Are you considering a solar battery storage system for your home? Here we will explore the best options available and what you should avoid.
As the name suggests, solar battery storage, also referred to as an energy storage system allows you to store electricity generated by your solar panels during the sunlight hours.
This makes the electricity readily available for use in the evenings or on dull days, allowing you to become more self-reliant and reduce your reliance on the grid.
But how much do solar battery systems cost? And are they always worth the investment?
In this guide, we’ll answer the most frequently asked questions, as well as average costs you can expect to pay for a new solar battery system.
Solar Battery Storage UK Key Points:
- A solar battery allows you to store the energy generated by your solar panels.
- This means you can benefit from the energy in the evenings and during the night.
- A solar battery can allow you to use around 30% more solar energy annually.
- On average a new solar battery will cost between £3,000 and £9,000 depending on the size, type and brand of the battery.
How Much Do Solar Batteries Cost?
The cost of a solar battery system is dependent on many factors, including the brand of the battery, the batteries chemical composition, storage capacity and it’s life cycle.
On average, a complete solar storage system can cost anywhere between £3,000 to £9,000 depending on the factors mentioned above.
However, for the average sized UK three bedroom home, the average cost of a solar battery is about £4,700.
Like any new technology, solar batteries or home energy batteries are considered expensive and their price will likely come down as they become more commonplace.
Solar Battery Materials
There are two major types of solar batteries being used today, these are:
- Lithium-ion batteries.
- Lead-acid batteries.
Key takeaway: in general, lithium-ion batteries are considered the gold standard for domestic use and the most cost effective.
The lifespan, efficiency and cost of the solar batteries largely depend on the materials being used in them.
For instance, lithium-ion batteries can discharge 70% – 90% of the total storage.
Typically, a higher discharge rate and longer life span will result in higher prices. A lithium-ion battery can cost £3,500 to £6,000 depending on its usable capacity (kWh).
On the other hand, lead-acid batteries can only discharge 50% of the total amount of storage which means that they are available at comparatively cheaper prices.
A lead-acid battery can cost around £2,000 to £4,500 depending on its usable capacity (kWh).
Check our quick help solar energy guides here:
- Are solar panels worth it in the UK?
- Best 4kw solar system with battery set-up
- Can you install solar panels in a conservation area?
- How many solar panels do you need to power a house in the UK?
- Solar panel battery storage system costs
Lifespan of Solar Batteries
How long will a solar battery last?
The lifespan of a battery is a major factor to consider, since the more life cycles it can provide, the longer it can serve you and your home.
For instance, the average lifespan of solar panels is around 25 years.
So it’s equally important to factor this into choosing a battery, as a battery with a limited lifespan may mean replacing your battery several times over the life of your panels, which can add up.
Battery Storage Capacity
There are two types of capacities that determine the effectiveness and cost of solar battery storage systems i.e., storage capacity and usable capacity.
The storage capacity is the total amount of electricity your battery can store while usable capacity means the amount it can use, which is determined by the depth of discharge (DoD).
Your solar battery slowly experiences a decrease in DoD with the number of cycles it goes through. For example, the use of 100 percent of the battery storage in a battery that has 85 percent DoD will shorten its lifespan.
The general rule is that the greater the storage capacity and usable capacity (measured in kilowatt hours), the more the solar battery will cost.
Solar Panel Battery Installation Costs UK
The installation cost depends on the size and type of the battery.
It is typically more financially wise to set up your solar battery system while installing your solar panels.
Best Solar Battery in the UK
A solar battery that gives you more usable capacity, lifespan, DoD, and a longer warranty is going to offer you the best value.
Comparison table showing the costs of different solar batteries in the UK:
| Battery Brand | Usable Capacity (kWh) | Cost | Battery Material | Warranty | Life Cycles | Depth of Discharge (DoD) |
|---|---|---|---|---|---|---|
| Tesla Powerwall | 13.5 kWh | From £5,700 | Lithium-ion | 10 years | Unlimited* | 100% |
| SolaX 3.3 | 3.5 kWh | From £4,010 | Lithium-ion | 10 years | 6,000 | 95% |
| LG Chem RESU 6.5 | 6.5 kWh | From £3,043 | Lithium-ion | 10 years | 6,000 | 90% |
| Powervault 3 | 4 kWh | From £4,470 | Lithium-polymer | 10 years | >6,000 | 100% |
| 8 kWh | From £7,020 | Lithium-polymer | 10 years | >6,000 | 100% |
Tesla Powerwall undoubtedly takes a lead by offering 13.5 kWh usable capacity, 10-year warranty, unlimited life cycles and 100 per cent DoD.
The cost for Tesla is starting from £5,500 and in many cases Tesla also offer installation with their units, which is another major advantage.
The runner-up for the best solar battery according to the features it offers is Powervault3.
It gives a usable capacity of 8 kWh, a 10-year warranty, 100 per cent DoD and more than 6000 life cycles.
However, the cost of Power vault 3 is starting from £7,020 which is considerably more than the Tesla model.
Check our new guide on solar panels sizes if you are curious to know what size panels you will likely require.
