you buy from the grid.
Do I get paid for the electricity my plug-in solar exports?
Not automatically. Surplus power flows into the grid unpaid unless you have an export tariff. Smart Export Guarantee tariffs have eligibility criteria, and the government expects many plug-in users not to qualify at first.
Is plug-in solar worth it if I am out at work all day?
It still saves money, but less. Your fridge, freezer, router and devices on standby use some of the output all day, but much of the midday surplus will be exported unpaid. Running the washing machine or dishwasher on a timer during sunny hours recovers part of it.
Sources
- Plug-in solar final stage impact assessment (16 July 2026), Table 7
- Changes to energy price cap between 1 October and 31 December 2026
- Households can save as plug-in solar panels come to market (26 August 2026)
- Smart Export Guarantee (SEG)
- VAT on energy-saving materials and heating equipment (VAT Notice 708/6)
- 800W plug-in solar kits UK: verified kits and prices (checked 8 October 2026)
This guide is general information, not legal, tax or electrical advice. Your utility, state and local code have the final say.