Why solar panels alone are not enough
Solar panels generate the most electricity during the middle of the day, precisely when most households use the least. If you are at work or out of the house, that surplus energy gets exported to the grid via the Smart Export Guarantee (SEG). While you do receive a small payment for exported electricity, SEG rates typically sit between 3p and 15p per kWh – far below the 24p or more you pay to import electricity in the evening.
This mismatch between generation and consumption means a typical UK home with a 4 kWp solar array only uses around 40–50% of what it produces. The rest is effectively sold cheaply and bought back expensively later in the day.
How home battery storage works with solar
A home battery system sits between your solar inverter (or generation meter) and your consumer unit. During the day, when your panels produce more than your home needs, the surplus charges the battery instead of being exported. In the evening, when your panels stop generating, the battery discharges to power your home before you need to draw from the grid.
Modern systems handle this automatically. Once installed and configured, there is nothing to manage day to day – the battery decides when to charge and discharge based on your generation and usage patterns.
Key components
| Component | Purpose |
|---|---|
| Battery cells | Store electrical energy, typically lithium iron phosphate (LFP) chemistry for safety and longevity |
| Battery inverter | Converts between DC (battery) and AC (household) electricity; may be integrated or separate |
| Battery management system (BMS) | Monitors cell health, temperature, and charge levels to ensure safe operation |
| Energy management software | Controls charge and discharge scheduling based on solar generation, usage, and tariff rates |
What size battery do you need?
The right battery size depends on two factors: how much surplus solar you generate and how much electricity you use in the evening and overnight.
For a typical UK home with a 3–4 kWp solar installation, a battery capacity of 5–10 kWh is usually sufficient. A smaller battery will fill up quickly on sunny days but costs less upfront. A larger battery captures more surplus but may not fully charge during shorter winter days.
A good rule of thumb: match your battery capacity to your daily evening and overnight usage. If your household uses around 8 kWh between 4 pm and 8 am, an 8–10 kWh battery makes sense. Check your smart meter data or energy app for a more precise figure.
Do you actually need solar panels to use a battery?
No. This is one of the most common misconceptions about home battery storage. While pairing a battery with solar panels is the most popular setup, a standalone battery can deliver significant savings on its own.
Standalone batteries charge from the grid during off-peak hours – typically overnight when rates on time-of-use tariffs can drop as low as 7p per kWh – and then discharge during peak hours when electricity costs 30p or more. The difference between off-peak and peak rates is your saving.
At Habo, we supply pre-configured all-in-one home battery systems designed to work with or without solar panels. Our systems use set-and-forget timer scheduling that automatically charges from the cheapest electricity available, whether that comes from your solar panels or from the grid overnight.
How much can you save?
Savings vary depending on your solar array size, battery capacity, energy usage, and electricity tariff. Here are some typical figures for UK households:
| Setup | Estimated annual saving |
|---|---|
| Solar only (no battery) | £300–£500 |
| Solar + battery (5–10 kWh) | £500–£900 |
| Battery only (off-peak charging) | £250–£500 |
| Solar + battery + time-of-use tariff | £700–£1,100 |
The greatest savings come from combining all three: solar generation, battery storage, and a smart time-of-use tariff. This lets you consume your own solar energy, store surplus for the evening, and top up from the grid at the cheapest overnight rate.
Installation and costs
A home battery installation typically takes half a day to a full day, depending on the complexity of your existing electrical setup. The battery unit is usually wall-mounted in a garage, utility room, or on an external wall.
Costs for a home battery system in the UK currently range from around £2,500 to £6,000 for a 5–10 kWh unit, including installation. The good news is that home battery storage currently benefits from 0% VAT in the UK, a relief that runs until March 2027. This brings the effective cost down significantly compared to a few years ago.
Battery lifespan and maintenance
Modern LFP home batteries are designed to last. Most manufacturers warrant their products for 10 years or around 6,000 charge cycles, whichever comes first. With one cycle per day, that equates to over 16 years of use.
In practice, batteries do degrade gradually over time. After 10 years, you can expect a well-maintained system to retain 70–80% of its original capacity. There is no routine maintenance required – home batteries are truly a fit-and-forget technology.
Frequently asked questions
Yes. Most home battery systems can be retrofitted to existing solar panel setups. An AC-coupled battery connects to your household electrical supply rather than directly to the solar inverter, making it compatible with virtually any existing installation.
Some battery systems offer backup functionality, but not all do. Standard grid-tied batteries will shut down during a power cut for safety reasons (to prevent back-feeding the grid). If blackout protection is important to you, look for a system with an Emergency Power Supply (EPS) feature.
Battery prices have fallen significantly over the past five years and are expected to continue declining gradually. However, with the 0% VAT relief in place until March 2027 and electricity prices remaining high, the financial case for installing now is strong. Every month you wait is a month of savings missed.
Ready to start saving?
Join the Habo waitlist for a simple, affordable all-in-one home battery – installed by MCS-certified engineers.
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