If your solar panels are more than a decade old, chances are they’re not working as efficiently as they once did—and with today’s solar technology offering much higher output and sleeker designs, many UK homeowners are starting to ask:
“Can I upgrade my solar panels and still keep my Feed-in Tariff (FIT) payments?”
The good news is: yes, you can.
But there are some important conditions to be aware of. In this article, we’ll explain how upgrading your solar system works, how it affects your FIT tariff, and what happens to any additional energy your new system generates.
Thinking of upgrading your system? Explore our solar panel upgrade service to get started.
Why Upgrade Your Solar Panels Now?
1. Older Panels = Lower Output
Solar panels installed 10–15 years ago were typically rated around 250W per panel. Today’s modern panels can generate 400W to 500W+, meaning:
- You can get the same output with fewer panels, or
- Use the same roof space to double your system’s capacity
2. Performance Drops Over Time
Like any tech, solar panels degrade. Even if your system still works, you might notice it’s not delivering the energy it used to.
If that’s the case, it’s time for a check-up—book a service with Fit Solar to assess your system’s health.
3. Modern Aesthetics and Efficiency
Newer panels not only perform better—they look better, too. Slimmer, all-black designs are more discreet and can blend in better with your roof.
If your solar system feels outdated, it might be time for a professional check-up to explore your upgrade options.
Can I Keep My Feed-in Tariff (FIT)?
Yes, you can keep your existing FIT tariff when upgrading your solar panels—as long as your original system remains identifiable and you don’t replace it entirely.
Here’s how it works:
You keep your FIT payments on the original system
If you upgrade by adding more panels or replacing faulty components, you’ll still receive FIT payments for the original system size and its generation/export amounts.
Any additional capacity falls under the Smart Export Guarantee (SEG)
If your upgraded system produces more electricity than your original system did, that extra energy is eligible for the SEG, not the FIT.
The SEG is the new scheme that pays you for surplus energy exported to the grid—rates vary by supplier, but you can still earn money on the additional output.
Real Example: What an Upgrade Looks Like
Let’s say you originally had a 4kW system installed in 2012, with panels producing 250W each.
After years of use, the system’s performance has dropped, and you decide to upgrade to newer 500W panels.
- Your original FIT payments remain for the 4kW system
- If you add more panels and increase the system to 6kW, the extra 2kW falls under SEG
- Your system now produces more energy overall—and you’re paid for both streams
A well-planned upgrade gives you the best of both worlds.
Download our FREE guide
Choosing to power your home with solar energy is a major decision, and there's a lot to think about – from the financial investment to the technical details and the installation process.
We've compiled a list of the 8 most important questions you should ask any solar installer to ensure you make an informed decision.
Things to Consider Before Upgrading
- Check with your FIT provider before making changes
- Keep records of your original system and any modifications
- Ensure your installer is MCS certified, like Fit Solar, to maintain scheme eligibility
- Understand that system changes must be properly documented
Upgrading doesn’t have to be complicated—our team at Fit Solar handles the process from start to finish, ensuring you stay compliant and get maximum benefit from your improved system.
Ready to Upgrade? Fit Solar Can Help
We specialise in upgrading older solar systems across the UK—whether we installed it originally or not.
Here’s how we help:
- Assess your system’s current health
- Recommend higher-efficiency panels
- Advise on how to retain your FIT while boosting overall output
- Handle all MCS certifications, DNO applications, and SEG registrations
Explore your upgrade options here: Can You Upgrade Existing Solar Panels?
Conclusion: Yes, You Can Upgrade and Keep Your FIT Tariff
Upgrading your solar panels is a great way to modernise your system, generate more energy, and increase your savings—without losing your Feed-in Tariff.
At Fit Solar, we make the process simple, transparent, and fully compliant. Whether you're looking to replace ageing panels, increase output, or integrate battery storage, we’re here to help.
Want to find out what an upgrade could do for your home?
Contact us today to arrange a system review or request a quote.
