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

Council solar group buying is real and low-hassle: hundreds of households register together, installers compete in a reverse auction, and you get a vetted, fixed-price, MCS-certified install without chasing quotes yourself.
The MCS certificate is the real win, not just the discount: it’s what lets you sign up to a Smart Export Guarantee tariff and get paid for surplus power. A true DIY self-install without MCS can’t access SEG at all.
Budget six to nine months, not weeks: register, auction, personalised offer, a separate acceptance deadline, technical survey, then install. Real homeowner timelines on MoneySavingExpert show this spread.
You’ll pay roughly 20 to 40% off retail list prices, but that’s off full retail, not off a quote you’ve haggled down, so get one independent quote to benchmark.
The full UK list by region, plus the blank spots: Scotland, Northern Ireland and the North East have no scheme at all, so look at grants and loans instead.
Push for more panels and a bigger battery up front, and ask for a G99 connection if you’re sizing up. Retrofitting a battery later is fiddly, so get the spec right before you accept.

Updated 27 Jun 2026 Read Entry →

Fundamentals

Heat reduces output: modern panels lose roughly 0.26-0.30% of power for every °C above 25°C cell temperature.
A hot UK day costs about 8-10%: at 28°C ambient and strong sun, cell temperature can hit ~56°C, not a wipeout.
Summer still wins by a mile: PVGIS shows July yielding roughly three times January’s output in London, driven by daylight, not temperature.
Cold and bright is the sweet spot: below 25°C cells can briefly exceed nameplate rating; my own best output came on a cold, clear May morning.
Mounting matters: rack-mounted panels with an air gap run cooler than flush in-roof systems, clawing back a few percent.
The inverter feels the heat too: most units derate above 40-45°C ambient, so siting it cool and ventilated matters.

Updated 26 Jun 2026 Read Entry →

Practical and DIY

CRC errors on Solar Assistant usually mean the RS485 cable is too long, poorly terminated, or picking up interference.
Fix: shorten cable, add 120Ω termination resistor, use shielded twisted pair cable.
Affects Sunsynk and Deye inverters connected via Modbus RS485 to Solar Assistant.

Updated 22 Jun 2026 Read Entry →

My Components

Best DIY inverter in the UK — hybrid, 3.6kW AC, dual MPPT, battery-ready, G98 compliant. Around £750.
Owner since May 2023 — running two strings + 16.1kWh Fogstar battery + Solar Assistant automation.
Generator port trick: my system has processed 6.3kW of solar power at once by combining both PV strings with an extra inverter on the generator port.
Drawbacks: app data refreshes every 5 min (use Solar Assistant instead), CT clamp inaccurate beyond 15m, SOC reporting quirks with parallel batteries.

Updated 22 Jun 2026 Read Entry →

Practical and DIY

G98 covers up to 3.68kW. Beyond that, you need a G99 application to your DNO.
G99 is an application, not a notification — expect 30–60 days for approval depending on your DNO region.
You need a single-line diagram (SLD) showing your full system layout. Templates and examples included.
DIY systems can apply for G99 — you do not need an MCS installer for the application itself.

Updated 22 Jun 2026 Read Entry →

Fundamentals

Optimisers are most useful on imperfect roofs with shading, mismatch, or complex layouts.
On clean unshaded arrays, gains may be small relative to added hardware cost.
Use measured yield impact and system complexity to decide if they are worth it.

Updated 22 Jun 2026 Read Entry →

Practical and DIY

A solar gazebo doubles as a garden structure and a generation asset — useful if roof space is limited or orientation is poor.
DIY build cost: timber frame + panels + microinverter from around £1,500.
Orientation flexibility: a freestanding structure can be positioned for optimal south-facing tilt.

Updated 22 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 22 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 22 Jun 2026 Read Entry →