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

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 12 Jul 2026 Read Entry →

System Guides

There is no legal maximum number of solar panels allowed in the UK: standard homes are limited by practical constraints, not panel count.
Nine 400W panels make 3.6kWp: ten make 4kWp DC and can still use a 3.68kW G98 inverter.
Allow roughly 1.9m² per panel: then leave room for roof edges, ridges, valleys and obstructions.
G98 limits inverter capacity, not panel capacity: above 3.68kW AC on single phase, obtain G99 approval first.

Updated 12 Jul 2026 Read Entry →

Practical and DIY

Most pitched-roof solar installations need scaffolding: the decision depends on height, roof pitch, access and how long the work takes.
A simple domestic scaffold typically costs a few hundred pounds: complex access, extra elevations and longer hire periods can take the cost into four figures.
The law requires commercial roof work to be properly planned: the duty includes choosing equipment that prevents falls where reasonably practicable.
Towers and roof ladders have limited uses: neither automatically provides the protected working platform needed for a full solar installation.

Updated 12 Jul 2026 Read Entry →

System Guides

UK solar panel output is strongly seasonal: June and July normally peak, while December produces the least.
Winter output is a small part of summer output: November to February cannot be treated like four average months.
A battery cannot move summer electricity into winter: size it around daily surplus, not annual generation.
PVGIS provides the useful estimate: enter your location, roof direction, angle and system size rather than relying on one UK average.

Updated 12 Jul 2026 Read Entry →

System Guides

Most UK homes have a single-phase supply, but some homes already have three phase.
G98 permits up to 3.68kW per phase, so a three-phase supply allows up to 11.04kW in total.
You can use a true three-phase inverter or, with DNO agreement, one single-phase inverter on each phase.
Three-phase solar makes most sense with a large array and substantial loads such as a heat pump and EV.

Updated 12 Jul 2026 Read Entry →

System Guides

You can have two separate solar systems on one UK property: both systems must be declared and safely connected.
The DNO assesses their combined inverter capacity: two 2kW inverters count as 4kW, so a single-phase site normally needs G99 approval.
One boundary meter records the property’s net import or export: separate solar arrays do not normally need separate export meters.
An MCS system and a DIY expansion can coexist: keep their paperwork separate and check the export supplier’s evidence requirements.

Updated 12 Jul 2026 Read Entry →

Practical and DIY

Confirm the DNO paperwork is complete: keep the G98 acknowledgement or G99 approval and commissioning records.
Register for a Smart Export Guarantee tariff: export payments do not start automatically after installation.
Set up generation and consumption monitoring: save an early baseline so you can recognise faults and changing usage.
Judge the system through its first winter: compare trends and alerts, not winter output against summer peaks.

Updated 12 Jul 2026 Read Entry →

Fundamentals

A solar inverter turns the DC your panels make into the AC your home runs on: no inverter, no usable solar electricity.
Hybrid vs string vs microinverter is a design decision, not a brand choice: pick wrong and adding a battery later can mean replacing the inverter.
Hybrid prices have fallen hard: 3-8kW hybrids now retail at £770-£1,600 and 3-6kW strings from £282 (1 July 2026 supplier crawl).
Connecting an inverter is notifiable electrical work in the UK: budget £250-plus for the electrician and expect a type C RCBO on its own circuit.

Updated 12 Jul 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 12 Jul 2026 Read Entry →