2026-05-22 · SOLAR
String vs hybrid vs microinverters: decision tree updated
Updated for 2026 UK module options and the new G99 limits on microinverter installs.
The UK home energy stack reference. Solar, batteries, EV charging and heat pumps.
Reference guides on the kit and the install process. Calculators with the assumptions exposed. Decision-led articles for comparing quotes, tariffs and system designs.
Reviewed May 2026 · Tracks UK rules, tariffs and grants in 2026
Calculators
Payback, sizing and running cost calculators for UK homes
Built for the questions that crop up while reading a quote: solar payback against UK tariffs, battery sizing against your load shape, EV running cost on smart tariffs, and a heat-loss sanity-check.
Solar payback
Years to break even on the panels, given your roof and tariff.
Uses roof orientation, shading, tariff, behaviour
Battery sizing
Smallest battery that catches most of your spare solar.
Coming soon
EV running cost
Smart-tariff overnight charging vs standard rate.
Coming soon
Heat loss check
Sanity-check the survey figure your installer has quoted.
Coming soon
Latest updates
What changed this month
2026-05-18 · HEAT PUMPS
BUS grant rules refreshed for 2026-27
Eligibility detail for installs starting after 1 April 2026, plus the change to retrospective claims.
2026-05-12 · EV CHARGING
Octopus Intelligent Go tariff structure changes
New peak-window rate and revised export pricing for households with solar.
2026-05-05 · BATTERY
Battery payback on small solar arrays: scenarios rerun
New tariff inputs run through the model; numbers updated in the article.
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Articles
Recent articles
In-depth pieces on the bigger decisions, with the working underneath the conclusions.
Battery
·
14 min read
Are home batteries worth it on a small solar array?
When the payback maths works for storage on a sub-5 kWp solar setup, and when it doesn't.
Solar
·
9 min read
String vs microinverters for a split roof
How roof orientation, shading patterns and future plans drive the inverter choice.
Heat pumps
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17 min read
Why heat pump surveys disagree, and how to spot a bad one
What a good heat-loss survey looks like, and the red flags in a thin one.