Do I Need a Solar Battery for my Home?

Solar batteries for homes are growing in popularity for several reasons — as we explain here.

Whereas solar storage was once seen as a novelty, it is now a viable option for many homeowners and not just for those looking to go “off-grid”. The advancement of technology and the government’s popular incentives and tariffs have seen to that.  

This post will teach you about the following topics so you understand whether a solar battery is right for you and your property. Once you’ve finished reading, an experienced solar installer can provide more advice.

In this article you’ll find the answers to the following solar battery frequently asked questions: 

• What are solar batteries?
• How do solar batteries work?
• What types of solar batteries are available?
• How much do solar batteries cost?
• How much energy can solar batteries store?
• How long do solar batteries last?
• What affects the length of time a battery lasts?
• What government incentives are available for solar batteries?
• How to choose a solar battery
• Do I need a solar battery at home? 

The United Kingdom has ambitious targets of reducing emissions by 78% by 2035 compared to the 1990 level. Each individual can help achieve this and embracing solar power and storage is just one way to contribute. 

Looking beyond 2035, the government has committed to net zero emissions by 2050, meaning there’s has been no better time to do your thing and embrace renewable energy in your home. 

We cannot tell you whether you need a solar battery in your home, although we can lay the facts down so you can make an informed decision yourself. First up, what are solar batteries and how do they work?

What are solar batteries?

Think of solar batteries like the regular batteries you’d find in your TV remote but on a much bigger scale. However, rather than storing energy for a device to change the channels, they’re storing photovoltaic (PV) energy generated from the sun’s energy by a solar panel system. 

With a solar battery, you’ll never need to worry about running out of power. With solar panels and a battery you could also go off-grid if you wanted, relying only on the energy created and stored in your solar setup to power your property. 

Additionally, as we explain in more detail further down the page, energy stored in a solar battery can be sold to the grid. Government initiatives also make it possible to earn money from this through tariffs and incentives. 

Unlike remote control batteries which run out of juice eventually, solar batteries don’t. Instead, they’re recharging whenever the solar system is generating power — which is most of the time (apart from during the night).

Solar batteries for homes are products for stori

How do solar batteries work? 

ng excess energy generated by solar panels. At one time this excess energy would’ve been exported directly to the grid, but with a battery, it doesn’t have to be.  

Each solar battery has a different capacity which indicates how much power it can hold. Did you also know that some batteries are stackable, meaning they can be joined together to generate added capacity? 

The depth of discharge (DoD) relates to how a battery can be used compared to its total capacity. A 100% DoD means the entire battery (e.g. 3.0kWh) can be used to power a home, whereas with a battery with a 96% DoD a total only that portion of the battery (2.8KwH of a 3.0kWh battery) can be used before another charge is required. 

As outlined in the next section, different battery types are more suited to different jobs. 

What types of solar batteries are available?

The two most widely used solar battery types on the market are lithium-ion and lead-acid. 

Lithium-ion batteries have the biggest market share despite being a relative newcomer. This is mainly because they have a long lifespan and higher usable capacity than other types of batteries. 

Alternatively, lead-acid batteries are available and have been since the 1800s. They’re still available because of their durability and reliability. Here are the benefits of each type: 

Lithium-ion 

• Long lifespan (due to higher discharge depth*) 
• Extended warranties (often 10+ years)

*Discharge depth relates to the amount of energy the battery can use before it needs charging. 

Lithium-ion batteries are best used for charging domestic properties because they can hold lots of power — more than lead-acid batteries for instance — within a relatively small space. 

Lead-acid 

• Traditionally the cheapest storage option
• Highly reliable
• Easy to dispose of or recycled (because the technology has been around for a long time)

Because they are so reliable lead-acid batteries are a great choice for off-grid solar systems while they make a good choice for backup batteries in case of emergencies. 

How much do solar batteries cost?

Solar batteries vary in price and the amount you pay will depend on your requirements. The size of your solar system dictates how much storage you require in turn the capacity and cost of the battery.

Like anything, different brands and models vary. Your main considerations will likely be the durability and capacity of a battery, so matching this up with your available budget is the best way to go. 

How much energy can solar batteries store?

How much a solar battery can store and how much storage you need are two different things. 

Consider both the size of your solar system and your energy usage habits. Let’s use a 5kW solar power system as an example to get an idea of how much storage you’ll realistically require. 

A 5kW system would create around 20kWh of energy on a good day, which is around 4,500 kWh over a year. Most systems without batteries feed around 13kWh back into the grid each day. 