How much money will you save with solar panels & battery storage?
A new solar panel system can save you around half of your electricity bill on average and the financial gains to be made are even more impressive with the new Energy Price Cap taking effect.
For example, the average household with a 4.2 kW solar system could save you as much as £514 a year on your energy bills (based on the new October price cap).
If you also use a solar battery, you could save even more, in fact, without one around 50% is returned back to the National Grid.
So by using a solar battery you could save an extra £120 on average or sell the energy back to the grid using the Smart Export Guarantee (SEG).
The SEG allows you sell the energy you generate back to the grid and depending on the supplier you choose you could sell it for as much as 12p for every kilowatt hour (kWh).
Therefore, to conclude you could save as much as £585 a year for the average sized home (that’s the £465 from the energy generation itself and £120 in SEG revenues you’ll generate for the year).
Please note that these figures are just averages and the actual figures may vary.
What Grants & Funding is available for Solar Batteries?
Even though a solar battery storage system may seem like a considerable expense, the good news is that there are some grant and funding opportunities available in the UK, as well as other schemes you can take advantage of, such as the Smart Export Guarantee.
As of 2023, these include the following solar battery grant schemes are available:
Home Energy Scotland 0% Interest Free Loan
Home Energy Scotland Loan is an interest-free loan designed to help finance various energy efficiency initiatives and renewable systems like solar panels and solar batteries.
You can get a loan of up to £6,000 for a solar PV system, and £5,000 for a solar battery storage system.
The repayment period is between 5-10 years, depending on the installation. For specific eligibility criteria, you can visit the Home Energy Scotland website.
Other than that, there are no direct grant or loan offers in the UK but there are ways to save money with the schemes like Smart Export Guarantee (SEG) and VAT reduction.
Smart Export Guarantee (SEG)
As previously mentioned, you can use the Smart Export Guarantee scheme that allows you to earn money for exporting stored electricity you don’t use to the national grid.
Export tariffs depend on the supplier tariff and the area of the country you reside, but the best tariffs can be as high as 15p per kWh, so make sure you shop around.
For reference, this means a typical household based roughly in the middle of the country could make between £80 and £110/year (based on a rate of 3.99p per kWh).
VAT Reduction Scheme
The other scheme which is value added tax (VAT) reduction means that the VAT on certain energy saving materials has been reduced to 0%.
Those eligible for this offer only need to pay 5% VAT on products like solar batteries and solar panels as opposed to the regular 20% VAT.
The scheme is in operation from April 2022 to 2027 and means that vulnerable households will pay less to make upgrades that meet the requirements of the scheme.
Recommended reading:
- Off Grid Solar – is it possible in the UK?
- Solar car charging guide.
- Solar inverters – what are they?
- GivEnergy battery storage system.
- Best 4kW solar battery storage system.
The lifespan is an important factor contributing to the cost of solar battery storage.
A longer lifespan means fewer replacements while a shorter lifespan can add up to future costs.
For example, a lifespan for a solar panel is typically around 25 years which means a battery having a life span of 10 years will need to be replaced once during the lifespan of the solar system.
Meanwhile, a battery with a lifespan of 5 years must be replaced multiple times which adds to the overall cost of the battery during its lifespan.
The average lifespan for lead-acid batteries is 5 to 7.5 years while the average lifespan for lithium-ion batteries is around 11-15 years.
Types of Solar Battery Storage in the UK
There are four main types of solar battery storage systems available in the market to choose from according to space, usage, output, and cost.
These are as follows:
- RV/Marine Solar batteries.
- Flooded type batteries.
- Gel batteries.
- Absorbed Glass matte (AGM) batteries.
1. RV/Marine Solar Batteries
As the name suggests, these batteries are mainly used in RVs and boats.
They have limited capacity and are used as a single source of electricity production.
2. Flooded type Batteries
Flooded type batteries are lead-acid batteries and have a good life span as compared to marine solar batteries.
They emit gas when charged so it’s strongly advisable to install them outdoors or in an area with good ventilation.
3. Gel Solar Batteries
Gel batteries do not emit any kind of gas so are safer to use indoors.
Since the batteries have a more constant temperature indoors, they perform better than the flooded type.
4. Absorbed Glass Matte (AGM) Batteries
AGM has all the benefits of flooded type but of higher quality. They are risk-proof and have high performance.
They are more expensive than other types of batteries, but they maintain voltage better, self-discharge slower and last longer.
Is Solar Battery Storage worth it?
Since a solar battery storage system is a significant financial investment, you are probably wondering if it always makes financial sense to install one?
Typically, the best situation to install one is if you already have solar PV set up as a battery can easily be added to the existing system.
Equally, if you don’t yet have a solar PV array installed, it can make sense to install them both at the same time.
Why is this?
Essentially by installing a battery storage system with your solar PV array, you can make your solar panels much more efficient and save a considerable amount each and every month on your electricity bill.
Even if you don’t have solar panels installed on your roof, you can still take advantage of a battery storage system.
Many people use them to extract electricity from the grid during low peak times, helping you to reduce the amount you spend on electricity for your home.