Eight million UK flats have no practical way to install solar panels. Until now, that is. The SolShare 2 battery system, developed by Australian company Allume Energy, changes the maths for apartment dwellers who want to cut bills and raise their EPC rating.
As reported by The Eco Experts, the SolShare 2 is a smart controller that distributes solar energy from a single rooftop array to individual flats in a block. Each flat gets its own battery allocation and smart meter, so households only pay for what they use — and can sell surplus back to the grid.
Who qualifies — and who doesn’t
The system works for any multi-occupancy building with a roof that can support solar panels: purpose-built flats, converted houses, and even blocks with shared ownership. Each flat needs its own electricity meter, which most already have. The building must have enough roof space for the number of flats — roughly 3–4 panels per flat, or about 6–8 m² of south-facing roof per home.
What this misses: blocks with north-facing roofs, heavy shading, or listed building status may still be excluded. Landlords must also give permission, and leasehold agreements often require a majority vote among residents. The catch is that even the best technology cannot fix a roof that gets no sun.
What it costs a typical flat owner
Allume Energy has not published UK pricing, but Australian installations suggest £3,000–£5,000 per flat for the full system — panels, battery, and controller. That compares with £5,000–£8,000 for a standalone home system of similar capacity. The saving comes from sharing the inverter, battery, and installation labour across multiple flats.
Ofgem’s typical flat uses 2,500 kWh of electricity per year. A 1.5 kW solar system (about 4 panels) can generate 1,350 kWh annually — covering 54% of usage. At current price cap rates (24.5p/kWh), that saves £330 a year. The battery lets households use that power in the evening, avoiding peak grid rates that can hit 35p/kWh on time-of-use tariffs.
EPC impact and grant eligibility
Solar panels and battery storage can raise an EPC rating by up to two bands for a flat, depending on current insulation and heating. A flat moving from EPC D to C gains access to cheaper green mortgages and higher rental yields. Landlords, in particular, should note that minimum EPC C will apply to new tenancies from 2028 in Scotland and is under consultation in England.
Grants that may help: the Great British Insulation Scheme covers solar PV for some households, but eligibility depends on income and property type. ECO4 includes solar panels for low-income households in off-gas areas. The Smart Export Guarantee pays 5–15p per kWh exported, which for a typical flat could add £60–£90 a year. No specific grant yet covers the SolShare controller itself, but the Department for Energy Security and Net Zero has signalled interest in multi-occupancy solutions.
What to do next
Flat owners should first check their building’s roof orientation and shading using a free solar calculator. Then approach a certified installer — the Microgeneration Certification Scheme (MCS) lists those qualified for multi-occupancy systems. Ask for a quote that breaks out the SolShare controller cost separately. If you rent, ask your landlord to consider the system as an EPC improvement; the payback period of 8–12 years is shorter than most boiler upgrades. Applications for ECO4 and GBIS grants are open now, but funding is limited and expected to tighten after the next Spending Review in March 2025.
Frequently Asked Questions
No. You need the landlord's written consent, as the system requires roof access and alters the building's electrical infrastructure. Some landlords may agree if the system improves the EPC rating and property value.
Yes, but the existing system must be compatible. The SolShare 2 can integrate with most modern inverters and batteries. An MCS-certified installer can assess compatibility during a site survey.
