Central Sardinia isn’t typically seen as an innovation hotspot. Arid and rural, with road signs bearing bullet holes from locals using them for target practice, the setting resembles a scene from a Clint Eastwood western. However, in Ottana, on the site of a former petrochemical plant, a groundbreaking technology is emerging that could help combat climate change. Surprisingly, the main component of this technology is carbon dioxide, the primary culprit behind global warming.
Energy Dome, a startup based in Milan, operates an energy-storage demonstration plant that addresses an imbalance in the local electricity market. “In Sardinia, during the day, everyone heads to the sea,” explained Claudio Spadacini, CEO of Energy Dome. “They don’t use much electricity, but there’s an excess supply,” he added, referring to the island’s plentiful sunlight.
Using a massive balloon filled with carbon dioxide, which gives the company its name, Energy Dome utilizes the gas as a form of battery. Throughout the day, electricity from the grid, including power generated by nearby solar fields, is used to compress the carbon dioxide into liquid form. At night, the liquid is expanded back into gas, powering a turbine to generate electricity that is fed back into the grid.
While solar and wind power are rapidly growing renewable energy sources, they depend on nature’s unpredictable schedule for electricity production. Many experts argue that storing this energy for later use, spanning hours or even days, is crucial for shifting economies away from fossil fuels. “Advancing energy-storage technologies is vital for achieving a decarbonized power grid,” stated Jennifer M. Granholm, the U.S. energy secretary, in a 2022 announcement pledging over $300 million for long-duration energy storage.
Various companies are exploring innovative methods to store renewable energy, such as liquefying carbon dioxide, de-rusting iron, or heating sand-filled towers to nearly aluminum-melting temperatures. However, predicting our future energy storage needs post a significant energy transition is a daunting task, and the effectiveness and profitability of these approaches remain uncertain.
“There is a pressing need to decarbonize electricity within a much shorter timeframe than previously thought,” noted Elaine Hart, founding principal at Moment Energy Insights LLC, a clean-energy consultancy. “While we may not require technologies like long-duration energy storage or hydrogen immediately, they may be essential on a large scale within the next 15 to 20 years, making this a critical period for their advancement.”
