Solar system guides
Plain-English technical explainers for UK homeowners and installers. How solar batteries actually work. What CT clamps measure and why direction matters. What to check when your system is first installed. Written from hands-on experience, not from a marketing brief.
More guides are published regularly. If you're troubleshooting a specific fault, see Problems or Brands for fault-specific pages.
If your system has a specific fault — battery not charging, inverter offline, monitoring down — a remote diagnostic gets to root cause faster than reading guides. Most faults diagnosed in a single session.
Book a Remote Diagnostic — from £75 → Solar not working? Start hereNew solar owner
Everything you need in your first year — how your system works, how to maximise savings, maintenance basics, and what to do when something goes wrong. One hub, all the essentials.
Your starting point. Links to every guide that matters in your first year — system fundamentals, savings optimisation, maintenance, backup power, and troubleshooting.
Explore hub →Get the best financial return. Self-consumption vs export, tariff selection, battery scheduling, and the settings most people miss. Worth £200–£500/year.
Read guide →What to check monthly, quarterly, and annually. Panel cleaning, inverter ventilation, battery health, firmware, warranties, and when to call an engineer.
Read guide →Fixed vs variable, Octopus Go vs Flux vs Agile, export tariffs explained, and how to match your tariff to your battery setup for maximum savings.
Read guide →How solar and battery systems work
Understanding the fundamentals helps you diagnose problems, interpret your monitoring data, and make better decisions about your system.
Battery chemistry, BMS operation, charge cycles, round-trip efficiency, SoC vs DoD, AC/DC coupling, and why systems degrade over time. The technical foundation behind every battery fault.
Read guide →What a current transformer does, why a backwards CT clamp causes battery not to charge, how to perform the kettle test, single vs three-phase, and when to call an engineer.
Read guide →DC to AC conversion, MPPT tracking, anti-islanding protection, grid frequency response, and what happens inside the inverter when the grid voltage drops.
Read guide →Where to position grid, generation, and EV CT clamps when your home has solar, a battery, and an EV charger. The three configurations, Henley block solution, and how to test your setup.
Read guide →Why your system shuts down during a power cut even with a battery, what anti-islanding is, EPS vs UPS, how island mode works, and what you can realistically power from a battery.
Read guide →Installation and commissioning
What to look for, what to ask, and what to do when things aren't installed correctly.
What to check when your solar or battery system is being installed — roof penetrations, cable labelling, inverter location, commissioning tests, and the documentation you must receive. MCS 3002, 3012, BS 7671 referenced.
Read checklist →Why DNOs set export limits, what G98 and G99 require, how inverters enforce limits using CT clamp data, and what happens when the limit is misconfigured.
Read guide →How SEG works, which tariffs are available, what your system needs to qualify, and how to check you're being paid the correct amount for your solar exports.
Read guide →Settings resets, stalled updates, version incompatibility, and bricked hardware — what can go wrong when updating inverter or battery firmware, and how to recover.
Read guide →Which grid connection standard applies to your system, how Fast Track G99 works, timelines, and what to do if DNO registration was never completed.
Read guide →How data flows from your panels to your phone, what the key portal figures mean, why monitoring goes offline, and how to access it after buying a house with solar.
Read guide →How Flux's three-period day works, whether it is worth switching, how to configure every major inverter brand, and what to do when the BST clock shift breaks your schedule.
Read guide →Can you replace old panels with higher wattage modules and keep your Feed-in Tariff? Yes — Ofgem confirmed it. How payments are pro-rated, the step-by-step process, and when it makes financial sense.
Read guide →Step-by-step shutdown and restart procedure for maintenance, emergencies, or roof work. AC and DC isolation sequence, battery shutdown, and brand-specific notes for all major inverters.
Read guide →What fault codes mean, where to find them, how to read error logs, and when a code means you need an engineer vs when you can fix it yourself. All brands covered.
Read guide →Off-grid solar guides
Technical guides for off-grid and hybrid systems — sizing, generator integration, cold weather performance, and the settings that keep an autonomous system running through the winter.
How to size battery capacity, solar array, and backup generator for a UK off-grid property. Load profiling, days of autonomy, seasonal irradiance, and common oversizing mistakes.
Read guide →How LiFePO4 capacity drops in cold weather, low-temperature charge cutoffs, UK winter performance data, thermal management strategies, and how to prevent cold-temperature charging damage.
Read guide →Generator sizing, auto-start SoC thresholds, AC input current limits, charge profile settings, runtime balance, and Victron MultiPlus AC coupling — for reliable off-grid operation year-round.
Read guide →Looking for something specific?
Guides explain the principles. If you have an active fault, these sections get you to a diagnosis faster.
Battery not charging, inverter red light, monitoring offline, system underperforming. Fault-specific guides for the most common UK solar problems.
Browse problems →The most in-depth GivEnergy resource outside of GivEnergy themselves. 48+ pages covering faults, setup, configuration, account management, and products.
GivEnergy hub →Inverter showing an error code? Look up GivEnergy, SolarEdge, Growatt, Sunsynk, Solis, Enphase, Fronius, and Huawei fault codes with plain-English explanations.
Look up fault codes →Common questions
The most common reason is that the timed charge schedule in your inverter or portal is not set correctly, or was reset by a firmware update. Check that timed charge is enabled, the charge window matches your tariff cheap-rate hours, and the target SoC is above your current battery level. If settings look correct, a reversed CT clamp can also prevent overnight charging — the inverter cannot correctly measure grid import, so the charge control logic misfires. See our CT clamps guide and battery not charging for full diagnosis steps.
A CT clamp (current transformer) is a sensor that measures electrical current. On a solar system, CT clamps tell the inverter how much power is being imported from or exported to the grid. If the CT clamp is installed backwards, or on the wrong cable, the inverter receives incorrect data — leading to the battery not charging, the system exporting when it should import, or monitoring showing wrong figures. Most CT clamp issues can be diagnosed remotely using your monitoring data. See the CT clamps guide for the full technical explanation.
Most LiFePO₄ batteries are rated for 4,000–6,000 charge cycles at 80% depth of discharge — roughly 10–15 years of daily use. The main factors affecting lifespan are depth of discharge (shallower cycles = longer life), operating temperature (batteries degrade faster above 35°C or below 5°C), and charge rate. GivEnergy offers a 12-year warranty on their battery modules. See how home battery storage works for the full technical picture.
Key checks include: roof penetrations are sealed, all isolators are correctly labelled, the inverter is mounted in a ventilated location away from direct sunlight, the WiFi dongle is connected and reporting, export limitation is configured if your DNO requires it, the installer runs a full generation test before leaving, and you receive your MCS certificate, G98/G99 notification reference, electrical installation certificate, and system user guide. See the full installation day checklist for every item with its relevant standard.
Yes — the technical guides cover principles that apply across all brands. Battery chemistry, CT clamp physics, and installation standards are the same whether your system is GivEnergy, Solis, SolarEdge, Growatt, or Sunsynk. Where brand-specific settings or behaviours differ, the guides note this and link to the relevant brand page. For brand-specific fault diagnosis, see the Brands section or Fault Codes.
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