Storage systems are particularly useful if you have a renewable energy installation as they allow you to use more of the clean energy you have generated, which could help further reduce your energy bills and carbon emissions.
Storage systems allow you to store excess power from your renewable system, buy cheaper electricity at night and store it for use during the day. In some cases these storage devices can provide back-up supplies for use in a power cut, but this is not always possible and you should check with your installer.
The introduction of smart meters also enables a greater range of two-way metering of electricity (import and export) and time-of-use tariffs, allowing you to pay different rates for electricity purchased at different times of the day. Some of these tariffs are available for non-smart meter customers too.
Storage systems fall into two categories: thermal stores and batteries.
Thermal stores are highly insulated tanks that can store heat as hot water for several hours. They vary in size from around 120 - 500 litres or more and can be used with solar, wind, biomass and hydro renewable systems.
Electricity batteries can also help you make the most of electricity generated from solar, wind or hydro systems. For example, your solar PV system will generate electricity during the day when you're out at work, which can be stored in your electricity battery to use in the evening.
Or, your business can reduce energy costs by charging the battery when energy is cheaper – either at night via the grid when tariffs are lower and/or during the day with excess solar – and ‘shifting’ this power to periods when energy is expensive during the day. Operating the battery this way will typically flatten out your company’s demand for energy from the grid.
It’s important to consider if using a storage system will be cost effective for your installation. Good quality systems are expensive and will need replacing every five to ten years depending on how much they're used. In addition, batteries are not 100% efficient, so you will not get all of the energy out that you put in.
Vehicle to grid technology (V2G) enables energy stored in EVs to be fed back into the electricity network. This means that if you have your own generation, such as solar panels, you could charge your vehicles using any excess energy produced from your generator and store the energy in your EV battery for later use. This means you could benefit from time-of-use tariffs by charging your vehicles when energy prices are cheaper and discharging this energy to the grid when prices are high. This also helps reduce peak demand on the electricity network.
Here's where to go for more advice on installing your renewable energy system.