*SPECIAL MINI SERIES* Episode 6 of 6 Solar as Infrastructure, Data as the Foundation

Part of the podcast series bringing Healthy Homes Hub and Energiesprong UK's playbook, 'Deploying Innovative Retrofit Funding Models in the Social Housing Sector' (also available as an audiobook), to life, on how a free app built on smart meter data cuts bills before any hardware is installed, and why that is what keeps Metis's zero upfront cost solar and battery offer affordable to run. 

Host: Emily Braham, Director, Energiesprong UK 

Guest: Tom Woolley, Director of Low Carbon, Residential, Metis 

At a Glance 

• A free Energy Insights app, built on smart meter data residents already pay for, reduces bills by 9 per cent before any retrofit through behavioural nudges alone, and drove an 85 per cent conversion rate to Metis's paid solar and battery subscription in one deployment, keeping acquisition costs, and the subscription fee, low. 

• Metis funds, owns and maintains solar, battery and heat pump assets on a 25 year term at no upfront cost to the landlord, and needs no airspace lease or charge on the property, which is what lets it deploy quickly across mixed tenure stock and flats. 

• Residents can expect a gross saving of around £1,150 a year from day one, based on the average reduction recorded across Metis's deployed systems, with a net benefit of £300 to £400 after a typical £60 a month landlord subscription fee, plus the option for landlords to monetise pooled battery capacity as a virtual power plant and choose whether to share that revenue with residents. 

Metis's route to a low acquisition cost starts before any hardware is installed. A free Energy Insights app, built on smart meter data that residents already pay for through the national metering system, shows a household how it currently uses energy and offers behavioural nudges, such as flagging appliances left running or comparing usage to similar homes. On its own, without any retrofit, the app has reduced bills by 9 per cent. In one deployment where the app was rolled out ahead of the retrofit offer, 85 per cent of residents who used it went on to take up the paid solar and battery subscription, a conversion rate that keeps the cost of acquiring and engaging customers low, and that in turn is what keeps the subscription fee affordable. 

The underlying commercial structure is designed to be as simple as possible. Metis, part of the SMS group, funds solar, battery and heat pump installations from its own capital, owns the assets for a 25 year term and is responsible for their maintenance, warranty and eventual replacement, including the battery and inverter typically around year ten to twelve. No government subsidy or capital contribution from the landlord is required. Because Metis does not need an airspace lease or a charge on the property, only permission to access and maintain the assets, the contractual conversation is short enough to be deployed across mixed tenure stock, including blocks of flats, at a pace not usually possible with retrofit finance that requires more complex legal structuring. 

Residents can expect a gross saving of around £1,150 a year from day one, based on the average reduction recorded across Metis's deployed systems, made up of free generation used at the point of use plus arbitrage from storing cheap grid power for use at peak times. The saving is not tied to how much a resident uses the system, so it applies to low and high consuming households alike, and it works for customers on prepayment as well as standard credit, with typical top ups falling from around £100 to £10 a month once the system is in place. An independent, Ofgem governed switching engine also identifies the best available tariff for each resident, though switching remains optional; around 98 per cent of customers switch to the recommended tariff within six months, once any existing debt with their current supplier allows it. 

For the landlord, the offer becomes a monthly subscription, typically £60 a home, against a solar and battery installation that would otherwise represent a five figure capital cost. That leaves a net benefit for residents of £300 to £400 a year once the subscription is accounted for, and the landlord can choose whether to recover some or all of the subscription cost through a home comfort charge or absorb it as an operating cost. Electricity generated and stored on site benefits from zero rate VAT, with only grid bought top up energy charged at the standard 5 per cent domestic rate. Pooling batteries across a landlord's stock also creates a virtual power plant that Metis can operate and monetise, with any additional revenue available for the landlord to pass to residents or retain for overheads. 

The closing advice for a provider new to this is to move at pace. Rising price caps and higher resident engagement with energy costs are treated as reasons to act now rather than wait, with the simplicity of the commercial structure, no airspace lease, no landlord capital and no reliance on grant tranches, positioned as what makes rapid deployment achievable across a housing stock. 

Practical steps for housing providers 

• Ask whether a proposed retrofit finance model needs an airspace lease or a charge on the property, since removing that requirement is often what allows a landlord to move quickly across a large or mixed tenure stock. 

• Check whether resident engagement tools, such as an app built on existing smart meter data, are available ahead of a retrofit offer, since pre-existing engagement can lower acquisition costs and improve take-up. 

• Confirm whether a proposed saving is tied to a resident's level of consumption, and whether it works equally for prepayment and credit customers, so the offer reaches the households that need it most. 

• Establish exactly what a subscription fee covers, including asset maintenance, warranty and eventual replacement, and who is responsible if a battery or inverter fails. 

• Ask whether landlords can choose how any subscription cost is recovered, for example through a home comfort charge, an operating cost, or a mix of the two, and how much flexibility residents have if their circumstances change. 

• Consider whether pooling assets such as batteries across a housing stock could create an additional, monetisable revenue stream, and how any such revenue would be shared with residents. 

• Treat rising energy costs and improved resident engagement as reasons to move at pace, rather than waiting for the next funding cycle or compliance deadline to force the decision.