Energy Utilisation
Outgoing Octopus Export Tariffs: Fixed, Agile & Flux (UK)
Outgoing Octopus pays you to export solar. I compare the Fixed, Agile and Flux rates, who each one suits, and why export income is only half your real ROI.
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
Can You Legally Install Solar Panels Yourself in the UK?
- 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
Push Your Installer for a Bigger Battery and More Panels
- 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.
Fundamentals
Solar Panel Angle Calculator UK: Best Tilt, Direction & ROI
- 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.
Fundamentals
Overpaneling in the UK: DC/AC Ratio, Benefits, and Limits (2026)
- 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.
Fundamentals
Are Solar Panels Worth It in 2026? Payback by System Size
- 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.
Fundamentals
Solar Panel Essentials: From Sunlight to Power Production
- 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.
Fundamentals
What Is a Solar Inverter? How They Work, Types & Cost (UK)
- 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.
Fundamentals
Batteries for Solar Panels: Types, Sizing and Costs (UK 2026)
- 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.