Get Started With The Basics Of Home Battery Storage

Are you looking to learn more about battery storage? Do you want to get to grips with the basics without being bogged down with all the technicalities and jargon?

This is an important step. If you’re going to invest in a battery storage system, it’s a great idea to have a base level understanding. 

This guide aims to get you started with residential battery storage. We’ve stripped everything back to give you all of the information you need to know in the simplest manner to get you off the mark. 

What is Home Battery Storage?

A home battery storage system is a device that stores electrical energy for later use. There are two main ways to send electricity to your battery for storage:

  • From your own renewable energy sources like solar panels
  • From the national grid during off-peak hours

Stored energy can then be used during peak demand when electricity prices are high or when renewable sources aren’t generating power, such as at night or on overcast days.

Battery storage is gaining traction as part of a more sustainable future for homes across the UK. It will form a key part of the plan in reducing greenhouse gas emissions and  transitioning to a cleaner, more resilient energy system.

Market trends show a gradual rise in home battery storage system adoption with the most recent statistics showing around 10,000 UK installations, mostly alongside solar panel systems. This number is a few years old, so there are likely many more domestic battery installations in the UK.  

How does home battery storage work?

When your home’s energy needs have been met, any excess electricity can be sent to your battery storage system. Just like a regular battery, this energy is then stored until it’s required to be put to use around your home.

Battery storage systems can work seamlessly with both solar panels and the national grid – yes, you can have battery storage without solar panels. In this case, the battery is charged using electricity from the grid during off-peak hours when energy prices are typically lower. The stored energy can then be used during peak hours when energy prices are higher, helping you to save money on electricity bills.

In a home with solar panels, the battery storage system can store excess energy generated during the day, which can then be used during periods of low or no solar energy production. This helps to optimise and make use of the solar energy your panels are producing.

There are two main types of lithium-ion battery energy storage systems:

  • AC-coupled: AC systems connect to the home’s electrical system after the solar inverter. This is the easiest way to retrofit a battery into an already existing solar array. 
  • DC-coupled: These systems connect directly to the solar panels before the inverter. As electrical energy is stored as DC (direct current), this system is generally more efficient as it minimises energy losses during the conversion process.

Without battery storage, it’s possible to send excess energy from your panels to the grid and get paid for it, but you’ll have to buy it back at a higher rate. Not efficient. You can read more on advice for solar panels with or without battery storage in our full guide.

And finally, it’s important to note that battery storage can be retrofitted into homes with solar panels. Solar panels can also be retrofitted to work with a battery system but this is the less common way to do things.

Types of battery storage systems

When it comes to home battery storage systems, there’s one main choice for the type of battery: lithium-ion. These types are the most common and widely used in residential battery energy storage systems. 

This is because they don’t take up a lot of space for the energy they provide (high energy density), have a long lifespan and low maintenance requirements. 

Lithium-ion batteries also have a higher depth of discharge. This means they can be discharged more fully without damaging the battery. 

Other types of storage batteries include lead-acid and flow batteries.

Lead-acid batteries are an older technology that has been used in various applications for many years. Whilst they are generally less expensive than lithium-ion batteries, they have a lower energy density, shorter lifespan and require more maintenance. 

Flow batteries are a newer technology that is primarily used in large-scale utility projects. Flow batteries have a long lifespan and can be easily scaled up, making them suitable for large-scale energy storage applications. However, they are not commonly used in residential settings due to their size and complexity.

Sizing your home battery storage system

When choosing a home battery storage system, it’s key to select the most appropriate size possible to meet your household’s energy needs. There are several factors at play that determine the optimal battery size for your home.

The most important is how much energy your home uses on a daily basis. Understanding how much energy you typically use will help you determine the battery capacity required to meet your needs. This is simple enough. 

The average home in the UK uses around 6-10kWh of electricity per day. So, roughly speaking, a 10kWh storage battery would give you enough power for a day’s worth of energy. That said, your home will use more power in the winter than it does during the summer.

It’s not quite apples for apples in terms of storage and power output as you need to take into account the depth of discharge of the battery. This is how much power it can give out without damaging itself. For example, it can be harmful for some batteries to be completely drained to 0%. Also, powering multiple devices at the same time from your battery, can decrease its charge more quickly. For more insights here, check out our post on whether battery storage can power a house.

