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

The Sunsynk 3.6kW can accept higher DC input than many owners realise, within limits.
Correct design and settings matter — otherwise potential yield is left on the table.
This guide explains practical configuration for better generation and export outcomes.

Updated 22 Oct 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 Oct 2026 Read Entry →

My Components

Sunsynk 3.6 ECCO review: best DIY hybrid I have used for G98 – 3.6kW AC, dual MPPT, battery-ready, ENA listed. Around £700-£800.
Owner since May 2023: two strings + Fogstar battery + Solar Assistant; still on the wall three years later.
Generator port proof: I have processed 6.3kW of solar at once by combining both PV strings with an extra inverter on the generator port.
Dealbreakers: 5-minute app refresh, CT clamp beyond ~15m, parallel battery SOC quirks. See also Sunsynk vs Deye.

Updated 22 Oct 2026 Read Entry →

Fundamentals

Physics page: how power optimisers recover mismatch losses from shade and mixed angles.
NREL-style gains are largest under moderate shade (about 15-18%), not on clean roofs.
Uniform cloud is weak: optimisers can even cost a little efficiency when every panel is equally dull.
Buy companion: best optimisers brand comparison.

Updated 22 Oct 2026 Read Entry →

Practical and DIY

DNO registration is G98 or G99 for generation: export payments still need a supplier process and usually an export MPAN.
3.68 kW AC single-phase is the usual G98 boundary: above that, apply for G99 before you install.
Keep a clean document pack: MPAN, inverter type-test, single-line diagram, DNO letter, EIC and Building Regs evidence.
After the DNO letter, fork to export: Octopus DIY export without MCS.
Most delays are preventable: wrong MPAN, unlisted inverter, missing diagram, or treating DNO approval as an export tariff.

Updated 22 Oct 2026 Read Entry →

Energy Utilisation

Use the calculator to estimate your numbers based on your setup.
Real-world return: £2,729 recovered in ~2.5 years from a £9,000 DIY system.
2025 outcome: £1,668 total benefit from bill reduction, arbitrage, and export.
Payback trajectory remains attractive, with newer component pricing improving today’s economics.

Updated 22 Oct 2026 Read Entry →

Energy Utilisation

Upfront cost of £6,000-12,000 is the number one blocker: 0% VAT already saves over £1,000, and a listed plug-in kit is now a far cheaper entry point, from £336.
UK weather is not the dealbreaker it looks: a battery stores the daytime surplus and the Smart Export Guarantee pays you for every exported kWh.
A typical system needs around 400 square feet of roof: walls, carports, sheds and garages count too when the main roof falls short.
Panels outlive the worry: degradation is slow and warranties run 25 years; storm-prone roofs are the real exception worth weighing.

Updated 22 Oct 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 Oct 2026 Read Entry →

Fundamentals

Start with your goal, not the hardware: bill reduction, resilience, DIY learning, and export income lead to different system designs.
Roof direction and shading decide the first cut: a simple south-facing roof is easy; mixed, shaded, or small roofs need more design work.
Batteries change the economics by moving solar or cheap-rate electricity into expensive evening hours.
DIY can save money, but compliance still matters: inverter certification, DNO notification, isolation, and safe wiring are not optional.

Updated 22 Oct 2026 Read Entry →