Battery Storage Installation: A Guide

Installing a battery storage system in your home brings a number of benefits with it. From increased energy independence and reduced electricity bills, to the ability to store and use your own clean energy generated from solar panels. 

With prices of storage batteries coming down significantly in recent years, just like solar panels have done, it’s no wonder that batteries are quickly becoming a go-to for energy savvy homeowners aiming to bump up their renewable efforts. 

This article gives a comprehensive overview of the battery storage installation process, helping you understand the key considerations and steps involved in successfully integrating a battery storage system into your home.

Understanding Home Battery Storage Systems

Battery energy storage systems allow you to store electrical energy to use later on. The same premise applies from large scale utility batteries to those installed in your home. For homeowners it gives the opportunity to manage energy consumption more efficiently. 

Although there are numerous types of battery storage systems, including lead-acid, lithium-ion batteries are by far the most common for home battery systems. 

Alongside the main battery itself, there are a number of important components to a battery system. As electrical energy is stored as direct current (DC) in batteries, an inverter is needed to convert this into usable alternating current (AC) electricity to make it compatible with household appliances and the grid. The control management system monitors and regulates the battery’s performance, making sure everything is working optimally – it’s the brains of the operation. 

In most residential settings, battery storage systems work by storing excess energy generated from solar panels. They can also be charged during off-peak hours when electricity rates are lower, meaning battery systems can work independent of a solar PV array. Read more on getting started with battery storage. 

Battery storage installation scenarios

When it comes to installing battery storage systems, there are three main scenarios to consider:

Installing battery storage with new solar panels:

Installing battery storage simultaneously with new solar panels is the new go-to. Solar battery storage offers several advantages. By designing the entire system together from the start, installers can ensure optimal integration and compatibility between the components. 

This approach is easier from an installation perspective, minimises disruption and helps to reduce overall costs. 

Adding battery storage to an existing solar panel system:

For homeowners who already have solar panels installed, it’s possible to add battery storage retrospectively. In fact, adding battery storage is an excellent way to enhance your overall energy efficiency. 

However, it’s crucial to assess the compatibility of the existing solar panels and inverters with the new battery storage system. In some cases, retrofitting may require replacing or upgrading certain components. Good professional guidance here is key. 

Installing battery storage without solar panels:

Even without solar panels, battery storage systems can provide significant benefits. Standalone battery storage allows homeowners to take advantage of time-of-use electricity rates, storing energy during off-peak hours when prices are lower and using the stored energy during peak periods when rates are higher. This strategy can lead to substantial savings on electricity bills. 

Additionally, battery storage without solar panels can serve as a backup power source during power cuts, helping to keep your essential appliances and devices running.

You can read more about solar systems with or without batteries here. 

Choosing the right battery storage system

When it comes down to choosing a battery storage system, you’ll have a few things to bear in mind.

• Capacity – The battery’s capacity, measured in kilowatt-hours (kWh), determines how much overall energy it can store. You’ll need to consider your household’s energy consumption patterns, the amount of energy you regularly send to the grid (if you have solar panels) and future. More on sizing batteries in the next section.
• Power output – The power output indicates how much energy the battery can deliver at once. If you tend to run your dishwasher, tumble dryer and electric heating all at once, you’ll need to make sure your battery has a big enough power output. Read up on can battery storage power a house.
• Depth of discharge (DoD) – DoD refers to the percentage of the battery’s capacity that can be safely used without compromising its lifespan. A higher DoD allows for more usable energy and better overall efficiency. Modern batteries now operate at 90%+ DoD.
• Warranty and lifespan – Look for batteries with robust warranties and long lifespans. Many high-quality systems offer warranties of 10 years or more, giving you peace of mind and protection for your investment.

Choosing the right battery system also covers a number of other factors. Let’s take a look.

Sizing your battery

Properly sizing your battery storage system is a very important step. A battery that’s too big or too small reduces performance and creates inefficiencies for your home. 

To calculate your home’s energy storage requirements, consider the following factors:

1. Energy use – How much energy does your home use on an average day, week and month? This information will give you an idea of how much energy a battery could supply for you and how long the energy will last for.
2. Solar panel generation – If you have solar panels, how much energy are they producing on average? Or how much energy are new panels expected to produce? Knowing this alongside your energy use will help estimate how much energy you’ll have left over.
3. Energy export – If you already have solar panels, how much energy do you send to the grid on average? This information can be crucial in helping you identify the potential for storing and using this energy instead of exporting it (and then buying it back at a higher price).
4. Desired back-up power duration – If you want a battery for back-up power, consider how long you’d like to have cover for. You’ll need to know your average daily energy use for this.

Costs and financial considerations

The upfront costs of battery storage systems can vary significantly. It depends on capacity, technology, model and installation complexity. 

On average, homeowners can expect to pay between £4,500 and £10,000 for a well-sized battery storage system between 5-10kWh. A useful rule of thumb is to budget an additional £900 per kWh of storage capacity.

Although it’s a big sum to fork out initially, battery storage systems can provide significant long-term savings and a compelling return on investment, especially when paired with solar panels. 

Currently, there aren’t any direct government grants for installing battery storage, unlike what you can get with the Boiler Upgrade Scheme for heat pumps. However, from February 2024 there is a VAT relief on battery storage, essentially equaling a 20% discount.

Available installation space

Batteries don’t take up tons of space physically. The battery itself will be sized between a thin suitcase and a tall fridge freezer, but you’ll still need a good amount of room to install the battery pack, control system, inverter and accompanying wires and electrics. This will all need to be located ideally in a cool, dark space.  

Some common locations for installing a home battery system include lofts, utility rooms, storage cupboards and garages. Lofts are a popular choice, as they often have the space and are commonly used for solar inverters. Learn more on how big battery systems are. 

However, it’s essential to note that the battery system’s primary function is to monitor the grid connection, not the solar panels directly.

The battery storage installation process

Adding battery storage to your home is a multi-step process that involves careful thought and professional installation. As you go through the planning process, here are the main steps to think about:

• Research – Begin by conducting your own research into battery brands, systems and local installers to familiarise yourself with the available options. Gain a basic understanding of the technology. Reading this article may be part of your process already.

• Gather quotes – Contact a few companies to discuss your specific needs and get some quotes to compare. A good installer will visit your property beforehand to provide a tailored quote and expert advice based on your situation.

• Cost assessment – Evaluate the costs associated with purchasing and installing a battery energy system. Cost is always going to be a crucial step for most people.

• Battery system selection – Based on your research, consultations and price analysis, decide on the type of battery system you want, including the appropriate capacity for your needs. If you already have solar panels, you may have decisions to make on the integration method.

• Energy supplier agreement – Check with your energy supplier to determine if you need to update or change your agreement to get the best deal. This is particularly important if you intend on selling excess energy back to the grid under the SEG scheme.

• Location selection – Work with your installer to identify the best location for your battery storage system. Consider factors such as ventilation, temperature control, accessibility and available space.

• Installation – Arrange for a certified professional to install your new battery system and connect it to your solar panels if applicable.
• System configuration – Get the correct systems set up to track and optimise energy, consumption and storage, and general system performance.

To maximise the efficiency and benefits of your battery storage system, regularly monitor its performance and adapt your energy consumption patterns accordingly. 

By reviewing charging and discharging cycles and making necessary adjustments, you can ensure that your investment delivers the greatest possible returns in terms of cost savings and reduced reliance on the grid.