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The honest guide toSolar & battery.
Solar PV, batteries, and the maths behind self-consumption, including the seasonal generation question.
Solar & battery
Who this is for
For homeowners weighing up solar panels, with or without a battery, who want the sums for a British roof rather than a brochure's.
The questions these guides answer
- How much does a solar system cost to install, and how long does it take to pay back?
- How much does it generate in winter, when you need it most?
- Is a battery worth adding, and what changes the answer?
Worth knowing first
On EU JRC modelling, a 4 kWp south-facing system in London generates about 4,100 kWh a year, and December to February produce only about 13% of that. Without a battery a typical home uses about 15% to 29% of its own solar power, rising to roughly 48% to 62% with 5 to 6 kWh of storage. Panels and batteries carry 0% VAT until 31 March 2027.
Reading order: beginner first
Start at the top.
06 guides
- 01
What is solar PV?
Solar PV panels turn daylight into electricity, and an inverter makes it usable in your home. A 4 kWp south-facing system in London generates about 4,100 kWh a year, and the Energy Saving Trust puts a typical 4.5 kWp system at around £7,600 installed. A battery is optional.
6 min read
- 02
Do solar panels work in winter?
Yes. Solar panels run on daylight, not warmth, so they keep generating in winter, just less. A 4 kWp south-facing system in London makes about 144 kWh in December against 493 kWh in June, and December to February produce only about 13% of the year's output.
7 min read
- 03
Solar without a battery vs solar with a battery: what changes
Without a battery, a typical home uses about 15% to 29% of its own solar power; with 5 to 6 kWh of storage that rises to roughly 48% to 62%. On solar alone a battery rarely pays for itself, but a time-of-use tariff, a heat pump or an EV can change the sums.
8 min read
- 04
How much do solar panels cost in 2026?
What solar panels cost to install on a UK home in 2026, with and without a battery, how much a London roof generates month by month, what export tariffs pay, and an honest payback calculation you can check.
9 min read
- 05
How much does a home battery cost in 2026?
What a home battery costs with or without solar panels, how much it can save on a time-of-use tariff, how long it lasts, and when the numbers do not add up.
8 min read
- 06
How much does it cost to install an EV charger at home?
What a home EV charger costs to install, what pushes the price up, the grants still available for flats and renters, and how to charge for less.
7 min read
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