The quest for a sustainable future is not just about generating green energy, but also about storing this energy efficiently to account for fluctuations in generation and demand. As the world gradually shifts its reliance to renewable energy sources like solar and wind power, the traditional mainstays of energy storage, lithium-ion batteries, and their kin are being rivaled by a potentially game-changing contender: heat. Spearheaded by innovative startups, the burgeoning field of thermal energy storage is demonstrating how excess energy can be effectively stored as heat, potentially offering more cost-effective and environmentally friendly solutions. With the ability to cater to industries with intensive heat demands where batteries are less efficient, these technologies are essential in the push towards a low-carbon future.
The Molten Salt Movement
Molten salt technology is steering the energy storage sector in new directions, with companies such as the Kyoto Group leading the charge. The Norwegian enterprise has developed the Heatcube, a storage system that contains highly heat-retentive salt capable of reaching 500°C. This solution is particularly advantageous for industrial processes that require substantial amounts of heat, showcasing the inadequacy of pure electrical batteries for such applications. Iberdrola, through its investment in Kyoto, has lent credibility to this approach, drawing on Spain’s decade-long experience of utilizing molten salt to turn solar power into electricity well into the night. This demonstrated potential not only highlights the versatile applications of salt in energy storage but also its practicality on an industrial scale.
The concrete benefits of such molten salt systems are manifold, not least their ability to deliver on the significant heat demands within industries. By providing a stable high-temperature heat source, this form of energy storage can sustain numerous industrial activities during periods when renewable sources might be limited. Spanning a wide range of potential uses, from manufacturing processes to power generation, molten salt storage devices like the Heatcube signify a departure from conventional battery storage toward solutions that can uniquely address the challenges posed by a rapidly transitioning energy landscape.
Complementing Current Technologies with Salt
Malta Inc., a promising initiative stemming from Alphabet’s X innovation lab, has thrown its hat into the thermal storage ring with its own unique approach to utilizing salt. Malta’s heat storage technology is not just about keeping the lights on; it’s geared toward providing reliable backup power generation – an indispensable asset as society contends with the intermittency of renewable energy sources. Storing energy as heat in large tanks of salt and antifreeze, Malta’s system is characterized by its potential for longevity and efficiency, reputed to last up to 40 years with minimal deterioration.
The beauty of Malta’s system lies in its simplicity and robustness. The modular design means scaling up is essentially a matter of adding more salt tanks, and with salt being abundant and non-toxic, there are significant sustainability and safety perks. These features are crucial for a future where renewable energy systems need to be as adaptable and durable as possible. Malta envisions a world where salt storage systems work in harmony with other forms of energy storage; a world where the diversity of energy needs can be met with an equally diverse toolkit of reliable, efficient, and environmentally friendly storage options.
Cost-Effective Heat Storage in Bricks
The California-based company Rondo is revolutionizing heat storage with its brick-based heat battery, challenging the status quo of energy storage economics. Able to heat bricks up to a staggering 1,500°C, the Rondo system showcases the potential to maintain energy for several days with little to no loss. This capability is a game-changer, with the company claiming energy storage costs that undercut both green hydrogen and chemical batteries by as much as half. With substantial cost savings and increased efficiency, Rondo’s technology offers a promising roadmap to the future of sustainable energy management.
Rondo’s brick-based system demonstrates the scalability of thermal storage; it can be enlarged simply by adding more bricks. This scalability makes it an attractive proposition for industries reliant on high-temperature processes. By ensuring that the energy stored during times of surplus can be retained for extended periods without significant losses, the bricks serve as both a buffer against energy volatility and a reliable heat source that can be tapped into as needed, seamlessly transforming excess renewable energy into a stable, on-demand industrial resource.
The Phase-Change Revolution
British innovator Sunamp is bringing phase-change materials (PCMs) into the energy storage conversation. Used in their systems much like the gel in hand-warmers, PCMs can absorb and release heat energy, providing an efficient medium for both heat and cold storage. Sunamp’s technology is making waves with its assertion that it is four times more efficient than traditional water tanks, a claim that has secured it governmental support and funding for trials. This groundbreaking technology stands poised to radically upscale the efficiency of thermal storage and carve out a significant niche in the global energy sector.
The ingenuity of Sunamp’s approach is underscored by the system’s adaptability to a variety of settings, from residential heating to commercial and industrial applications. The use of PCMs enables the storage of large amounts of energy in a relatively small volume, thus optimizing space and increasing energy retrieval rates. With its ability to swiftly absorb and release heat, Sunamp’s system proposes a means to mitigate the unpredictability of renewable energy sources, effectively harmonizing energy generation with consumption patterns across diverse grid networks.
Compressed Air and Liquid Air Systems
The UK’s Highview Power is advancing compressed air energy storage with its development of an ambitious 250MW facility near Manchester. This innovative approach capitalizes on the concept of storing energy as compressed air, which can be converted back into electricity when demand peaks. Central to Highview Power’s tech is the reduction of grid curtailment issues, particularly in high wind scenarios when turbines are often forced to stop despite available wind.
Collaborative efforts such as that between Highview Power and energy titan Ørsted showcase the potential for integrated storage solutions with wind farms, signaling a progressive stride toward a more versatile grid infrastructure. This synergy aims to amplify the utility and efficiency of wind power, propelling us closer to energy systems resilient against the fluctuations of renewable energy sources. The endeavors of Cheesecake Energy further diversify the compressed air energy storage landscape, with their own system to generate electricity from compressed air further illustrating the breadth and potential of these emergent technologies.
Storage in Concrete and Steel
Swiss firm EnergyNest and Germany’s Lumenion are broadening the horizons of energy storage with their focus on heating specialized concrete and steel modules. This industrial approach to thermal storage speaks volumes about the cooperative international effort to meet the burgeoning energy storage demand. These companies are tailoring their solutions to the grid’s needs, leveraging the thermal capacities of heavy-duty materials to carve out a unique space in the energy storage ecosystem.
These concrete and steel thermal batteries provide insight into just how versatile energy storage can be. They cater to different scales of energy demand, from localized grid support to large-scale industrial applications, illustrating the potential for thermal energy storage solutions to fit a myriad of roles in the evolving landscape of energy storage. With the intrinsic stability and endurance of such materials, these technological advancements are paving the way for reliable and long-lasting energy storage solutions, which can confidently meet the demands of a renewable-powered world.
The Economic and Environmental Advantage
Thermal storage’s star is on the rise, a rise supported by a comprehensive analysis by McKinsey, which underlines the viability of heat-based solutions in terms of cost and environmental impact. As the report suggests, the compelling price-per-megawatt-hour comparison favors thermal storage when pitted against conventional storage options. Nevertheless, the report does not shy away from the challenges that new technologies face, particularly those related to the commercial market and policy support.
As the clock ticks on carbon emission reduction goals, the energy storage sector must leave no stone unturned in its search for solutions, including emerging thermal technologies. Despite the inherent inertia of transitioning from well-established methods to novel ones, pilot projects set the stage for these technologies to gain the visibility and validation they need. It’s a race against time to pivot to sustainable energy storage, but the diversity and potential of our current technological toolkit offer optimism for a cleaner, more resilient, and more cost-effective energy future.
