TL;DR
Three options: battery-only on a cheap-rate tariff, solar-only, or solar + battery. Solar + battery wins for most UK homes — lowest bills, strongest 10-year return.
Battery-only makes sense for flats, listed buildings, heavily shaded roofs, or north-only roofs. Solar-only still works for work-from-home households on a 15p SEG tariff. Everyone else should fit both.
You’ve got three ways to cut your electricity bill with home energy kit in 2026. You can fit solar panels and nothing else. You can fit a battery on its own and fill it with cheap overnight units. Or you can do both. Which wins depends on your roof, your usage, and how much you care about 10-year versus 25-year economics.
Most UK homes should fit solar + battery. We’ll say it plainly: battery-only only makes sense when solar is genuinely impossible. Solar-only is a false economy for most households past 2026. The rest of this page shows you exactly where the exceptions live and how the numbers stack up on our free savings calculator.
The three options in 60 seconds
- Battery-only: charge a 5–13 kWh home battery off-peak at 7–8p/kWh on a tariff like Octopus Go, discharge at 27–28p peak. Upfront £4,000–£7,000. No panels needed. No generation, so no SEG income.
- Solar-only: a 3–5 kWp array and inverter, no battery. Self-consume 25–45% of what you generate; export the rest on the Smart Export Guarantee at 5–15p/kWh. Upfront £5,000–£8,000.
- Solar + battery: panels plus a 5–10 kWh LFP battery and hybrid inverter. Self-consumption jumps from 45% to 75%. Upfront £9,000–£14,000. Bills drop 60–80%.
Battery-only on cheap-rate tariffs
The pitch: skip the panels, fit a battery, and use a time-of-use tariff to buy electricity when it’s cheap and burn it when it’s dear. It’s the setup that gets flats and listed buildings in the game. Done right, it clips £500–£800 a year off a typical bill.
How the arbitrage works
Octopus Go sits at 7.5p/kWh between 00:30 and 05:30 and roughly 28p the rest of the day (Q1 2026 rates). You charge the battery full overnight, then discharge through the evening peak. A 10 kWh battery cycled daily moves roughly 9 kWh at a 20p/kWh spread — that’s £1.80/day, or £650/year. Intelligent Go and Cosy (also Octopus) work similarly, with slightly different windows. Ofgem’s smart-meter guidance explains the SMETS2 meter you’ll need.
Who it suits
Four clear groups. Flat-owners with no roof rights. Listed-building owners where Historic England or the local conservation officer has blocked visible panels. Homes with heavy shading from tall oaks, neighbouring extensions, or chimneys that wreck solar yield. And renters with written landlord consent — battery-only is reversible in a way roof-mounted solar isn’t.
Payback and limitations
Payback lands at 8–11 years on current spreads. No generation means no SEG income, no hedge against long-term grid price rises, and no 25-year free-electricity tail. Here’s the honest downside: battery-only depends on the off-peak/peak spread staying wide. If Ofgem tightens TOU tariff rules or wind generation shifts the wholesale curve, your payback stretches. We’d still recommend it for the four groups above — just be aware you’re exposed to tariff regulation in a way a solar owner isn’t. Read more on our battery storage page.
Solar only (no battery)
Solar-only was the default in 2015. Ten years on, it’s a narrower fit. A 4 kWp array still generates ~3,600 kWh a year, but without a battery most UK homes self-consume only 25–45% of that. The rest exports at 5–15p/kWh while you buy back at 28p. The maths still works for specific households — it just isn’t the obvious choice any more.
When this still makes sense
Work-from-home households self-consume more of their midday generation naturally — dishwashers, laundry, the kettle, an immersion heater dumping surplus into a hot water tank. Tight budgets: solar-only at £6,000 fitted is cheaper than adding a battery today. Small installs where a 3 kWp array generates close to what the house uses at midday. In each case, payback sits around 8–11 years and panels keep producing for 25+ years after that.