For solar systems, this size of a battery between 10kW and a 13kW capacity is suggested so that the energy created is stored for use later such as during the night or even in the case of emergencies such as blackouts. 

As we covered earlier, the size of the battery you choose will come down to what you want to achieve. 

How long do solar batteries last?

The solar batteries currently on the market are designed to be operational for up to 15 years, although as the technology develops it is expected that the average lifespan will grow considerably.

While fifteen years is significant — and also the length of time it takes for the average solar setup to start paying for itself — as it stands, the battery will likely need to be replaced before the solar panels.  

Major manufacturers also cover their products with warranties, with the most common warranties lasting for ten years or 10,000 charge cycles (whatever comes first). 

What affects the length of time a battery lasts?

Various things determine the lifespan of a solar battery including how much it is used, the type of battery and the environment in which the solar battery is stored. Here’s more detail on that:

How often the battery is used 

Think about a phone battery and how regular charging reduces how long each charge lasts. It is inevitable as the battery becomes less and less effective over time — often it happens so slowly that we don’t notice. 

The same concept applies to solar batteries. If a solar battery is being used every night to power a property it will wear out much quicker than a battery being charged just for emergencies. Again living completely off-grid and using repeated charge cycles will wear the battery out more quickly. 

The type of battery you install

There are three types of solar batteries: lead-acid, lithium-ion, and saltwater. When looking at the three types, lithium-ion batteries are the longest lasting as well as offering the biggest storage capacity. 

See the section above for a more detailed breakdown of the three types of solar batteries. 

The environment where the battery is stored 

The area where a solar battery is stored should not be too hot or too cold. Instead, a dry and temperature-controlled environment is the best solution if you want a long-lasting battery. 

Manufacturers will have their advice for battery storage which will differ depending on the type of battery in question. General recommendations suggest the following solar battery storage temperatures: 

• Lead-acid — 4°C to 8°C
• Lithium-ion — -17°C to as high as 60°C

Both warmer and colder temperatures affect batteries, so a designated and controlled environment is what you should look for while storing a battery in direct sunlight should be avoided. 

Low-maintenance batteries can be stored inside your home whereas other batteries need a little more due care and attention so require housing in specific conditions, perhaps in a locked, well-ventilated box in a shed, garage or outhouse. 

In all cases, a solar battery should be stored within an area that has sufficient thermal mass, therefore absorbing heat energy so that it cannot affect the condition and performance of the battery. Common materials used to increase thermal mass are concrete, filled concrete and stone.  

Do you have any questions about solar batteries or panels? Speak to a dedicated solar battery expert. 

What government incentives are available for solar batteries

Before purchasing solar panels and a storage solution, you should learn about the following two government incentives which reduce the cost of solar battery installations and provide savings over a long-term period. 

VAT Reduction

If you are deemed eligible, you may qualify for a reduced rate of 5% VAT on the installation of several renewable technologies. Your supplier will charge you the reduced rate on the installation and any extra work. 

• Central heating and hot water system controls
• Draught stripping
• Wall, floors, ceilings and loft insulation
• Solar panels and storage 
• Ground-source heat pumps
• Air-source heat pumps
• Micro combined heat and power units
• Wood-fuelled boilers

Who is eligible? 

To qualify for the reduced VAT rate, you must be over 60 years old or be receiving one or more of the following UK government benefits: 

• Child Tax Credit (but not the family element)
• Council Tax Benefit
• Disability Living Allowance
• Personal Independence Payment
• A disablement pension
• Housing Benefit
• Jobseeker’s Allowance (income-based)
• Income Support
• War Disablement Pension
• Working Tax Credit

How to choose a solar battery

When looking for a solar battery to use with solar panels at your property you’ll want to consider the following three things, which will affect your system’s capacity and ability to produce electricity over a long-term period:

1. Battery life and warranty
2. Power capacity
3. Depth of discharge (DoD)

Another thing to consider is what you’re using the battery for. If you want to go off-grid altogether, experts recommend lead-acid batteries. Lithium-ion batteries on the other hand are great domestic batteries because they’re long-lasting, have large capacities and need a small area to be stored in. 

Do I need a solar battery at home? 

Solar batteries for homes are increasingly popular. If you have any questions about solar panels or what you’ve read about solar batteries in this article, our friendly team is more than happy to help.

For more insight into solar panels head to our blog where you’ll find articles on a variety of topics that will help you choose the right panels and understand important things like maintenance.