A UK household with three children and annual electricity use of 15,000 to 20,000 kilowatt hours, roughly five times the national average, installed a battery-only storage system costing around £8,000 and then returned two months later to check the numbers. Before the install, daily electricity costs ran between £10 and £15, coming to around £300 a month. Afterward, on days when the system is also charging an EV overnight, daily costs dropped to around £5.50. The system consists of four Juracell Jura 5 modules, each storing 5.12 kilowatt hours, giving the home about 20 kilowatt hours of total storage. No solar panels, no roof work, no scaffolding. Installation was completed in roughly half a day. The system charges during off-peak hours on an Octopus Energy smart tariff, then runs the house during daytime when grid rates are higher.
The Jura 5 units use lithium iron phosphate chemistry and are rated at 1C, meaning each module can discharge its full capacity in one hour. That is twice the speed of many older or budget systems rated at 0.5C, and it matters for households running large appliances like tumble dryers or air conditioners, since the battery can supply the load without needing grid backup. The system is also weatherproof at IP65 and rated for operation down to minus 10 degrees Celsius, so units can go outside if indoor space is limited. The Juracell G3 inverter, also newly installed here as one of the first UK deployments, supports up to 10 kilowatts of solar input through two independent inputs, meaning the homeowner can bolt on panels at any point without replacing the inverter. The system coordinates automatically with the Octopus tariff to charge during the cheapest window.
The homeowner also has a 7-kilowatt Tesla wall charger running on a separate circuit. During off-peak hours, the home batteries and the car charge from the grid simultaneously without interfering with each other. The savings work out to roughly £8 per day on average, which projects to around £2,800 to £2,900 per year. At that rate the system pays for itself in around two and a half to three years. The Juracell batteries are rated for 8,000 cycles, which translates to roughly two decades of daily use. The homeowner plans to add around 28 solar panels in spring once the weather allows, which the existing inverter can handle without modification. For comparable reference, a 10 kilowatt-hour battery-only system for an average household using around 3,500 kilowatt hours per year typically costs around £5,200.
Bottom line: Battery-only storage works, but the savings scale with usage. For a high-consumption household on a smart tariff, the payback here is fast and the path to adding solar later is straightforward. Lower-consumption homes will see more modest returns.