In an era of rising electricity costs and growing environmental consciousness, many UK homeowners are turning to solar batteries. The concept of energy storage isn’t new, but recent advancements in technology have made it more accessible and efficient for residential use.
The term ‘solar battery’ refers to a battery energy storage system that’s used in combination with solar panels – solar panels generate the electricity and a solar battery stores what would otherwise be sent to the national grid.
When paired with solar panels or used on their own, solar batteries offer cost savings by storing cheaper energy to use during peak hours or when the sun isn’t shining.
This guide aims to provide a comprehensive overview of solar battery costs, benefits and considerations for UK homeowners.
Average cost of solar batteries in the UK
The cost of solar batteries in the UK can vary widely, with most ranging from £3,000-£8,000. This price range includes the battery itself and installation costs.
Another way to look at solar battery costs is to calculate the price per kilowatt hour (kWh) of storage. According to Heatable, your standard pricing here can range from £265 to £415 per kWh, including installation costs.
To give you more of an idea, a standard 5kWh storage battery suitable for a three-bedroom house will cost around £4,500 on average. However, larger systems with higher capacity, such as Tesla’s 13.5kWh Powerwall 3, can easily reach the upper end of the price range when installation is factored in.
If you buy the solar battery separately, you’ll have to factor in installation costs by a qualified electrician – MCS certification isn’t a requirement for battery installation, as it is for solar panel installation.
You can expect to pay around £300 to £500 per person per day in labour costs. As battery storage installation is relatively straightforward compared to solar panels, it should only take one person no more than one day.
Factors affecting solar battery costs
The exact cost of a solar battery will depend on several factors. Let’s take a look at some of the more important ones.
- Battery capacity and power output – Capacity (kWh) determines how much energy the battery can store. Power output (kW) indicates how much energy the battery can deliver at once. Higher capacity and output generally mean higher costs. For example, a 5kWh battery might be sufficient for a small household with minimal energy needs, whilst a larger family home might require a 13.5kWh system or even multiple batteries. The power output is crucial for running multiple appliances at the same time or powering high-demand devices, such as electric heating.
- Depth of Discharge (DoD) and efficiency – DoD refers to how much of the battery’s capacity can be used without damaging it. Higher DoD means more usable capacity. Most modern lithium-ion batteries offer 100% DoD, meaning you can use their entire capacity. Efficiency, sometimes called ’round trip efficiency’, indicates how much energy can be used compared to what’s put in. For example, a battery with 90% round trip efficiency will deliver 9kWh of usable energy for every 10kWh put into it. Higher efficiency means less energy waste and potentially more savings.
- Battery chemistry – The most common types of solar batteries are lithium-ion. This includes lithium iron phosphate (LFP) and nickel manganese cobalt (NMC). LFP batteries are known for safety and longevity, whilst NMC batteries offer higher energy density, which can be beneficial if you have limited installation space.
- Scalability – Some systems allow for adding more battery modules later. This is good if you anticipate increased energy needs in the future, such as getting an electric vehicle or switching to electric heating. For example, the Tesla Powerwall 2 can be scaled up to 10 units, whilst the SonnenBatterie 10 can be expanded up to a massive 198kWh capacity. Scalable systems often come with a slight price premium.
- Brand reputation and warranty – Well-known brands come with higher prices but may offer better reliability and longer warranties. Look for warranties of 10 years or more. Some manufacturers, like Enphase, offer warranties up to 15 years, which can provide additional peace of mind. It’s also worth considering the financial stability of the manufacturer, as you want the company to be around to honour the warranty if needed.
- Installation complexity – Battery storage should be a fairly simple installation for a qualified expert. However, if upgrades need to be made, for example to your existing electrical panel, costs could increase by several hundred to a thousand pounds.
Comparison of popular battery storage systems
Here’s an overview of the costs for some of the best battery storage systems available in the UK.
| Battery model | Capacity | Warranty | Price |
| Tesla Powerwall | 13.5 kWh | 10 years | From £6,000 |
| Powervault P4 | 8 kWh | 10 years | From £3,000 |
| Enphase IQ 5P | 5 kWh | 15 years | From £4,700 |
| GivEnergy All in One | 13.5 kWh | 12 years | From £6,900 (installed) |
| Huawei Luna | 5 kWh | 10 years | From £3,000 |
| SonnenBatterie 10 | 5.5 kWh | 10 years | From £4,500 |
| LG Chem RESU | 9.6 kWh | 10 years | From £5,000 |
How battery storage can save you money
There are tonnes of benefits to solar battery storage and a number of ways they can help you save money on your energy bills. If you have solar panels, a battery allows you to maximise the use of your solar energy by storing excess power produced during the day for use at night or on cloudy days. This increases your self-consumption of solar energy, reducing your reliance on grid electricity and lowering your bills.
Another significant benefit comes from reducing your reliance on the grid during the most popular times. By using stored energy during times when electricity rates are highest, you can substantially cut your energy costs. Using the same logic, you can take full advantage of time-of-use tariffs to charge your battery when electricity is cheapest and then use it when prices are at the highest.
If you have plenty of excess energy, it’s also possible for you to earn money from your battery by selling electricity back to the grid during peak hours, adding another potential stream of savings to your investment in battery storage.
Potential savings and return on investment
By now you should be aware that you can save money on your energy bills with battery storage. But just how much can you save?
On average, combining solar panels with battery storage can reduce your annual electricity bill by 70-80%. Without a battery, these savings are typically around 50%. The precise amount you can save with a solar battery system depends on several factors, such as size and efficiency of your solar panel system (if you have one), your household’s energy consumption patterns, your electricity tariff and the capacity and efficiency of your battery system.