Next, it’s wise to consider the available space in your home for installing the battery storage system. You’ll need to ensure you have sufficient space to accommodate the system, which includes the battery itself, plus the control box, inverter, wiring, as well as space to ventilate the units. You can find more info here on how big are home battery storage systems, which includes size dimensions and the best places to have systems installed. 

A professional installer will help you determine the appropriate size for your specific needs and home setup.

How long do solar batteries last for?

When investing in a solar battery storage, you’ll want to know how long the system lasts for. This directly impacts the cost-effectiveness and overall efficiency of your renewable energy setup. 

Although solar panels typically last around 30 years, the lifespan of the accompanying battery storage may differ.

On average, solar batteries have a lifespan of 10 to 12 years, with some models lasting up to 15 years or more. Higher quality storage batteries, such as those from Enphase IQ, come with a 15 year warranty. 

These batteries are designed to handle daily charging and discharging cycles, but like any rechargeable device, their performance gradually declines over time. In terms of charging cycles, a battery usually operates between 6,000 to 10,000 cycles before its effectiveness decreases – you can read more on how long storage batteries last for in a separate guide!

It’s worth knowing that a storage battery has around half the lifespan of a solar panel, which can last around 30 years. 

Costs and financial considerations of home battery storage

The cost of residential battery storage varies widely depending on several factors, such as the system’s capacity, technology type and how it’s integrated into your current systems. Installation costs also contribute to the overall price, making it difficult to provide a one-size-fits-all answer. However, in the interest of giving you an idea, we’ll give it a go. 

Homeowners can generally expect to pay between £4,500 and £10,000 for a well-sized home battery storage system. The minimum you can expect to pay for a small battery is £2,500. A helpful rule of thumb is to budget around £900 per kWh of extra storage capacity. For example, a 5 kWh system would cost around £4,500, while a 10 kWh system could reach £9,000 or more. 

These costs are all for a lithium-ion battery. Whilst lead-acid batteries may be slightly cheaper, they’re not a long-term option.

Financial support from the government for battery storage is few and far between, but there’s a couple of small incentives. 

In 2022, battery storage was exempt from VAT when installed with solar panels. From February 2024, this VAT reduction has been brought back but without having to invest in solar panels or other green technology. This essentially equals a 20% discount. Solar panels are also currently exempt from VAT. 

There’s also the Smart Export Guarantee (SEG) scheme, which pays homeowners for storing and exporting excess energy.

Benefits of using battery storage at home

Battery energy storage systems give homeowners a number of advantages over households without them.

One of the most significant benefits is the potential to lower electricity bills. By storing energy from the grid during off-peak hours when rates are lower and using that stored energy during peak hours when rates are higher, you can reduce your energy costs. This works even without a solar PV connection, as long as you have a suitable time-of-use tariff. 

When combined with solar panels, it’s thought that battery storage can help you save up to 70% on your annual electricity bills. We worked out that it can save you around £800 a year.

Battery storage also allows you to maximise the consumption of your own generated energy when you have solar panels installed. This increases your self-reliance and the overall efficiency of your renewable system. Although you can export excess solar energy to the grid, the rates paid for exported energy are significantly lower than the cost of buying electricity back from the grid.

In addition to financial benefits, home battery storage contributes to a cleaner environment by reducing the dependence on fossil fuels. When paired with renewable energy sources like solar panels, you can power your home primarily with the energy from the sun. At the end of your battery’s life, the component parts can be recycled rather than sent to landfill.

As the world transitions towards cleaner and more sustainable energy solutions, investing in a home battery storage system can help future-proof your home and prepare you for upcoming developments in the energy sector. It’s also thought that they’ll add value to your home and increase saleability, with green tech something that homebuyers are actively looking for.

About the author 

Ben Hardman

Ben is a professional writer and the creator of sustainable living website
It's here where he helps people to reduce their environmental impact through simple, everyday choices. Away from the laptop, Ben loves spending time in the natural environment with his young family and Murphy the cocker spaniel.

First Class BSc Biology degree (environmental and climate change focus)
Six years of working and writing in the environmental sector, including two years working at an international sustainability consultancy
Written for Ethical Consumer magazine, My Mother Tree, Unsustainable Magazine, Happy Eco News, Emission Index,
Commented in The Independent, The Guardian, GreenMatch. Also featured on Radio 1's environmental special 'Minute of Me'

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