Liquefied Air Energy Storage: A Promising Solution

The global shift toward renewable electricity is making waves, now surpassing coal for the first time. However, the pressing question arises: how do we store this energy when the sun isn’t shining and the wind isn’t blowing? While some turn to large-scale lithium batteries and others to pumped hydroelectric systems, an emerging industry is championing an innovative approach: batteries that harness the power of air. In the northwest of England, near the village of Carrington, plans are underway for the world’s first commercial liquefied air energy storage facility. This ambitious project aims to transform surplus renewable energy into a powerful solution for energy demands.

The Challenge of Intermittency

The global transition to renewable energy is vital for reducing greenhouse gas emissions and avoiding severe climate change impacts. However, this transition poses challenges for power grids. Traditional fossil fuel power plants can quickly adjust their output to meet demand, providing a reliable electricity supply. In contrast, renewable sources like solar and wind are inconsistent; there are times when they don’t produce enough energy, risking blackouts, and other times when output exceeds demand, potentially harming the grid.

To address this, it’s essential to store excess energy for later use, ensuring stability and reducing the risk of network damage. Shaylin Cetegen, a chemical engineer at MIT, stresses the increasing importance of developing grid-scale storage capabilities to manage the growing reliance on renewable energy.

The Liquefied Air Solution

Historically, pumped hydroelectricity has dominated energy storage methods. Excess electricity is used to pump water uphill, which is then released back through turbines to generate power when needed, amounting to 160 gigawatts of global pumped hydro capacity as of 2021. Recently, the demand for energy storage has prompted rapid advancements in large-scale battery systems, expanding from 1 gigawatt in 2013 to over 85 gigawatts by 2023.

The technology for liquefied air energy storage is relatively new, with its conceptual roots dating back to 1977 but gaining attention only in the 21st century. The process involves three stages: first, air from the surroundings is cleaned; next, it is compressed to extremely high pressures; finally, it is cooled until it becomes liquid using a heat exchanger. “Power from the grid drives this charging process,” explains Cetegen.

When the grid needs additional energy, liquefied air is vaporized and converted back into gas, propelling turbines to generate electricity before being released back into the atmosphere.

Building the Future: A Commercial Facility

The new plant in Manchester signifies the first commercial-scale initiative globally. Developed by Highview Power, which has spent two decades refining liquefied air energy storage systems, it follows a pilot project in the nearby town of Pilsbury. The Carrington facility aims to store 300 megawatt-hours of electricity—enough to support around 480,000 homes during brief outages.

Anticipated to open in two phases, the facility’s turbine will begin operating in August 2026, stabilizing the electrical grid. Highview’s CEO, Richard Butland, points out that grid operators often resort to activating gas plants for stabilization, incurring hefty costs. By providing an alternative, the facility can help mitigate these expenses.

Economic Viability and Future Prospects

While the liquefied air system is expected to commence operations in 2027, its economic viability remains complex. Cetegen and her colleagues studied the feasibility of liquefied air energy storage across 18 U.S. regions, evaluating various decarbonization scenarios over 40 years. They found that, in the most ambitious scenario, liquefied air was viable in states like Florida and Texas but less so elsewhere.

This should not be misconstrued as a negative outcome. Cetegen highlights that other storage options, like pumped hydro and lithium batteries, also faced significant viability challenges. Their analysis indicated that the primary barrier was the insufficient renewable energy contribution to the U.S. grid, limiting the price volatility that would benefit storage facilities.

Importantly, liquefied air energy storage stands out for its cost-effectiveness. The levelized cost of storage can be as low as $45 per megawatt-hour, compared to $120 for pumped hydro and $175 for lithium-ion batteries. While none of these storage methods are currently economically viable without political backing, liquefied air presents a particularly promising alternative for large-scale storage solutions.

Ultimately, Butland envisions a future where power grids rely on a combination of storage technologies. Pumped hydro is incredibly effective but location-dependent, while batteries are efficient yet have shorter lifespans. Liquefied air, by contrast, offers the ability to store energy for extended periods with minimal losses. As countries navigate their green energy transitions, the demand for liquefied air energy storage may well grow significantly.

Conclusion

Liquefied air energy storage presents a compelling avenue for addressing energy storage challenges amid the rise of renewable energy. Its potential to stabilize grids while remaining economically viable positions it as a key player in the future of energy solutions.

• The shift to renewable energy has surpassed coal for the first time.
• Liquefied air energy storage could efficiently store excess renewable energy.
• The Carrington facility aims to support hundreds of thousands of homes during outages.
• Cost-effective energy storage solutions are essential for stabilizing power grids.