Export-heavy households on good SEG tariffs
Octopus Outgoing Fixed pays 15p/kWh as of Q1 2026 — the highest rate on any major export tariff. If you’re out of the house most days and can’t time-shift load to midday, you’ll export 60–70% of generation. On 15p SEG, that’s genuinely useful income. A 5 kWp array exporting 3,500 kWh earns ~£525/year before you’ve offset a single unit of import. More on how the scheme works on our Smart Export Guarantee guide.
Solar + battery (the default recommendation)
For any UK home with a viable roof, solar + battery is the setup we fit 85% of the time. You get the generation, you get the storage, and you keep the hedge against 25 years of energy-price inflation. The battery is where the profit lives.
Self-consumption uplift (45% → 75%)
No battery? You’re at 25–45% self-consumption for an average UK family. Fit a 5–10 kWh LFP battery (GivEnergy, Tesla Powerwall 3, Pylontech, Sigenergy) and you’re at 70–80%. Every extra kWh you self-consume is worth 28p instead of the 5–15p export rate. On a typical 4 kWp array that’s an extra £350–£500/year. Chemistry matters: LFP has won in 2025 for safety and cycle life. We’ve stopped fitting NMC chemistries in residential retrofits.
Real ROI over 10 years
A £10,400 system saving £1,150/year in bills plus £150 in SEG income returns 12.5% in year one and rises with every Ofgem price-cap bump. Ten-year profit: roughly £4,500–£8,500 after you’ve paid off the system around year seven. Twenty-five-year profit lands around £24,000 assuming 4% annual energy inflation (roughly Bank of England CPI forecasts plus the long-run electricity premium). That’s what battery-only can’t match — the free-electricity tail after payback.
Side-by-side comparison
Typical 3-bed UK semi using 4,000 kWh/year at 27p import and 15p export (Octopus Outgoing Fixed, Q1 2026). 0% VAT applied under HMRC’s VAT Notice 708/6. Battery-only assumes Octopus Go at 7.5p/28p.
| System | Upfront cost | Annual savings | Payback | 10-year profit | Suits |
|---|---|---|---|---|---|
| Battery-only (tariff arbitrage) | £4,000–£7,000 | £450–£750 | 8–11 years | £0–£2,500 | Flats, listed buildings, heavily-shaded roofs, renters with consent |
| Solar only (no battery) | £5,000–£8,000 | £550–£850 | 8–11 years | £1,500–£3,500 | Work-from-home, daytime-heavy usage, tight budget, export-heavy households on 15p SEG |
| Solar + battery | £9,000–£14,000 | £1,100–£1,550 | 6–8 years | £4,000–£8,500 | Most UK homes — especially EV, heat pump, or family households |
Last reviewed: April 2026. Figures reflect typical installs on our books; your numbers will differ by postcode, roof orientation and usage pattern.
Decision framework by household type
Four household profiles cover most of what we see at survey. Find yours, read the recommendation, then pressure-test it on the calculator.
Small daytime usage (couple out 9–5)
Two adults, no kids, both in the office. Usage 2,500–3,500 kWh/year, concentrated in evenings. Solar-only is a poor fit — you’ll export 70% at 5–15p while paying 28p to import at 6pm. Either fit a battery with the solar (preferred) or skip the panels and go battery-only. Both options target the same evening-peak problem; battery-only is cheaper upfront and the right call when roof space is tight.
EV owner
Solar + battery dominates. An EV pulls 2,500–4,000 kWh/year by itself. Charge off-peak on Intelligent Go at 7p overnight, top up with solar surplus during the day, run the battery through the evening. Households pairing solar + battery + EV typically hit 80–90% energy independence and sub-6-year payback. Check the Intelligent Go tariff terms before you sign.
Heat pump home
Big solar + big battery. A heat pump takes a typical 3-bed from 3,500 kWh/year to 7,000–8,000 kWh/year. More import to offset = more generation to justify. Fit 5–6 kWp of panels and a 10–13.5 kWh battery. The numbers are larger but the percentages stay the same: 60–80% bill reduction, 6–8 year payback. Check our sizing guide before committing.
