Battery Energy Storage Systems (BESS)

The role of battery energy storage systems (BESS) in securing GB’s low-carbon electricity grid

The UK government has set ambitious goals for transforming our electricity grid, aiming to fully decarbonise the power sector by 2035 by:

• targeting 95% low-carbon electricity by 2030, a major milestone towards a clean energy future
• maximising renewable energy generation, which has consistently contributed around 50% of the UK’s electricity
• reducing our reliance on fossil fuels
• reducing our reliance on other countries for our electricity.

Keeping the electricity grid stable is incredibly important, but most people never think about how it happens, and our aim is that you shouldn’t have to. At Statkraft, we develop clever solutions, which we call Greener Grid Parks, using infrastructure at strategic locations across Great Britain, to help make our electricity network resilient and fit for the future.  

A low-carbon electricity grid is crucial for tackling climate change, and renewables, such as wind and solar, are an important part of this transformation. the transition to renewables needs to come with flexible solutions that step in to ensure there’s always enough power supply to meet demand, and ensure power supply is uninterrupted. When combined with solutions that manage fluctuations in supply and demand, renewables can effectively meet consumer demand and provide a reliable electricity supply.

Currently, the UK is heavily reliant on natural gas to balance energy fluctuations and maintain this grid stability. Yet the IPCC warns that fossil fuel emissions must be halved within 11 years if global warming is to be limited to 1.5°C above pre-industrial levels, the target identified as part of the Paris Climate Agreement. If the UK is to achieve its own zero-carbon targets, whilst achieving greater energy independence and the associated benefits, it must reduce its reliance on natural gas.

In the past, fossil fuel power plants have been used to manage grid stability and peak demand, but battery energy storage facilities can replace a proportion of this. Therefore, a decarbonised power system will need to be supported by technologies that can respond to fluctuations in supply and demand, including energy storage. Demand for UK grid energy storage is expected to rise to 10 gigawatt hours (GWh) by 2030 and to 20 GWh by 2035.

This is where we see the need to rapidly scale up low-carbon energy storage solutions, with batteries (or BESS) being a crucial component in the UK’s future energy mix.

BESS technology is a cost-effective solution for the UK

The UK government estimates that using technologies like BESS to support the integration of more low-carbon power, heat and transport technologies could save the UK energy system up to £40 billion by 2050, and could help to reduce people’s energy bills by improving efficiency. Furthermore, the UK government’s Energy Security Plan, Powering Up Britain, aims to proactively secure the UK’s energy independence by reducing reliance on volatile international energy markets.

How does a battery storage system work?

A battery is a device that stores electrical energy as chemical energy that can be released on demand. Batteries can be rechargeable or non-rechargeable. Non-rechargeable batteries are typically used in household devices such as torches. Batteries are often made from smaller individual compartments, called cells, that can be linked together.

Rechargeable batteries, such as lithium-ion batteries, are used for applications that have greater energy demand – for example, mobile phones, electric vehicles and grid storage. These batteries operate on a simple principle. During charging, electrical energy is converted into chemical energy as tiny lithium particles move from one electrode to the other through a conductive material found in each cell. During discharging, the process is reversed, releasing the stored chemical energy as electrical energy.

Importantly, this process allows excess electricity to be stored and then released when needed, ensuring a reliable and consistent electricity supply.

• Rechargeable batteries can store and release energy many times.
• Battery storage systems are far more advanced than typical household batteries.
• These systems can be charged by renewable energy sources like wind and solar.
• Intelligent software and computer control determine when to store or release energy to the grid.
• Energy is released during peak demand to lower costs and maintain electricity flow.

What makes a good site?

BESS are typically housed in modular units that resemble small shipping containers, which can be strategically located near power plants, substations or renewable energy sites, such as solar farms and wind farms. This co-location optimises space and infrastructure, can reduce transmission losses and enhances the overall efficiency of the energy system.

The core components of BESS include the batteries for storing energy, a system that monitors and manages them to ensure they operate safely and efficiently, and equipment that converts