Comment: Long duration batteries can unlock low-carbon era

By the end of 2020, global energy storage capacity stood at around 170 GW, a substantial increase over the few gigawatts recorded in 2010. Through the rest of this decade, that figure is expected to skyrocket. The International Energy Agency (IEA) has projected that energy storage deployment needs to increase sixfold to support pledges made by 200 countries at COP28 to collectively triple renewable energy capacity to 11 TW by 2030.

Energy storage is needed to enable the integration of renewables, provide grid resilience, and support the electrification of transport. Greater demand for batteries over the past decade has helped attract investments in projects and technologies, driving down costs and accelerating technology advances.

Enhancing Grid Stability with LDES

Today, most grid-scale energy storage projects have durations of 2-4 hours, referring to the amount of time the battery can deliver its rated power capacity to the grid after a full charge. However, 2-4 hours is not adequate to meet the needs of a fully renewable grid. New long-duration energy storage (LDES) technologies will play a crucial role in ensuring that renewable energy is available when needed. These new LDES technologies rely on non-lithium battery chemistries and have the ability to safely store excess renewable energy during periods of peak generation, providing it back to the grid during periods of peak demand. This flexibility balances the grid, allowing more renewable sites to be integrated into the network and enabling the phase out of polluting fossil fuels while providing energy security and lower electricity bills.

Iron flow batteries (IFBs) differ significantly from lithium-ion batteries, the technology which powers most 2-4 hour storage systems. IFBs use a water-based, non-toxic electrolyte composed of iron, salt, and water. These safe, sustainable and widely available materials significantly reduce the risk of fire while leveraging transparent, flexible supply chains. Unlike lithium-ion batteries, which degrade over time, IFBs maintain their capacity over tens of thousands of cycles without degradation. Additionally, IFBs are scalable and cost-effective for large-scale applications, offering longer discharge durations and enhanced grid stability without the need for complex cooling systems​.

LDES systems using iron flow technology allow for localised energy production and storage, reducing the need for extensive and often vulnerable centralised power infrastructure. By offering scalable, cost-effective, and environmentally sustainable storage solutions, LDES helps create a more resilient and interconnected grid, capable of handling the dynamic and decentralised nature of modern renewable energy systems​.

Introducing Iron Flow Batteries

At Amsterdam Airport Schiphol, iron flow technology is set to be used in a pilot project as part of the airport’s plan to electrify its ground operations by phasing out diesel ground power units in favour of cleaner electric units. This transition will help the airport to reduce carbon emissions and air pollution, contributing to Schiphol’s goal of becoming a zero-emission airport by 2030. The project, supported by the EU-funded TULIPS consortium, aims to demonstrate the effectiveness of LDES in decarbonising airport operations and will potentially serve as a model for other European airports​.

Meanwhile in Germany, energy generator LEAG is planning to create Europe’s largest clean energy hub through a partnership facilitated by the Energy Resilience Leadership Group. The collaboration involves the potential deployment of a 50 MW/500 MWh iron flow battery system at the Boxberg Power Plant. The project is hoped to aid in LEAG’s transition from coal to renewable energy generation.

Preparing for the Future

Transitioning away from fossil fuels does not mean society will be reducing total energy demand. In fact, an increasing reliance on electric transportation and power-hungry technologies, such as AI, is set to drive continued growth in electricity demand.

The infrastructure to support that scale of growth will need to be considerably more flexible than existing grid networks, especially as governments and corporations set ambitious carbon neutrality and clean energy targets. For instance, Google Cloud has pledged to be carbon-free by 2030. Energy storage will play a critical role in achieving these goals, whether integrated to the broader energy grid, or by deploying microgrids to power specific applications, such as AI data centres or other major energy users, ensuring reliable power for critical infrastructure.

Mass deployment of sustainable LDES will ensure a consistent supply of green energy to power homes and industry while reducing the impact that increased electricity consumption will have on the grid and the climate.

Alan Greenshields is Director, EMEA, at ESS