Frequently Asked
Questions

Check three things: 1) System age (10+ years suggests upgrading consideration), 2) Generation performance (if your bills have increased despite similar usage, panels may be degrading), 3) Inverter status (error codes or complete failure indicates replacement needed). Use our decision tool for a personalised assessment.

Solar panels typically last 25–30 years in Scotland, but efficiency degrades by approximately 0.5% per year. After 15 years, you've lost about 7.5% efficiency. Panels from the early Feed-in Tariff era (2010–2015) are now reaching the point where replacement can make financial sense, especially with 0% VAT until March 2027.

Inverters typically last 10–15 years. Warning signs include: error codes on the display, complete shutdown, significantly reduced generation (inverter efficiency drop), overheating, or unusual noises. If your inverter is 10+ years old and showing any of these signs, replacement is recommended. Modern hybrid inverters cost £1,200–£2,500 installed.

Yes. Most modern hybrid inverters support 5–15kWh of battery storage. If you're replacing your inverter anyway, it's the perfect time to add a battery — you only pay for one installation visit. We typically recommend Duracell Dura5 (5.32kWh stackable) or GivEnergy AIO (9.5kWh).

Adding a battery or replacing your inverter DOES NOT affect your FiT payments — these are protected upgrades. However, replacing your solar panels or significantly increasing capacity may invalidate your FiT contract. Always check with your FiT provider before replacing panels.

Inverter replacement costs £1,200–£2,500 installed, depending on size and brand. With 0% VAT (active until March 2027), you save approximately £240–£500. Installation takes 2–4 hours. You'll get a 10-year warranty on the new inverter and modern monitoring features.

Usually no — if the panels still generate well. At 10 years, panels have only lost about 5% efficiency. However, if your inverter is failing AND you want to add battery storage, a combined upgrade makes sense. If panels are degraded AND the inverter is failing, full replacement may be the best ROI — especially with grants and 0% VAT.

Full system replacement (panels + inverter + battery): £12,000–£18,000 installed. With 0% VAT, you save £2,400–£3,600. Rural Scottish homes may qualify for an additional £18,000 HES grant (£9k grant + £9k loan) when combined with a heat pump, potentially reducing net cost to under £5,000.

HES offers grants for battery storage when installed with heat pumps. Rural homes: £9,000 grant + £9,000 loan. Urban homes: £7,500 grant. The standalone solar PV grant is no longer available.

Yes, 0% VAT on solar panels and battery storage is active until 31 March 2027. Automatic savings of £700–£3,600 depending on system size.

They're essentially the same thing. "Retrofitting" typically means adding a battery to an existing solar system without changing anything else. "Upgrading" can mean battery addition, inverter replacement, or both. Both use AC-coupled batteries that work with any existing system.

Compare your current generation to your first year of operation (check old bills or FiT statements). Panels degrade about 0.5% per year. If you've lost more than 10% in 10 years, degradation is faster than expected. Also check for: physical damage, discolouration, micro-cracks, or shading from tree growth.

For Scotland, we recommend: 1) Duracell Dura5 (our top choice — 15yr warranty, LiFePO₄, stackable, AC-coupled), 2) GivEnergy AIO (9.5kWh, strong UK support), 3) Tesla Powerwall 3 (premium option but limited Scotland installers). All are AC-coupled and work with existing FiT systems.

With Octopus Agile and a smart battery, you can: charge overnight at 7–15p/kWh, use stored power during the day, and export during evening peaks at 20–40p/kWh. Typical additional savings: £200–£400/year on top of standard solar savings. Requires a compatible smart inverter.

Yes. Several UK banks offer green mortgages for energy efficiency improvements: Barclays Greener Home Reward (£1,000 cashback), Nationwide Green Additional Borrowing (preferential rates), Halifax Green Living Reward (£2,000). Combined with 0% VAT and HES grants, this can reduce upfront costs to near zero.

Replacing panels with the same or lower capacity usually preserves FiT payments, but you MUST notify your FiT provider first and get written approval. Increasing capacity will likely end your FiT contract. Battery addition and inverter replacement do NOT affect FiT — these are protected upgrades.

Inverter replacement only: 2–4 hours. Battery addition: 1 day. Full system replacement (panels + inverter + battery): 2–3 days. Total process from quote to completion: 2–4 weeks including survey, design, and installation scheduling.

Usually no. Solar panel upgrades are typically permitted development in Scotland, provided: panels don't protrude more than 200mm from the roof, not on a listed building, not in a conservation area, and not visible from the street (for conservation areas). Battery systems are usually permitted if installed inside or in an outbuilding.

AC-coupled batteries connect to your existing system via a separate inverter — they work with ANY existing solar setup (including FiT systems). DC-coupled batteries connect directly to the solar panels via a hybrid inverter — more efficient but requires replacing your existing inverter. For upgrades to existing systems, AC-coupled is almost always the right choice.

Yes. Studies show solar + battery systems add 2–4% to property values. With Scottish homes averaging £200,000, that's £4,000–£8,000 added value for a £5,000–£7,000 battery installation. The bigger benefit is improved EPC rating (often from D to B or C), making the property more attractive to buyers.