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

Automate battery charging using Solar Assistant, PV forecasts, and overnight tariff rates to maximise winter savings.
Simplest setup: charge from grid overnight on Octopus Go at 7.5p/kWh, discharge during peak hours.
Advanced: use Forecast.Solar API + Solar Assistant rules to decide whether to charge from grid or wait for solar.
Works with Sunsynk and Deye inverters via MQTT control through Solar Assistant.

Updated 24 Jul 2026 Read Entry →

Fundamentals

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.

Updated 24 Jul 2026 Read Entry →

Fundamentals

Series doubles voltage, parallel doubles amp-hours: two 50V 100Ah modules give the same 10kW either way, so the arrangement decides use, not size.
Most UK homes expand in parallel at ~48V because you can add another module later without redesigning the string or changing the inverter voltage window.
Series is for voltage problems, not capacity: a high-voltage inverter threshold, or a long cable run where less current means thinner and cheaper cable.
Parallel packs drift out of balance: the module nearest the load works hardest, and a diagonal busbar connection reduces it without curing it.
Planning is DIY-adjacent, live DC is not: sizing and unpowered rack assembly differ from AC work, the inverter battery port and the DNO process.

Updated 24 Jul 2026 Read Entry →

Practical and DIY

Updated 24 Jul 2026 Read Entry →

Energy Utilisation

Solar changes behaviour, not just bills — timing appliance use unlocks bigger savings.
Understanding your generation curve is critical for self-consumption and battery planning.
Small routine changes compound into meaningful annual cost reductions.

Updated 24 Jul 2026 Read Entry →

Practical and DIY

Honest verdict: a solar gazebo is expansion with garden value, not a free lunch on yield per panel.
My build: about £2,018 including tools for 3.28 kWp on a ~6° flat roof structure.
Flatter tilt means more panels and more cleaning where water ponds on the frame edge.
Compare roof and ground first if height safety and planning allow a better tilt.

Updated 24 Jul 2026 Read Entry →

Practical and DIY

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 24 Jul 2026 Read Entry →

Fundamentals

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 24 Jul 2026 Read Entry →

Fundamentals

Choosing a solar inverter comes down to three types: hybrid for most UK homes, string for the cheapest clean roof, microinverters for shade.
Hybrid is the default because it keeps the battery option open for around £200-300 more than a basic string unit, and it covers both G98 and G99 connections.
String inverters are simplest and cheapest on a clean unshaded roof, and only when you are certain you will never add storage, because you cannot upgrade an inverter later.
Microinverters earn their keep on awkward roofs with shading or three or more orientations, since one shaded panel no longer drags the whole string down.
Decide the type before the model: then check DNO limits, MPPT voltage window, battery compatibility and export control against your shortlist.

Updated 24 Jul 2026 Read Entry →