10kWh Solar Battery: Price & What It Runs
The UK’s most popular home battery size — enough for a full evening and overnight. Here’s what a 10kWh battery costs in 2026, exactly what it runs, and whether it beats a 5kWh for your home.
The short answer
A 10kWh solar battery costs £4,500–£7,000 installed in 2026, and it’s the UK’s most popular home size for a reason: 10kWh roughly matches a typical household’s evening-and-overnight demand, so you can bank the day’s solar surplus and run the house after dark instead of buying at peak rates.
In real terms, 10kWh covers a full evening plus overnight for an average home — think ~130 hours of fridge, 10–14 hours of TV, several appliance cycles, or a useful EV top-up. On hardware maths alone a battery rarely fully pays back, but paired with a smart tariff and a home that cycles it daily, a 10kWh makes strong sense — especially for medium-to-large or EV households. Smaller homes should weigh a 5kWh instead.
What this guide covers
The 10kWh battery is the default choice for a lot of UK homes — big enough to run a household through the evening and overnight, without the cost or bulk of the largest systems. This guide gives you the honest 2026 prices, shows you exactly what 10kWh runs in everyday terms, and settles the question most people are really asking: is 10kWh the right size, or would 5kWh do? Let’s start with cost.
How much does a 10kWh solar battery cost in 2026?
| 10kWh battery type | Typical installed price | Notes |
|---|---|---|
| Value brands (Fox ESS, Pylontech) | £4,500–£5,500 | Strong value, LFP chemistry |
| Mid-range (GivEnergy*, Growatt, SolaX) | £5,000–£6,000 | Popular all-rounders |
| Premium (Tesla Powerwall) | £6,000–£7,000+ | Powerwall is ~13.5kWh, premium features |
| Retrofit to existing solar | +£500–£1,500 | If a hybrid/AC-coupled inverter is needed |
So £4,500–£7,000 installed covers most 10kWh options in 2026, with the spread driven by brand, chemistry and whether it’s fitted with a new system or retrofitted. Fitting a battery at the same time as your panels is usually cheaper than adding it later, since the inverter and labour are shared. *Note on GivEnergy: following its 2026 administration, be cautious about warranty security on discounted stock — a real consideration on a £5,000+ purchase. For the smaller-capacity option, our 5kWh battery guide covers pricing at that size.
kW vs kWh — the bit that trips everyone up
“10kW” battery usually means 10kWh — here’s the difference
People search “10kw solar battery,” but batteries are really rated in kWh (kilowatt-hours), not kW. The two mean different things: kWh is capacity — the size of the tank, how much energy it stores (a 10kWh battery holds 10 units of electricity). kW is power — how fast it can pour that energy out at once (how many appliances it can run simultaneously). So a “10kW battery” almost always means a 10kWh capacity battery, which might have, say, a 5kW power output. When comparing, check both: capacity (kWh) decides how long it lasts, power (kW) decides what it can run at once. Most 10kWh home batteries output 3.6–5kW, plenty for a normal household. Same distinction we explain in the 5kWh guide — it’s the single most common battery misunderstanding.
What can a 10kWh solar battery actually run?
Capacity means little in the abstract, so here’s what 10kWh of stored electricity delivers in everyday terms (a full charge, appliances used one area at a time):
| Appliance | Typical use | Roughly how long on 10kWh |
|---|---|---|
| Fridge-freezer | ~0.075kW avg | ~130 hours |
| LED TV | ~0.08kW | ~10–14 hours |
| Dishwasher | ~1.2kWh/cycle | ~8 cycles |
| Washing machine | ~1kWh/cycle | ~10 cycles |
| Electric oven | ~2kW | ~5 hours |
| EV charge | 7kW charger | ~30–40 miles of range |
| Whole average home (evening+night) | ~8–10kWh/day off-solar | A full evening + overnight |
The headline that matters: for an average home using 8–10kWh a day outside solar hours, a 10kWh battery covers most of your off-solar usage — you fill it from the roof (or cheap off-peak power) by day, and run the house on it through the evening and night. That’s the whole appeal: shifting your consumption off the expensive grid and onto stored cheap or free energy. A larger home, or one with an EV or heat pump, uses more and may want extra capacity; a smaller home may not fully cycle 10kWh — which is the crux of the sizing question.
10kWh vs 5kWh: which size do you need?
| 5kWh | 10kWh | |
|---|---|---|
| Typical installed cost | £2,500–£4,500 | £4,500–£7,000 |
| Covers | A typical evening | Evening + overnight |
| Best for usage of | Under ~3,500kWh/yr | ~3,500–6,000kWh/yr |
| Suits | Smaller homes, lower usage, budget | Medium-large homes, EV/heat pump |
| Solar surplus needed to fill it | Modest | A 4kW+ system helps |
The honest rule: size the battery to your off-solar usage and your solar surplus, not to a round number. A 5kWh covers a typical evening and suits smaller or lower-usage homes and tighter budgets. A 10kWh stores a full evening plus overnight and suits medium-to-large homes, higher usage, and EV or heat-pump households — but only pays its way if you actually cycle it most days. Buy 10kWh for a small, low-usage home and you’re paying for capacity that sits half-empty; the surplus to fill it also matters, so a 10kWh pairs best with a 5kW or larger array. If you’re weighing system and battery together, our battery guide and sizes guide join the dots.
