Oman: Exploring the potential of sand batteries for the Gulf

Zawya

26-05-2025

In the global quest for sustainable energy, the spotlight often shines on solar panels, wind turbines, and lithium-ion batteries. But in the quiet town of Kankaanpää, Finland, a modest silo packed with sand is rewriting the rules of energy storage; offering a promising solution to one of renewable energy's most stubborn challenges: what to do when the sun isn't shining and the wind isn't blowing.
The world's first commercial sand battery became operational in July 2022, the result of a collaboration between Finnish startup Polar Night Energy and local utility Vatajankoski (Polar Night Energy, 2022). The installation, a 7-meter-high steel container filled with around 100 tons of coarse sand, uses excess renewable electricity to heat air, which is then circulated through the sand, raising its temperature to about 600°C. The stored thermal energy is later used to supply the town's district heating network, warming homes and even a municipal swimming pool (BBC Future, 2022).
Unlike conventional batteries, which store electricity, sand batteries store heat - a key advantage in cold climates where heating demand exceeds electrical use. The Kankaanpää system delivers 100 kW of heating power with a thermal storage capacity of 8 MWh, allowing energy to be held for days or weeks with minimal loss (Polar Night Energy, 2022).
A second installation in Pornainen, southern Finland, is currently under development. Slated for commissioning in 2025, this larger unit will store up to 100 MWh using 2,000 tons of crushed soapstone, a byproduct of fireplace manufacturing. The system is expected to cut the town's oil-based heating use by over 60% (PV Magazine, 2024).
The simplicity and sustainability of sand battery technology make it especially appealing. Sand is abundant, affordable, and thermally stable. Unlike lithium-ion systems, sand batteries involve no toxic materials or rare earth elements and operate without moving parts—minimizing long-term maintenance and degradation (NREL, 2024).
Although the concept remains new, it is attracting global attention. The US National Renewable Energy Laboratory (NREL) has confirmed sand's potential for long-duration thermal storage, capable of maintaining high temperatures with minimal heat loss over time (NREL, 2024). Meanwhile, researchers in the United Arab Emirates have demonstrated that local desert sand can store solar energy at temperatures of up to 1,000°C, proving its viability for regional adaptation (Masdar Institute, 2017).
So far, no sand battery projects have been deployed in the Gulf. Energy storage in the GCC remains dominated by lithium-ion systems, such as Saudi Arabia's 1,000 MWh battery at the Red Sea Project (Red Sea Global, 2023) and the UAE's Masdar-led 5 GW solar-battery hybrid system (Financial Times, 2024). Yet the Gulf's abundant solar radiation, readily available desert sand, and commitment to decarbonization position it well for future sand battery implementation.
If adapted to local needs -particularly cooling- sand batteries could complement existing renewable strategies in the GCC. For example, thermal storage could be linked to concentrated solar power (CSP) systems or used in district cooling networks. These adaptations would support the region's goal of net-zero energy systems without relying heavily on imported battery materials.
While commercial use remains limited to Finland, sand batteries offer an elegant, low-cost path forward, particularly for regions seeking seasonal energy storage solutions without the footprint of chemical battery farms. As Polar Night Energy's team puts it, 'the future of clean energy may not only be in the sky, but beneath our feet.'
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