Ask Lumos is a series from Lumos PV, answering the questions we get asked most often about solar, batteries and home energy. Based on Worton Park, Oxfordshire, we work with homeowners, businesses and community organisations across Oxfordshire and the Cotswolds. Visit our Resources Hub to view some of our recent projects.
Energy storage is one of the fastest-growing areas of the renewable energy market, and it is not hard to see why. Whether you are already generating your own solar power or simply looking for a smarter way to manage your energy costs, a home battery can make a real difference to how much you spend on electricity.
Here is everything you need to know.
How does a home battery work?
A home battery stores electricity so that you can use it at a time that suits you, rather than at the moment it is generated or drawn from the grid.
If you have solar panels, your battery will charge during the day when your panels are producing more electricity than your home needs. You can then draw on that stored power in the evening, overnight, or on cloudy days, rather than buying electricity from the grid at a higher rate.
Without solar panels, a battery can still save you money. By charging overnight on a time-of-use tariff, when electricity is cheapest, and discharging during peak hours when rates are higher, you can significantly reduce your bills. Tariffs like Octopus Go and Intelligent Octopus Go are designed with exactly this kind of flexibility in mind.
Most home batteries connect to your existing electrical system and are managed by a smart inverter or energy management system, which takes care of when to charge and discharge automatically.
Battery myths
You need solar panels to benefit from a battery: Not true. While solar and battery storage work brilliantly together, a standalone battery can still deliver meaningful savings if you are on the right tariff. The payback period will typically be longer without panels, but many homeowners find the combination of lower bills and greater energy independence more than worth it.
Batteries are too big and intrusive: Modern home batteries are compact wall-mounted units, roughly the size of a large fuse box. Brands like GivEnergy, which Lumos PV install as a preferred supplier, are designed to sit neatly in a garage, utility room or even a hallway.
They are not safe: Home battery systems installed by accredited professionals are safe, reliable and designed to last. MCS-accredited installers like Lumos PV follow strict industry standards on installation and commissioning, so you can be confident the system is set up correctly from day one.
They do not last long enough to be worth it: Most modern home batteries carry a warranty of around ten years, with many systems expected to perform well beyond that.
How much energy can a battery store?
Battery capacity is measured in kilowatt-hours (kWh). To put this in context, the average UK home uses around 8 to 10 kWh of electricity per day.
A typical entry-level home battery sits at around 5 kWh, which would cover roughly half of an average household’s daily usage. A 10 kWh battery could, in the right conditions, cover a full day’s consumption. Many systems are modular, meaning you can add capacity over time as your needs change or budget allows.
To give a practical example: a 10 kWh battery, charged overnight on a cheap tariff, could power your lighting, fridge, TV and phone charging through the following evening without drawing from the grid at peak rates. Add solar panels, and you could cover the vast majority of your daily usage without touching the grid at all for much of the year.
What can you expect to save?
Savings vary depending on your energy usage, your tariff, and whether you have solar panels. As a rough guide, a battery paired with solar can save a typical household anywhere from £500 to £1,000 per year, depending on system size and usage patterns. The payback period for a combined solar and battery system is typically in the region of seven to ten years, with panels now at their lowest ever price point.
A standalone battery, used with a time-of-use tariff, can save in the region of £200 to £500 per year. Payback will take longer, but the ongoing savings are real and, as energy prices remain volatile, increasingly compelling.
The sooner a battery is installed, the sooner it starts working for you.
Where can a battery be installed?
Most homes are suitable for battery storage. The battery itself needs to be installed in a dry, ventilated indoor space, such as a garage, utility room or cupboard, and should be located close to your consumer unit to keep installation straightforward and costs down.
At Lumos PV, we have installed batteries across a wide range of properties in Oxfordshire and the Cotswolds, from standard three-bedroom semis to larger rural properties, commercial buildings and community projects. If you are unsure whether your property is suitable, our team will assess this during an initial survey.
How much does a battery cost, and how can I fund it?
The cost of a home battery system depends on the capacity you need and whether it is being added to an existing solar system or installed as a standalone unit. As a guide, a 10 kWh battery system, fully installed, typically costs in the region of £4,000 to £7,000.
Battery storage is not currently subject to VAT, which keeps the upfront cost lower than it might otherwise be.
On funding, the government’s Warm Homes Plan, formally launched in January 2026, includes low and zero interest loans to help homeowners fund green home improvements including battery storage. The Consumer Loan Scheme is expected to launch in April 2027 through banks and mortgage lenders, with eligibility details still to be confirmed. It is worth keeping an eye on developments here, and we will share updates as they are announced.
Some energy tariff providers also offer incentives for battery owners, and it is worth exploring what is available through your current supplier.
What next?
If you would like to explore whether a home battery is right for your property, our team would be happy to talk it through. And if you are also considering solar panels, our Ask Lumos guide to how solar PV systems work is a useful companion read.
Lumos PV are based in Worton, just outside Oxford, and work across Oxfordshire and the Cotswolds, with experience across domestic, commercial and community projects. Get in touch to arrange a survey, or use our cost calculator for an initial estimate.
