Comment: Tackling energy consumption woes with extended storage solutions

As the UK and the rest of the world race towards net zero, innovative solutions to harness energy from a multitude of renewable sources are at the forefront of this transformative journey.

However, ensuring the UK has sufficient levels of renewable energy to meet its domestic demands is only possible with a robust energy storage infrastructure. This vital framework bridges the gaps during times of low or no power generation from sources like wind and solar energy, ensuring a continuous and reliable energy supply.

Most grid-level or domestic energy storage solutions rely on conventional battery chemistries such as lithium-ion. However, these solutions fall short for large-scale energy storage infrastructure due to their inherent limitations. Lithium-ion batteries, for example, are cost-prohibitive, relying on scarce materials that drive prices up to around £1m per MWh installed. Additionally, their flammable electrolyte properties present a fire risk, making them unsuitable for critical settings like ports and airports.

Go with the flow

To tackle these challenges, the research team at Manchester University sees redox flow batteries (RFBs) as a less resource-intensive and more affordable solution, capable of storing energy for over 10 hours, making them the best candidate for long durable energy storage (LDES).

For decades, Redox Flow Batteries (RFBs) have proven their scalability and versatility. These systems typically feature two tanks to store charged electrolytes, allowing the separation of power and capacity. This unique design means a large tank with a small cell can deliver high energy with low power, while smaller tanks paired with a larger cell offer high power with lower energy. Their adaptable configuration makes RFBs a game-changer in energy storage solutions.

There are many large RFBs currently under development. One recently completed is a 100MW/400MWh system in Dalian, north eastern China. This system, like most commercial RFBs to date, uses vanadium as the ‘active’ metal. 

Many manufacturers use vanadium in their RFBs as they do not suffer from degradation and can therefore be cycled almost indefinitely, making it capable of a high level of throughput. However, the high cost and relative scarcity of vanadium have hindered the widespread adoption of Redox Flow Batteries (RFBs) as a mainstream energy storage solution. These challenges have so far kept RFBs from achieving their full potential in revolutionising the energy storage landscape.

A low cost solution

Our research aims to provide a more cost-effective solution for RFBs. We are developing systems that avoid the need for the use of rare materials such as vanadium. Our ‘post-vanadium’ developments offer additional benefits, including low flammability and non-corrosive properties, making them more accessible across various industries.

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Another key and expensive component of current RFBs is the membrane that separates the two ‘halves’ of the electrochemical cell. Our research aims to eliminate, the need for this membrane, significantly reducing costs and extending the lifespan of our flow batteries. Currently, the capital cost of RFB-based storage is around £250,000-350,000 per MWh – with our technology, we aim to reduce this cost to £100,000 per MWh offering significant savings and making sustainable energy storage far more accessible.

Innovation for net zero

To truly reach net zero emissions by 2050 and decarbonise our electricity system by 2035, the UK must make drastic changes to domestic and industrial power supplies, as these sectors represent a large percentage of overall energy use. Simply embracing renewables isn’t enough – LDES solutions are equally vital. The UK government must pair its transition to renewable electricity with a robust focus on new storage solutions to effectively ‘stockpile’ this renewable energy.

To rapidly scale up and reduce the cost of battery storage, the UK must significantly increase investment in technologies designed for longer-duration storage. This means developing new types of RFBs that move beyond our dependence on critical materials such as vanadium.

The Department for Energy Security and Net Zero recently pledged to create a framework that encourages investment in LDES, introducing a cap and floor scheme. They are also seeking views on various aspects of this new approach: eligibility criteria, design considerations, and options for the Powering up Britain Plan.

If the government moves forward with these plans, the consultation will offer revenue certainty for investors, ensuring a safety net if returns from operating assets fall below the agreed minimum.

Now is the time to implement new standards and frameworks to achieve our storage and net-zero targets. We urgently need affordable, safer, and longer-lasting energy storage solutions to support our expanding renewable energy supply. Cost-effective LDES technologies hold the potential to unlock a truly sustainable future.

Robert Dryfe, Professor of Physical Chemistry at Manchester University and founder of Haliogen Power