Upgrade Your Solar System — More Power, More Savings
Solar panel technology has advanced dramatically over the past decade. If your Cardiff home has an older solar system, upgrading to modern high-efficiency panels can significantly increase your energy generation — often by 20–40% — without needing to change your roof mounting or inverter.
GL Solar specialises in solar system upgrades across Cardiff and South Wales. Whether you want to replace ageing panels, add more panels to an existing array, upgrade your inverter, or retrofit battery storage to an existing system, our team has the expertise to maximise your solar investment.
We carry out a full assessment of your existing system before recommending any upgrades, ensuring you only invest in improvements that will deliver a genuine return.
What's Included
System Performance Audit
We assess your existing system's performance and identify where upgrades will deliver the best return.
Panel Replacement
Replace older, lower-efficiency panels with modern tier-1 panels for significantly more generation.
Inverter Upgrade
Upgrade to a modern smart inverter with panel-level monitoring and optimisation.
Battery Storage Retrofit
Add battery storage to your existing solar system to store energy for evenings and cloudy days.
System Expansion
Add more panels to your existing array to increase your total generation capacity.
Updated MCS Certification
All upgrades are MCS certified, maintaining your eligibility for SEG payments.
Our Process
System Assessment
We review your existing system's performance data, inspect panels and inverter, and identify upgrade opportunities.
Upgrade Recommendations
We present clear upgrade options with projected performance improvements and payback periods.
Compatibility Check
We verify that new components are compatible with your existing mounting, wiring and inverter.
Upgrade Installation
Our Cardiff team carries out the upgrade efficiently, minimising downtime for your solar system.
Testing & Commissioning
The upgraded system is fully tested and commissioned, with updated monitoring configured.
Updated Certification
We issue updated MCS documentation and register any changes with the relevant authorities.
Why Choose GL Solar Cardiff?
Up to 40% More Generation
Modern panels can generate significantly more than older equivalents of the same size.
MCS Certified Upgrades
All upgrades maintain your MCS certification and SEG eligibility.
Cardiff Based
Local team with fast response times across Cardiff and South Wales.
Clear ROI Analysis
We provide detailed payback calculations before you commit to any upgrade.
“Our solar system was 8 years old and not performing well. GL Solar upgraded our inverter and replaced 4 underperforming panels. Generation is up by nearly 30% and we're now earning properly from the SEG. Brilliant service from a Cardiff company that really knows their stuff.”
Frequently Asked Questions
Areas We Cover in Cardiff & South Wales
GL Solar provides Solar Panel Upgrades services across Cardiff and the wider South Wales region. Whether you're in the city centre or the surrounding valleys, our local team is ready to help.