Is a 10kWh battery worth it?
Our honest position, unchanged: on hardware cost alone, a battery rarely fully pays for itself before it needs replacing. A 10kWh unit saving, say, £400–£700 a year against a £5,000–£7,000 cost implies a payback close to or beyond its warranty — so if pure ROI is your only test, go in clear-eyed.
But three things change the picture for a 10kWh specifically. First, a smart tariff: charging the battery on cheap off-peak power (some rates a fraction of peak) and using it at peak can add meaningful savings beyond just storing solar — often the difference-maker. Second, a home that cycles it fully most days (medium-to-large usage) extracts far more value than one that half-fills it. Third, the non-financial value — backup during cuts, insulation from rising prices, energy independence — which many owners weigh alongside the pure maths. For a higher-usage home on a good tariff, a 10kWh battery is one of the more defensible battery buys; for a small, low-usage home, a 5kWh (or no battery yet) is often the smarter call.
Brands and what to look for
At 10kWh you’ll be choosing between names like Fox ESS (strong value, modular), Pylontech, GivEnergy (mind the administration caveat above), SolaX, Growatt and the premium Tesla Powerwall (~13.5kWh). Beyond price, check:
- Chemistry: modern LFP (lithium iron phosphate) is the safe, long-life standard — look for it.
- Usable vs nominal capacity: “10kWh” may have ~9–9.5kWh usable (depth-of-discharge). Compare usable figures.
- Power output (kW): 3.6–5kW suits most homes; higher if you run big loads together.
- Warranty: typically 10 years / thousands of cycles — and check the company is sound enough to honour it (the GivEnergy lesson).
- Modularity: some ranges (like Fox ESS) let you stack more capacity later as usage grows.
10kWh battery: pros & cons
✓ Pros
- Covers a full evening + overnight for most homes
- The UK’s most popular, well-supported size
- Strong with a smart tariff (off-peak charging)
- Backup power & price-rise protection
- Good fit for medium-large & EV/heat-pump homes
- Wide brand choice at competitive prices
✗ Cons
- £4,500–£7,000 — rarely pays back on hardware alone
- Oversized for small/low-usage homes
- Needs a decent solar surplus (or off-peak) to fill
- Only worth it if cycled most days
- Check warranty security (administration risk)
Frequently asked questions
How much does a 10kWh solar battery cost?
£4,500–£7,000 installed in 2026, depending on brand and whether it’s fitted with new solar or retrofitted. Value brands (Fox ESS, Pylontech) sit lower; premium (Tesla Powerwall, ~13.5kWh) higher. Retrofitting can add £500–£1,500 if a hybrid/AC-coupled inverter is needed.
What can it run?
A full evening plus overnight for an average home — roughly 130 hours of fridge, 10–14 hours of TV, several appliance cycles, or ~30–40 miles of EV charge. For a home using 8–10kWh a day off-solar, it covers most of that.
Is 10kWh big enough for a house?
For most UK homes, yes — it’s the most popular size because it matches a typical evening-and-overnight demand. Larger, EV or heat-pump homes may want 13–15kWh; smaller ones a 5kWh.
10kWh or 5kWh?
Match it to your off-solar usage and solar surplus. 5kWh for smaller/lower-usage homes and tighter budgets; 10kWh for medium-large, higher-usage or EV/heat-pump homes. Don’t buy capacity you won’t cycle.
Is a 10kWh battery worth it?
Rarely on hardware maths alone, honestly — but with a smart tariff, daily full cycling and the value of backup and price protection, it’s one of the more defensible battery buys for a medium-to-large home. Small homes: consider 5kWh or waiting.
How long does it last?
Daily: an evening plus overnight for an average home. Lifespan: modern LFP batteries are typically warrantied 10 years / thousands of cycles, often keeping 60–80% capacity at end of warranty — so 10–15 years of useful life with daily cycling.
The default size — for the right-sized home
The bottom line: 10kWh is the right default for most medium-to-large UK homes — it covers a full evening and overnight, and with a smart tariff and daily cycling it’s a defensible buy. Just make sure your usage and solar surplus justify it; if they don’t, 5kWh saves you money.
See my savings →The verdict
The 10kWh battery earns its “default size” status: for most medium-to-large UK homes it stores a full evening plus overnight, letting you run the house on banked solar or cheap off-peak power instead of buying at peak. Paired with a smart tariff and a home that cycles it daily, it’s among the more sensible battery purchases — and the backup and price-protection value is real on top.
The honest caveat holds: on hardware cost alone it rarely fully pays back, and it’s oversized for a small, low-usage home. So the decision comes down to your usage, your solar surplus and your tariff — get those checked against a 10kWh and a 5kWh before committing. A free savings check models exactly that for your home.
Important
Going Solar UK is an introduction service, not an installer. We don’t design, supply, or fit battery systems ourselves. Prices, capacities, runtimes and savings here are indicative 2026 figures and vary by brand, home, usage, solar system and tariff — appliance runtimes are illustrative estimates based on typical power ratings and real figures differ. Always get a survey and quotes from MCS-certified installers before relying on them.
We may receive a commission when we introduce you to an installer, at no cost to you. Any contract for work is directly between you and the installer.