Let’s take a look at some scenarios:
- Small home with battery storage but without solar panels
- Annual energy consumption: 1,800 kWh/year
- Battery size: 5 kWh
- Estimated annual savings: £280
- This scenario assumes the homeowner charges the battery during off-peak hours and uses the stored energy during peak times.
- Medium-sized home with battery storage and solar panels
- Annual energy consumption: 2,700 kWh/year
- Solar panel capacity: 3.5 kW
- Battery size: 8 kWh
- Estimated annual savings: £600
- In this case, the battery allows the home to use more of their solar-generated electricity, reducing grid reliance.
- Large home with battery storage and solar panels
- Annual energy consumption: 4,100 kWh/year
- Solar panel capacity: 5 kW
- Battery size: 12 kWh
- Estimated annual savings: £900
- This scenario maximises self-consumption of solar energy and minimises grid electricity use during peak hours.
The payback period for a solar battery system typically ranges from 8 to 12 years, depending on the initial cost, energy savings and any income from exporting excess energy to the grid. However, with rising electricity prices and potential future incentives, this payback period could shorten. You can learn more about battery storage energy savings here.
As of February 2024, battery storage systems are VAT-free in the UK, offering a 20% saving on the purchase price. This significant discount makes battery storage more accessible to many homeowners.
It’s worth noting that alongside the financial savings, many homeowners also value the increased energy independence and reduced carbon footprint that come with battery storage systems too.
Choosing the right battery storage system for your home
Getting the right size battery storage system for your home is essential. Oversizing or undersizing your system will lead to inefficiencies when it comes to usage and savings.
Of course, you’ll want to use an expert and qualified installer to help you determine the right size battery for your home. You can use our guide to calculate battery storage size to give you a bit more of an idea.
Here are a few tips on selecting the most suitable battery system:
- Assess your energy consumption – Review your electricity bills to understand your usage patterns. Look at both your total consumption and how it’s distributed throughout the day. If you already have solar panels, look at how much is being exported on a regular basis. This gives you a strong idea of how much of your solar energy you could be sending to battery storage.
- Consider future needs – If you’re planning to get an electric vehicle or increase your energy usage, choose a scalable system. It’s often more cost-effective to install a larger system initially than to upgrade later.
- Check compatibility – If you have solar panels, make sure the battery system is compatible with your existing setup. Some batteries work better with certain inverter types or solar panel configurations.
- Evaluate additional features – Some battery systems offer advanced features like integrations with smart home systems and mobile apps for monitoring and control. Smarter systems are often more efficient. Determine which features are important to you.
Tips for maximising savings
To get the most out of your battery storage system, you’ll want to select the best tariff. A version of a time-of-use tariff will allow you to take advantage of off-peak charging, enabling you to charge your battery when electricity is cheapest and use it when rates are highest. Octopus Energy have some of the best battery storage tariffs. It’s particularly beneficial to use your stored energy during popular times, usually in the early evening when people return from work and energy demand is high.
Regular maintenance of your system is crucial for optimal performance. This includes keeping solar panels clean (if you have them) and ensuring all components of your battery system are functioning correctly. Many battery systems come with apps that allow you to monitor your energy usage in real-time. Take advantage of these tools to track your energy production, storage and consumption, adjusting your habits to maximise self-consumption of stored energy.
Consider your appliance usage carefully. Try to run high-energy appliances like washing machines or dishwashers during times when your solar panels are producing energy or when off-peak rates apply. Investing in energy-efficient appliances can also help – the less energy your appliances consume, the longer your stored energy will last.
Heating and cooling are often the biggest energy consumers in a home. Optimise these systems by using programmable thermostats and ensuring good insulation to help reduce the load on your battery system. Remember that your energy production and consumption patterns will likely change with the seasons, so be prepared to adjust your usage habits accordingly to make the most of your system year-round.
Limitations of battery storage
Limitations of battery storage
Although there are many reasons to get battery storage, it’s important to understand the potential limitations too.
One of the most common questions we get is can battery storage power a house? Most standard residential batteries can’t power an entire home for extended periods, especially if you have high-energy appliances.
For example, a typical 13.5kWh battery might power an average UK home for about 24 hours or slightly longer, but this could be much less if you’re running energy-intensive appliances. Devices like electric heaters, electric showers, tumble dryers and electric vehicle chargers can quickly drain a battery.
Seasonal variations can also affect battery performance. In the UK, solar panels produce significantly less energy during winter months due to shorter days and less intense sunlight. This means you might rely more on grid electricity to charge your battery during these periods, potentially reducing the system’s effectiveness.
The initial cost of battery storage systems can be significant, which might be a barrier for some homeowners. However, it’s important to consider this as a long-term investment, weighing the upfront costs against potential long-term savings and benefits.
Whilst modern batteries are designed to last 10-15 years, they will gradually lose capacity over time. Most manufacturers guarantee that the battery will retain at least 60-70% of its original capacity by the end of the warranty period. This gradual degradation is a normal part of battery life but should be factored into long-term planning.
Wrap up on solar battery costs
Investing in a solar battery system can significantly reduce your reliance on the grid, lower your energy bills and contribute to a more sustainable future.
Although the upfront costs are fairly high, the long-term savings and environmental benefits make it an attractive option for many UK homeowners. There are also many ways to finance battery storage, including green loans, mortgages and 0% finance agreements.
However, it’s crucial to approach this investment with a clear understanding of your energy needs and usage patterns. The right system for one home might not be the right system for you. The most important factors are your current energy generation and use, plus future energy needs. Remember to thoroughly research your options and consult with professionals before making a decision.
