Solar system upgrades
Already have solar panels or a battery system and want to get more from it? This section covers every upgrade option available to UK homeowners — from adding backup power and extra storage, to protecting panels from pigeons and replacing ageing inverters.
Each guide below is independent technical advice. No installer commission, no brand tie-ins — just clear information to help you make the right decision for your system.
A solar system health check covers your current system, what it can support, and which upgrades are worth considering for your situation. We assess compatibility, costs, and return on investment before you commit to anything.
Book a System Health Check → What's included in a health checkKeep your home running during a grid outage. Four configuration types from a single EPS socket to full-house automatic changeover.
Aluminium mesh fitted around the panel perimeter to stop pigeons, starlings, and squirrels nesting underneath your solar array.
Already have a hybrid inverter and battery? Add a second or third battery module to increase your storage capacity and reduce grid import further.
Inverter failed, out of warranty, or switching to a hybrid for battery compatibility? Replacement covers supply, installation, commissioning, and settings migration.
Have solar panels but no battery? This guide covers AC vs DC coupling, inverter compatibility, DNO requirements, CT clamp changes, and realistic costs for a full battery retrofit to an existing solar-only system.
Which upgrade suits your situation?
Use this quick decision guide to identify the most relevant upgrade for your system.
Your priority is adding battery storage. Read the add battery to existing solar guide — it covers AC coupling (works with any inverter), DC coupling (needs a hybrid inverter), compatibility, and realistic costs.
Adding a second or third battery module to an existing hybrid system is usually straightforward. Read the add extra battery guide to understand compatibility, installation, and costs. GivEnergy, Sunsynk, Growatt, and most other hybrid inverters support multi-battery configurations.
You need EPS (Emergency Power Supply) capability. There are four configuration types — from a simple EPS wall socket to full-house automatic changeover. Read the EPS installation page to compare options, check inverter compatibility, and see pricing from £795 (socket) to £795 (dedicated circuit).
Bird mesh is the standard solution — aluminium mesh fitted around the panel perimeter to prevent nesting. Read the bird mesh guide for what's involved, how long it takes, and typical costs.
Inverter replacement is common after 10–15 years or following irreparable failure. Read the inverter replacement guide to understand what's involved. If you're ready to book, go directly to the inverter replacement service page.
How STS handles upgrade work
We review your current system before recommending any upgrade. No upselling — only what your system can support and what genuinely makes financial sense.
All upgrade costs confirmed in writing before any work begins. Hardware, labour, DNO applications, and commissioning — no hidden extras.
Every upgrade is tested on-site and documented in a post-installation report. You leave with a clear record of what was done and how it was configured.
Independent from manufacturers and installers: STS is not tied to any solar brand, manufacturer, or supply chain. This means the upgrade recommendation is based entirely on what's right for your system — not what's most profitable for us to sell. We work with GivEnergy, Sunsynk, Growatt, SolarEdge, Solis, Huawei, Fox ESS, and all other major UK brands.
Related services
Compatibility assessment, generation review, and upgrade recommendations. Start here if you're unsure what your system needs.
Supply, fit, commission, and document a new inverter. All major brands. Cost confirmed before work begins.
Something broken rather than an upgrade? On-site fault diagnosis and repair for all major brands.
Not sure if you have a fault or just need an upgrade? A remote diagnostic identifies the root cause before you commit to anything.
Frequently asked questions
The most common upgrades for existing UK solar systems are: adding battery storage (if you currently have solar-only), expanding battery capacity (if you already have a battery), EPS/backup power installation, bird mesh and anti-pigeon protection, and inverter replacement. Each upgrade has different requirements and costs — the right choice depends on your current system, your goals, and your budget.
Most solar systems can be upgraded in some way. The most common constraint is inverter compatibility — some upgrades (like DC-coupled battery retrofit or EPS) require a hybrid inverter. If yours is a standard string inverter, options may be more limited or require inverter replacement as part of the upgrade. A system health check can confirm what your system is capable of before you commit.
For electrical upgrades (batteries, EPS, inverter replacement), yes — you need a Part P certified electrician, ideally MCS-accredited. For non-electrical upgrades like bird mesh, any competent roofer or solar maintenance company can carry out the work. MCS accreditation is required for battery upgrades if you want to claim any applicable export tariffs or subsidies.
Costs vary by upgrade type: bird mesh £995 for small arrays, typically £995–£1,395 for most systems; EPS installation from £795 (wall socket) to £795 (dedicated circuit), up to £1,295 for full-house automatic changeover; adding an extra battery module from £2,000–£2,995 installed; inverter replacement £795–£1,200. Full battery retrofit for solar-only systems is £2,995–7,000. All costs should be confirmed in writing before any work begins.
Yes, for most electrical upgrades. Adding battery storage, replacing an inverter, or changing your system's export capacity all require a G99 variation form to be submitted to your distribution network operator (DNO). This is usually a straightforward process handled by your installer and approved automatically within 2–4 weeks. Bird mesh requires no DNO notification.
For AC-coupled battery upgrades, your existing solar inverter warranty is typically unaffected — you are adding equipment alongside it, not changing it. For DC-coupled upgrades or inverter replacement, you are replacing the inverter, so the old warranty ends and you receive a new warranty on the replacement unit (typically 10 years for a new inverter). Always check warranty terms with the original manufacturer before proceeding with any upgrade that affects existing equipment.
Not sure where to start?
A solar system health check covers your current system, identifies which upgrades are compatible, and gives you a clear, costed plan — no sales pressure, just engineering advice.