Why you should get a home battery, even without solar

What are the benefits of a battery storage at home?

There are four main benefits to a standalone home battery storage:

1. Electricity cost savings and revenues

A home battery system can create energy cost savings or even revenues in three ways:

• Cheaper consumption: It allows homeowners to charge their batteries at times when electricity is cheap and consume the electricity when it would be expensive if procured from the grid.
• Flexibility rewards: Batteries can be used to stabilise an increasingly strained grid, for which grid operators pay a reward.
• Arbitrage: Any electricity that is not consumed can be sold back to the grid at times when prices are high.

The above will be broken down and quantified in more depth in the subsequent section.

2. Environmental benefits

When charging at the off-peak hours in a Standard Economy 7 tariff and discharging during the day, a household consumes electricity with a ~20% lower CO2 footprint (see Figure 1). This is because the UK grid is cleanest when electricity prices are the lowest, which is when home batteries are charged: When renewables such as wind and solar are at the peak of their production, electricity prices tend to be the lowest. Conversely electricity is dirtiest when there is no wind or solar and when so-called “peaker plants”, which are typically natural-gas-fired power plants, need to be turned on.

3. Resilience

During the recent energy crisis, the daily price spread—the difference between the lowest and highest electricity prices in a single day—increased significantly, rising from an average of 4p to 10p per day (see Figure 2). This widening gap made it even more advantageous to purchase electricity during low-cost periods and use stored energy when prices were higher.

While future energy crises are unpredictable, electricity price volatility is expected to increase as the UK transitions to a more decentralised and renewable-based energy system. A home battery provides protection against these fluctuations, allowing homeowners to optimise energy consumption and reduce exposure to rising peak-time electricity costs.

4. Independence

A home battery enhances energy resilience by providing backup power during outages. While power cuts have been relatively rare in the UK in recent decades, the risk is increasing as the energy landscape evolves. The shift from large, centralised fossil-fuel power plants to smaller, decentralised renewable sources introduces greater variability in electricity supply. At the same time, rising demand from home electrification—such as heat pumps and electric vehicles—places additional strain on the grid.

As infrastructure adapts to these changes, balancing supply and demand becomes more complex, heightening the likelihood of power disruptions. A home battery can help mitigate this risk by supplying backup power, typically sustaining a household for 1–2 days off-grid, with the potential for extended use depending on energy consumption.

Home Battery Storage: Cost Savings and Payback Period Explained

A home battery can achieve cost savings by reducing electricity expenses over time. Based on typical UK household energy consumption, the payback period for a standalone battery is approximately 8 years.

For example, a household of four without a heat pump or electric vehicle consumes around 10 kWh of electricity per day. A 10 kWh battery would be a suitable size and is estimated to cost around £4,500, including installation.

Without a battery, this household would spend approximately £2.60 per day on electricity, assuming a standard tariff rate of 26p per kWh. By using a battery to store energy when prices are lower—charging at 11p per kWh—electricity costs could be reduced to £1.10 per day, leading to annual savings of approximately £550.

This results in a payback period of approximately 8.2 years, calculated as £4,500 ÷ £550 per year. This estimate is based solely on savings from time-of-use optimisation, and additional benefits—such as flexibility market rewards and energy trading—can further improve the financial return.

See Figure 3 for a breakdown of these calculations:

Emerging local flexibility markets are expected to further improve the financial viability of home battery storage. UK distribution grid providers have recently expanded these markets, allowing homeowners to earn additional income by supporting grid stability.

Participation typically occurs through intermediaries (like Capture Energy) that aggregate multiple home batteries to meet the scale required for flexibility auctions. A 10 kWh battery could generate approximately £100–£300 per year in flexibility rewards, depending on market conditions. This additional revenue stream can shorten the payback period to around 5 years.

To determine eligibility for flexibility market participation, complete the short survey at the end of this article.

In addition to flexibility market rewards, energy arbitrage can further enhance the financial benefits of home battery storage. Some UK utilities already offer export tariffs exceeding 20p per kWh, allowing homeowners to sell surplus electricity back to the grid at competitive rates.

At present, the most favourable export tariffs typically require a Solar PV system. However, as energy markets evolve, similar opportunities may become available for standalone batteries. If these tariffs expand to include battery-only systems, homeowners could buy electricity when prices are low and resell it at higher rates, maximising cost savings and potential earnings.

Who can get a home battery?

Home battery storage is a flexible solution suitable for a wide range of households. Modern battery systems are modular, allowing for installation both indoors and outdoors to fit different space constraints. For example, a compact 5 kWh battery can easily be placed in a utility cabinet, making it a practical option even for homes without dedicated storage areas. Unlike solar panels, home batteries do not require roof space and can operate independently, providing energy savings and backup power. For more information on how to size a battery for your home, take a look at our recent article on this topic, or answer the short survey below to get a personalised recommendation: