If you have a solar system on the feed-in tariff (FiT), you might think you're stuck with your original setup forever. This is one of the biggest misconceptions in solar today. Ofgem changed the rules a few years ago to allow significant system modifications while protecting your valuable FiT payments.
Many FiT customers are missing out on battery storage, higher capacity panels, and better export rates because they wrongly believe any changes will void their tariff. The reality is you can upgrade panels, change inverters, add batteries, and even increase system capacity - you just need to do it correctly.
Key Points
- You can upgrade FiT systems without losing your tariff - Ofgem changed the rules
- Allowed modifications include: new panels, different inverters, battery storage, increased capacity
- Battery storage requires a bi-directional meter to separate grid charging from solar generation
- You can switch from FiT's 50% deemed export (7p/kWh) to SEG actual metered export (typically 15p/kWh)
- Keep the generation payment part of FiT (the valuable bit) while moving export to SEG
- Alternative approach: leave FiT system untouched and add completely separate system on different roof area
Common Misconceptions
- **"Any changes void my FiT"** - False. Ofgem allows modifications with proper procedures
- **"I can't add batteries to FiT systems"** - You can, but need bi-directional metering
- **"Panel compatibility limits my options"** - There are no specific compatibility restrictions for upgrades
- **"FiT export payments are always better"** - Not necessarily. SEG often pays more than FiT's 7p/kWh export rate
- **"I need to choose between FiT generation and SEG export"** - You can keep FiT generation payments and move just export to SEG
Real-World Advice
A typical 4kW FiT system from 2012 might have panels producing less electricity than modern equivalents due to age and lower efficiency. By upgrading to current panels and adding battery storage, you could:
- Keep your original FiT generation rate (potentially 40p+/kWh)
- Store excess for evening use instead of exporting at 7p/kWh
- Export surplus at SEG rates of 15p/kWh instead of deemed 7p/kWh
The financial benefits depend heavily on your usage patterns. If you're home during the day using most of your generation, the 50% deemed export might still work better. If you export significant amounts, SEG metered export usually pays more.
UK-Specific Considerations
**DNO Notifications:** Any system changes need G98/G99 applications to your Distribution Network Operator, even for like-for-like replacements.
**Meter Requirements:** Battery systems must have bi-directional meters to prevent grid-charging showing as generation. Your FiT company needs to see import, export, and net readings.
**Energy Company Process:** Post-upgrade, you'll need to provide your energy company with system line diagrams showing whether you've used AC-coupled batteries (separate inverter) or hybrid inverters.
**MCS Certification:** Upgrades typically require new MCS certificates as proof of compliant installation.
Before You Spend Money
**Check your current FiT rate** - Higher rates make keeping the generation payment more valuable
**Analyze your export patterns** - Are you actually exporting 50% or less? This determines if SEG switch makes financial sense
**Assess roof space** - Sometimes adding a completely separate system is simpler than modifying the FiT installation
**Get proper advice** - The paperwork and meter requirements are specific. Don't risk your valuable FiT payments with incorrect installation
**Consider your usage timing** - Batteries make most sense if you're out during peak generation hours
**Budget for admin** - Allow time and potentially costs for energy company paperwork and meter changes
Frequently Asked Questions
**Q: Will upgrading my panels affect my FiT generation payments?**
A: No, you keep the same rate per kWh generated. More efficient panels just mean more kWh and higher payments.
**Q: What's a bi-directional meter and why do I need one for batteries?**
A: It separates grid electricity used to charge batteries from actual solar generation, preventing you from claiming FiT payments on grid power.
**Q: Should I switch from FiT export to SEG?**
A: Usually yes - SEG typically pays 15p/kWh for actual exports vs FiT's 7p/kWh on deemed 50%. But if you export very little, FiT's 50% assumption might pay more.
**Q: Can I do this work myself?**
A: No, you need MCS-certified installers and proper DNO notifications to maintain your FiT eligibility.
**Q: How long does the paperwork take?**
A: The energy company admin is often the longest part - technical installation treats it as a new system.
Summary
FiT system upgrades are not only possible but often highly beneficial. The key is doing it correctly with proper metering, DNO notifications, and energy company documentation. You can significantly improve your system performance while protecting your valuable FiT generation payments.
The biggest win is usually switching export payments from FiT's 50% deemed rate to SEG's metered actual rate, while keeping your high FiT generation rate intact. Combined with modern panels and battery storage, this can dramatically improve your solar investment's returns.
Don't let misconceptions keep you stuck with outdated technology. With proper professional installation, you can have the best of both worlds: valuable legacy FiT rates and modern system performance.