Solar Energy Concepts

DIY Solar for UK Homes. Real guides from a real install.

Step-by-step practical guides, component lessons, and hard-earned fixes from a real UK DIY solar setup.

7.15kWpinstalled 6,072kWhgenerated 2025 £1,668/yrmodelled value

Latest field notes

Practical and DIY

DIY solar is legal in the UK, but the connection to your consumer unit is notifiable electrical work: a registered electrician certifies it, or Building Control inspects it.
Going DIY costs you MCS, which means no SEG export payments from most suppliers (Octopus Outgoing aside) and 20% VAT on parts instead of 0%.
You can still do plenty yourself: the panels, the racking, the DC side and your own G98 or G99 notification. This is my read of the rules, not legal advice.

Energy Utilisation

Installers size for annual average. Typical UK household sits at 7.4 kWh/day, pointing the formula at an 8 to 10 kWh battery.
Winter usage is +27% higher and solar drops to 29.6% of summer yield. Average sizing leaves a gap.
Extra capacity at install earns £59 to 72/year per kWh on a time-of-use tariff, with 4 to 6 year marginal payback.
Retrofit costs 30 to 50% more than the same kWh added at install.

Updated 17 Jun 2026 Read Entry →

Fundamentals

Use the calculator below to compare tilt, direction and 10-year ROI for your roof. It covers every UK region; the optimal angle barely changes across a postcode area.
The textbook optimum is 35-40° facing south, but east-west and even vertical setups beat it for many real households.
Flat roofs win summer, steep walls win winter. Match the angle to when you actually use power.

Updated 17 Jun 2026 Read Entry →

Fundamentals

Overpaneling increases UK annual yield, especially in winter and low-light conditions.
The key metric is DC/AC ratio — oversize within inverter and DNO limits.
Done correctly, it improves ROI without automatically requiring a bigger inverter.

Updated 15 Jun 2026 Read Entry →

Fundamentals

A 4kW system at £7,000 pays back in 12-13 years at January 2026 prices, then delivers roughly a decade of near-free electricity.
Self-consumption decides the result: using your own solar saves 27.69p/kWh, exporting it earns as little as 5p.
A battery lifts self-consumption to 70-80% and usually beats panel-only setups on total returns.

Updated 15 Jun 2026 Read Entry →

Fundamentals

Solar panels convert sunlight to DC electricity via photovoltaic cells. An inverter converts this to usable AC.
UK-standard panels: 430–490W, N-type TOPCon or HPBC cells, 22–24.5% efficiency.
Direction matters: south-facing produces ~978 kWh/kWp/year. East/west produces ~81% of that.
Panels last 25+ years with minimal degradation. The inverter and battery are replaced first.

Updated 15 Jun 2026 Read Entry →

Fundamentals

The inverter is the control centre that converts PV output into usable household power.
Hybrid vs string vs microinverter is a design decision, not just a brand choice.
Choosing correctly up front avoids expensive rework when adding batteries or expanding later.

Updated 14 Jun 2026 Read Entry →

Fundamentals

Most UK homes need a 5-10kWh LFP battery to store surplus solar generation and avoid selling it back to the grid at 4-15p/kWh only to buy it back at 24-35p.
LFP (lithium iron phosphate) is the standard choice in 2026: 6,000+ cycles, no thermal-runaway risk, and around £124-176/kWh at the right sizes.
Size your battery to cover your full daily consumption, not just evenings. A 3-bed home using 2,900 kWh/year needs roughly 5.3kWh usable capacity plus 20% headroom.
DC-coupled batteries with a hybrid inverter are cheaper for new systems; AC-coupled makes sense when retrofitting storage to an existing solar setup.

Updated 14 Jun 2026 Read Entry →

Fundamentals

Hybrid inverters are the safest default for most UK homes because they keep battery, solar, and tariff optimisation options open.
String inverters are simplest and cheapest when the roof is clean, unshaded, and unlikely to need battery storage later.
Microinverters earn their keep on awkward roofs with shading, mixed orientations, small extensions, or panel-level monitoring needs.
Check DNO limits, MPPT voltage/current, battery compatibility, and export controls before buying, because the wrong inverter is expensive to unwind.

Updated 14 Jun 2026 Read Entry →