Frequently asked questions

A Duracell Dura5 (5.32 kWh) typically costs £3,500–£4,500 installed, including 0% VAT (active until 31 March 2027). A Tesla Powerwall 3 (13.5 kWh) costs £8,500–£10,500. These are illustrative ranges — a free survey gives your exact figure. Prices checked August 2026.

No. Adding a battery or replacing your inverter does not affect your FiT payments — these are protected upgrades. Only replacing panels or increasing capacity may affect your FiT contract. Always confirm with your FiT provider before replacing panels. Source: Ofgem FiT guidance, checked August 2026.

Yes — HES uses a two-stream model. Clean heating grant: £7,500 (£9,000 rural). Energy efficiency grant: £7,500 (£9,000 rural). Maximum combined grants: £15,000 (£18,000 rural). An optional interest-free loan of £7,500 per stream is also available — the rural uplift does not apply to loans. Total for a rural home with one grant plus loan: £9,000 + £7,500 = £16,500. The standalone solar PV grant stopped on 6 June 2024. The Boiler Upgrade Scheme (BUS) covers England and Wales only. ECO4 is open until 31 December 2026.

Five signs: error codes on the display, complete shutdown, significantly reduced generation, overheating or unusual noises, and the monitoring app has stopped updating. If your inverter is 10+ years old and showing any of these, replacement is recommended. A modern hybrid inverter costs £1,200–£2,500 installed.

AC-coupled batteries connect via a separate inverter and work with any existing solar setup (including FiT systems). DC-coupled batteries connect directly to 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, 0% VAT on solar panels and battery storage is active until 31 March 2027. This is automatic — you do not need to apply. Typical savings: £700–£2,000 on battery upgrades, £2,400–£3,600 on full system replacements. Source: HMRC, checked August 2026.

Battery only: 1 day. Inverter replacement: 2–4 hours. Full system replacement: 2–3 days. Total process from enquiry to completion: 2–4 weeks including survey, design, DNO notification, and installation scheduling.

Yes. Surplus electricity exported to the grid earns you income via the Smart Export Guarantee (SEG), which pays 1p–25p/kWh depending on your supplier and tariff. The Outgoing Octopus flat rate is 12p/kWh from 1 March 2026. With a battery, you store surplus for evening use and export only what you truly cannot use. Source: Octopus Energy, checked August 2026.

Usually no. At 10 years, panels have lost only about 5% efficiency (0.5% per year). However, if your inverter is failing AND you want battery storage, a combined upgrade makes sense. If panels are significantly degraded AND the inverter is failing, full replacement may be the best return — especially with 0% VAT and HES grants.

Usually no. Solar panels are typically permitted development, provided: panels do not protrude more than 200mm from the roof, the building is not listed, the property is not in a conservation area with panels visible from the street. Battery systems are usually permitted if installed inside. Conservation area and listed building consent is a separate process — we check before you commit.

Installation is carried out by Home Heating Services (Scotland) Ltd (company number SC484353). They are MCS certified (IAA10151) for Solar PV, Battery Storage, and Air Source Heat Pumps, TrustMark registered (3559930), and Gas Safe registered (559575). Scottish Energy Efficiency is the advisory business — we assess, recommend, and arrange.

Three layers: workmanship guarantee from the installer (5–10 years), manufacturer warranty (15 years on Duracell Dura5, 10 years on Tesla Powerwall 3, 25–30 years on panels), and an insurance-backed guarantee via TrustMark. The IBG protects you even if the installer were to cease trading.