Are solar batteries worth it in the UK?

Solar panels only make power while the sun's up. A battery stores what you don't use there and then, so you can draw on it in the evening instead of buying it back from the grid. It doesn't generate anything itself and it doesn't change how many panels you need. It changes when you use the electricity you've already made. Our how it works page covers the survey-to-handover process if a battery is new ground for you.

Who a battery suits

You're out at work during the day. Your panels are generating from roughly mid-morning to mid-afternoon, and you get home after that's dropped off. Without a battery, most of that solar goes to the grid for an export payment rather than into your own evening use. With one, it's there when you walk in and put the oven on.

You charge an EV. Overnight charging on a cheap tariff is one option. Charging from stored daytime solar, or topping the battery up overnight on a cheap tariff and using it through the next day, is another. Either way, a battery gives you a second place to put cheap electricity rather than relying on the grid at the exact moment you need it.

Heat pumps fit a similar pattern. They draw steadily through the day and often run hardest in the morning and evening, outside the hours your panels are working hardest, so a battery smooths that out in much the same way it does for an EV.

If you're on a time-of-use tariff, or thinking about one, a battery earns its keep a third way. Tariffs that charge less overnight and more at peak times (Economy 7-style tariffs and the newer smart tariffs from several suppliers) reward anyone who can shift their usage into the cheap window, or avoid the expensive one. A battery that's topped up at the cheap rate overnight, or from solar in the day, lets you avoid drawing from the grid at the priciest time of day.

Power cuts worry you. A standard battery set-up isn't whole-home backup. It won't silently keep everything running the way a generator would. But paired with the right inverter set-up it can keep key circuits going, and whole-home backup is something we specify and price after a survey, once we know what you actually want covered.

Who it doesn't suit as well

You're home all day and use power as you make it. If you're retired, work from home, or someone's in most of the day, a lot of your solar is already going straight into the washing machine, the kettle and the lights rather than sitting unused. A battery has less spare daytime solar to capture.

Your roof or budget only stretches to a smaller array. A 6 or 8-panel system doesn't generate much surplus to store once the house has drawn what it needs. A battery on a small system spends more of its time half-empty.

You just want the lowest possible upfront cost. A battery is an extra piece of kit on top of solar, not a free add-on. If the budget is tight, it's a perfectly reasonable second step, added later, rather than something to force into the first install.

How long do solar batteries last, and what's covered

Pro-Fit's battery brands, Fox ESS, Sigenergy, Sunsynk and Powervault, carry a manufacturer warranty of up to 12 years, confirmed in your handover pack once the brand and model for your install are fixed. The hybrid inverter that comes with every Pro-Fit solar install is battery-ready from day one, whether or not you take a battery now, and its own warranty is set out on your written quote. Workmanship on the installation itself carries a 2-year Pro-Fit warranty, and the panels carry a manufacturer warranty of up to 25 years.

A battery's working life in practice comes down to how many times it's charged and discharged, not just the calendar. A battery that's cycled hard every single day will reach the end of its useful capacity sooner than one that's topped up a few times a week. Twelve years of manufacturer cover is the benchmark to ask about, whichever brand you're quoted.

What size battery do you need?

Panel count, roof orientation, how much of the day you're home, and whether you're charging an EV all feed into the right battery size for your house. A battery that's too small empties by 8pm and leaves you back on grid power for the rest of the evening. One that's too large sits part-full most nights and you've paid for capacity you rarely use. We've written a separate guide to sizing a battery to your household at /advice/what-size-solar-battery: work through that once you've decided a battery's worth having at all.

What a battery adds to the price

Pro-Fit's guide prices, fixed in writing after a free survey, show the gap plainly:

The jump from solar only to a 6kWh battery runs from £1,700 to £1,800 depending on the array size. Stepping up again to a 12kWh battery adds a further £1,600 to £1,700. Every price includes the hybrid inverter, scaffolding (arranged and paid for by Pro-Fit), bird protection, the monitoring app, grid paperwork and help registering for export payments, whether or not a battery's included. See the full pricing table for every panel and battery combination, and bring your bills to the survey so we can talk through sizing against what your household actually uses.

Fitting a battery later

A Pro-Fit hybrid inverter is battery-ready from day one, so if you go solar-only now, adding a battery later doesn't mean replacing the inverter. It's a case of booking the battery in as its own job. If you think you'll want one within a year or two, it's worth saying so at the survey even if you don't order one now, so the inverter and any cabling are set up with that in mind.