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

Start small Plug-in solar Rules, kit, costs, and what 800W can actually do. Buy well Panel prices Current UK prices and what is changing in 2026. Level up Batteries When storage makes sense, and when it is dead money.

Latest field notes

Practical and DIY

Home Battery Installation in the UK: From Quote to Handover

Home battery installation starts with a survey: agree the design, grid route, tests and handover before ordering.
Octopus battery-only installs start at £3,947 for 5 kWh: 10 kWh starts at £5,336 and a Tesla Powerwall 3 at £7,999, checked September 2026.
DNO, MCS, VAT and building control are separate: ask who handles each step and which evidence you will receive.
Commissioning must prove the settings and functions: watch charging, discharging, monitoring and any paid-for backup work.
Keep the electrical certificate and network evidence: add MCS, Building Regulations and warranty records where applicable.

Updated 27 Sep 2026 Read Entry →

Practical and DIY

Solar Panel Kits for Sheds UK: How to Size an Off-Grid Kit

Solar panel kits for sheds must be sized for winter use: a 100 W panel averages about 118 Wh per December day in our central England roof example.
Add daily watt-hours before buying: watts multiplied by hours gives each device’s daily energy use.
Check what the kit includes: a low-price panel bundle may omit both the battery and the inverter.
A small kit is a poor heater supply: a 2,000 W heater used for two hours needs 4,000 Wh.
Choose a house cable for dependable power: daily heat, refrigeration or office work needs supply through dark spells.

Updated 27 Sep 2026 Read Entry →

Fundamentals

Batteries for Solar Panels: Types, Sizing and Costs (UK 2026)

Most UK homes need 5 to 10 kWh of battery storage: your daily use and how much you shift off peak decide the number, not your roof.
AC-coupled or DC-coupled decides what you can retrofit: AC-coupled bolts onto solar that already works and loses 10-15% round trip; DC-coupled is 95-97% efficient but needs a hybrid inverter.
Only one UK brand publishes a checkable price: Fogstar Energy at £109-121 per usable kWh (24 July 2026), against roughly £700-780 per kWh for an installed all-in-one. Everything between is inferred.
Check the C-rate before the capacity: a 5 kWh battery at 0.5C delivers 2.5 kW, which runs lights and a fridge but not an oven.
GivEnergy went into administration on 9 April 2026: warranties and app support are not being honoured, so treat any remaining stock as unwarranted.
The whole case is one spread: 26.11p/kWh to buy against 12p at best to export, so every stored kWh is worth the difference.

Updated 27 Sep 2026 Read Entry →

Practical and DIY

Solar Panels on a Shed or Garage Roof UK: Wiring and Options

Check G98 headroom first: a 4-panel garage array usually fits under 3.68kW AC if it is the only inverter on site.
Hardwire unless the kit is on the register: shed solar normally needs its own breaker via a registered electrician. Since 27 August 2026 a listed plug-in kit may use a suitable socket, one per household.
Prefer AC cable runs from a local inverter to the house consumer unit over long DC strings.
With a battery, ROI can fall under 3 years on a well-used base load.
A summer house used as an office pays back faster because daytime load matches generation.

Updated 27 Sep 2026 Read Entry →

An image of a server rack type battery comprising of 3 battery units in a server rack. The door is pen and we can see the batteries inside.

My Components

Fogstar 15kWh Battery: 3-Year Owner’s Review

After 3 years, my Fogstar packs report 87.5Ah to 89.3Ah of a rated 100Ah: about 0.018Ah lost for each counted cycle.
The three packs share the work evenly: since September 2024, each counted 367 to 372 cycles and lost 6.7Ah to 6.8Ah.
The pack that worked alone for a year is 1.7Ah behind: it arrived with about 95 extra cycles, and the gap has not grown since.
Octopus Go and Solar Assistant automation saved £1,668 in 2025: my exact charge settings are in the article.
Uneven charge readings came back together: a BMS firmware update and an overnight discharge limit fixed them in my system.

Updated 26 Sep 2026 Read Entry →

Practical and DIY

Where Can a Home Battery Go in a UK House?

A home battery belongs in a garage, outside or a fire-separated utility room, not a loft, bedroom or escape route: PAS 63100:2024 and BS 7671 Amendment 4 set the rules.
A loft is expressly excluded: PAS 63100 rules out lofts, roof spaces and voids, and joist loading and summer heat make the case worse.
Outside is the preferred spot: it keeps a fire off the living space, but the enclosure must sit 1 m from windows and doors, 2 m from stored fuel, and cope with winter cold.
Indoors needs fire separation, ventilation and detection: a utility room with about 30 minutes of fire separation works; a sealed cupboard, bedroom or hallway does not.
Make the installer justify the location in writing: the exact spot, its fire separation in minutes, ventilation, Grade D2 detection and the manufacturer temperature limits, before you sign.

Updated 26 Sep 2026 Read Entry →

Practical and DIY

DIY Home Battery UK: What You Can Do Yourself

A DIY home battery is legal in the UK, but not a plug-in job: you can size, source and configure it. Fixed wiring and grid connection need an installer.
There are four rungs, and assisted DIY is the useful one: you choose the battery and inverter and keep control, while a professional designs, connects and certifies the fixed installation.
Fogstar rack batteries came to £109-121 per usable kWh on 24 July 2026: the only UK brand I can price first-party, against roughly £189 for reseller-reported Pylontech.
My own 15kWh Fogstar and Sunsynk system shows both sides: I control monitoring and automation, yet Solar Assistant still reports the wrong capacity register for these packs.
Do not DIY a closed premium system: approved commissioning, the gateway, app access and warranty responsibility are the product, not accessories around it.
Separate the rules from the commercial consequences: Building Regulations, the DNO route, MCS, SEG, VAT, warranty and insurance are related but decided separately.

Updated 26 Sep 2026 Read Entry →

Practical and DIY

Take Total Control of Your Sunsynk With Solar Assistant Rules

Solar Assistant + Sunsynk automation: Schedule charge and discharge current limits your inverter’s native app can’t handle.
Force solar export: Drop Max Charge Current to 2A during the day so surplus solar goes straight to the grid on Octopus Go.
Real UK export data: These rules helped double grid export from 1,766 kWh to 3,914 kWh year-on-year.
Crash-proof your setup: Never set amps to zero. Solar Assistant can crash and leave values stuck.
Home Assistant solar integration: Bridge Sunsynk data via MQTT for Octopus Agile pricing, solar forecasts, and EV diversion.

Updated 26 Sep 2026 Read Entry →

Fundamentals

Is Plug-in Solar Legal in the UK? Rules, Kits & Limits (2026)

Plug-in solar is legal in Great Britain since 27 August 2026: 70 kits are listed Compliant on the ENA register, and Screwfix, City Plumbing and Argos all range them, from £336.
Only listed models count: the Amazon kits with a UK plug are unlisted or Non-compliant, and battery kits are excluded by the law itself.
Not every home is suitable: the IET and Electrical Safety First say a Type AC RCD rules a home out, and only 25% of adults know which type they have.
One device per household is now written into G98: the August 2026 amendment says connecting more than one “is not allowed”, so the per-circuit relaxation did not happen.
Realistic savings are £43 to £84 a year, not the government’s “up to £110”: 650 to 800 kWh, 25 to 40% self-consumed, £0 export. Payback 7 to 14 years on the £599 kit.
Already have roof solar? The 3.68 kW limit is cumulative per property, and G98 now says so for plug-in kits in terms.

Updated 23 Sep 2026 Read Entry →

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