Work-from-home
Solar + battery is still the strongest play, but solar-only runs it close. You’re home at midday to self-consume generation directly — laptop, router, kettle, dishwasher. Self-consumption hits 45–60% without a battery. If cash is tight, install panels now and retrofit a battery in 2–3 years onto a hybrid-ready inverter. The full case for solar panels is laid out on our worth-it guide.
Calculate your scenario
Run your actual roof and actual usage against the three options. The calculator returns a payback period, annual savings, and 25-year profit for each. Takes about 60 seconds.
Estimated annual savings
£1,180/yr
That's £98/mo back in your pocket
Includes ~£87/yr export income from surplus sold to the grid
£11k
System cost
0% VAT
~8yrs
Payback
£32k
25-yr profit
Your 25-Year Savings Journey
See when your investment pays for itself
Estimate based on UK average solar yield and current electricity costs. Actual savings depend on roof orientation, shading, and usage. Book a free survey for a precise quote.
Frequently asked questions
Can I add solar to a battery-only system later?
Yes, if you bought a hybrid inverter. If you fitted an AC-coupled battery (plug-and-play type like a Tesla Powerwall 3 or GivEnergy All-in-One), adding solar later means either a second inverter or swapping units. Ask your installer for a hybrid inverter now if solar is on the 3–5 year plan — a £300 upgrade today saves £1,500 in rework later.
Is battery-only cheaper than solar-only?
Usually yes on upfront cost (£4k–£7k vs £5k–£8k), but it saves less per year. Battery-only relies on the gap between off-peak and peak rates staying wide. Solar-only keeps generating free electricity for 25+ years regardless of what tariffs do. Over a 15-year horizon, solar-only tends to edge ahead.
Do I need a smart meter for a battery-only system?
Yes — a SMETS2 smart meter is required for any time-of-use tariff like Octopus Go or Intelligent Go. Without one, you can't access the 7.5p off-peak rate that makes battery-only viable. Your supplier fits them for free; book it before your battery install.
What happens in a power cut?
Most standard installs stay off during a grid outage for safety reasons (engineers working on lines need to know nothing's back-feeding). If backup matters, ask for a battery with an EPS (Emergency Power Supply) port or whole-home backup — Tesla Powerwall 3 and GivEnergy All-in-One both offer it. Adds £500–£1,500 to the install.
Can I switch from battery-only to solar+battery later?
Yes — if the inverter is hybrid-ready. The panels, DC cabling, and MCS certification are the added work; the battery stays. Retrofitting solar onto an existing hybrid setup typically costs £4,000–£6,000 for a 4 kWp array. You'll also need a DNO G98 or G99 notification filed by your installer.
Do flats qualify for battery-only?
Usually yes, subject to landlord or freeholder consent. Wall-mounted LFP units like the GivEnergy All-in-One take about 0.6 m² of floor space and 120 kg on a load-bearing wall. You'll need a qualified electrician to wire it to your consumer unit and a smart meter on the property. Leaseholders — check your lease for alterations clauses first.
Is battery-only worth it without solar?
It is, if your usage profile is right. A 10 kWh battery charged at 7.5p overnight and discharged at 28p peak saves roughly £1.80/day. That's £650/year on a typical family home with a smart EV charger. The risk: if Ofgem tightens TOU tariff rules or suppliers narrow the spread, your savings shrink. Track Octopus's tariff page quarterly.
What if my roof is north-facing?
North-only roofs produce 30–40% less than south-facing and push solar payback past 14 years. Battery-only is the pragmatic answer here — you skip the panels entirely and just arbitrage cheap overnight units. That's the scenario battery-only was designed for.
Will battery-only still work if off-peak rates go up?
Partly. If the spread between off-peak and peak narrows, your annual saving shrinks proportionally. Octopus Go has held a 20p+ spread since 2020 and the underlying driver — wind-heavy overnight generation with no daytime demand — isn't going away. But we'd flag this as the biggest risk to a battery-only business case.
Still weighing it up?
We’re MCS-certified installers and we’ll quote honestly for all three setups. Every survey includes a written generation estimate (where applicable), a payback projection based on your actual tariff, and a straight answer on which option suits your home. Start with our installation process, or see what UK grants might slice off the bill.
