Home battery and plug-in solar guides
Plain answers with dated numbers and primary sources: tariffs, sizing, VAT, export, plug-in solar rules and getting your meter data.
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Are home batteries worth it in the UK?
When a UK home battery pays back: modelled savings for typical, EV and heat-pump homes, the 0% VAT deadline and a simple test for any quote.
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Best Octopus tariff for a home battery
Agile, Intelligent Octopus Go, Go, Flux or Cosy with a battery: verified time windows, who can join each one, and modelled savings by type of home.
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Home battery without solar: does it pay?
A battery with no solar panels charges from the grid and earns only on your own use. VAT, tariffs, export rules and G98 or G99, with modelled savings.
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What size home battery do you need?
5, 10 or 13.5 kWh? Modelled savings show a 10 kWh battery often saves no more than a smaller one. Size to your peak-hour use, not your yearly total.
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Battery VAT: 0% ends on 31 March 2027
Installed home batteries pay 0% VAT until 31 March 2027, then 5%, not 20%. What "installed by 31 March" means for deposits, invoices and DIY kits.
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Heat pump and battery: is Cosy enough?
Cosy Octopus windows, a heat pump's daily load shape and modelled battery savings in London and North Scotland, plus Boiler Upgrade Scheme grants.
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Plug-in solar UK: the rules from August 2026
Plug-in solar has been legal in Great Britain since 27 August 2026: 800 W, one per home, DNO registration. The rules, the exceptions and what a kit saves.
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Plug-in solar for renters: landlord permission
Renting or in a flat? Get written permission before buying plug-in solar. What to ask, the conditions landlords want, and the rules in England, Wales, Scotland.
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Export tariffs explained: SEG, Outgoing, Flux
How UK solar export tariffs work: the Smart Export Guarantee, Outgoing Octopus at 12p, Agile Outgoing, Flux export, and why batteries and plug-in solar differ.
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Download your smart meter data (half-hourly)
How to get a year of half-hourly smart meter data: Octopus API key or CSV, Bright/Glowmarkt, n3rgy or any supplier CSV, to test a battery or tariff.