How does a home battery work without solar panels?
A standalone home battery connects to your electricity supply and the grid. It charges from the grid during off-peak hours – typically overnight between midnight and 5am – when electricity costs 7–10p per kWh. It then discharges during peak hours – roughly 4pm to 9pm – when electricity costs 22–30p per kWh. The difference between what you paid to charge and what you would have paid at peak rate is your saving.
This process is called load shifting or tariff arbitrage. You are buying the same grid electricity you already use – just buying it at the cheapest possible time and storing it for later.
To make this work, you need two things: a home battery system with an inverter, and a time-of-use energy tariff that offers cheaper electricity during specific hours. Without a time-of-use tariff, there is no price difference to exploit, and a standalone battery will not save you money.
What equipment do you need?
A standalone battery system has three core components. The battery cells store electricity as DC power, typically using lithium iron phosphate (LiFePO4) chemistry. The inverter converts between DC storage and the AC power your home uses. And the energy management system – usually an app or built-in controller – schedules when the battery charges and discharges.
Many modern units are all-in-one systems that combine the battery, inverter, and controller in a single enclosure. These are simpler to install and typically cheaper than buying components separately. At Habo, we supply all-in-one units specifically because they reduce installation complexity and cost for the homeowner.
How much does battery storage cost without solar in the UK?
A standalone home battery system in the UK costs between £4,000 and £8,000 fully installed, depending on capacity and brand. A 10kWh all-in-one unit – suitable for most three-bedroom homes – typically costs £5,000–£6,500 installed. All battery storage installations in the UK currently qualify for 0% VAT, a policy in effect until 31 March 2027.
| Battery capacity | Typical installed cost | Suited for |
|---|---|---|
| 5 kWh | £3,000 – £4,500 | 1–2 bed flat, low usage |
| 10 kWh | £5,000 – £6,500 | 3 bed house, average usage |
| 12–15 kWh | £6,000 – £8,000 | 4+ bed house, high usage or EV |
How much can you save with a battery and no solar?
A UK household using a 10kWh battery on a time-of-use tariff can save approximately £400–£600 per year. The exact saving depends on the tariff spread (the gap between off-peak and peak rates), how much electricity you use during peak hours, and the efficiency of your battery system. Payback on the initial investment is typically 3–5 years.
Example savings calculation
Consider a household on Octopus Go, which charges approximately 7.5p/kWh during off-peak hours (midnight to 5am) and around 24.5p/kWh during peak hours. If you charge a 10kWh battery overnight and discharge 9kWh of usable energy during the day (accounting for ~10% round-trip losses), your daily saving is:
9kWh × (24.5p – 7.5p) = 9 × 17p = £1.53 per day, or approximately £558 per year.
On Octopus Agile, savings are less predictable because rates vary by half-hour. Average annual savings tend to be lower – around £250–£400 – but savvy users with smart scheduling can occasionally benefit from negative pricing periods where you are paid to consume electricity.
When does a standalone battery not save money?
If you are on a flat-rate tariff with no off-peak period, a standalone battery will not reduce your bills. The entire value of a battery without solar comes from the price spread between cheap and expensive electricity. If that spread does not exist on your tariff, neither do the savings.
Which energy tariffs work with battery storage?
Time-of-use tariffs with a clear off-peak period are essential for battery-only systems. The most commonly used tariffs in the UK for battery storage are Octopus Go, Octopus Intelligent Go, Octopus Agile, Economy 7, and Good Energy EV Charge. You need a smart meter to access most of these tariffs.
| Tariff | Off-peak rate (approx.) | Off-peak window | Notes |
|---|---|---|---|
| Octopus Go | 7.5p/kWh | 00:30 – 05:30 | Requires EV or home battery |
| Octopus Intelligent Go | 7.5p/kWh | 23:30 – 05:30 | Longer window, requires compatible device |
| Octopus Agile | Variable | Variable (half-hourly) | Rates can go negative; more complex |
| Economy 7 | ~12p/kWh | 7 hours overnight | Available from most suppliers |
What is G98 and why does it matter?
G98 is a UK grid connection standard. If your battery inverter is rated at 3.68kW or below (single phase), your installer simply notifies the local Distribution Network Operator (DNO). This is a quick, straightforward process. Inverters above 3.68kW require a full G99 application, which involves a longer approval process and may be refused. Most standalone home batteries with inverters under 3.6kW qualify for G98.
At Habo, we specifically select all-in-one battery units with inverters rated below 3.6kW to ensure every installation qualifies for simple G98 notification. This avoids the cost, delays, and uncertainty of a G99 application – which matters if you want your battery installed quickly and without complications.
Can you add solar panels later?
Yes. If your battery system includes a hybrid inverter, adding solar panels later is a relatively simple upgrade. The hybrid inverter already has DC inputs designed for solar panel connection. You would need to install the panels and connect them to the existing inverter – the most expensive component is already in place.
This makes a battery-first approach practical for households who want to start saving immediately but are not ready for the full cost of a solar-plus-battery installation. Starting with a battery on a time-of-use tariff gives you immediate savings, and adding solar later improves the economics further by reducing how much grid electricity you need to buy at all.
What about backup power during outages?
Some – but not all – home batteries can provide backup power during a grid outage. This feature is called Emergency Power Supply (EPS). For EPS to work, the inverter must support it, and an earth rod may need to be installed for safe operation. If backup power matters to you, confirm EPS support before purchasing.
The average UK household experiences approximately 0.4 power outages per year. Backup power alone is unlikely to justify the cost of a battery, but it is a valuable bonus on top of tariff savings – particularly for homes in rural areas or regions with aging grid infrastructure.
Habo's approach: set and forget
Many battery systems rely on cloud-based optimisation platforms that require an internet connection, ongoing subscriptions, or complex configuration to maximise savings. If the cloud service goes down, your battery may stop scheduling intelligently.
At Habo, we take a different approach. Our all-in-one battery units use simple timer-based scheduling configured at installation. You set your off-peak charging window once, and the battery handles the rest. No ongoing cloud dependency, no subscription fees, no app required to keep it working. It charges when electricity is cheap, discharges when it is expensive, and you do not need to think about it again.
We call this set and forget. It is the simplest, most reliable way to save money with a home battery – and it works whether your internet is up or not.
Ready to start saving?
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