Batteries store energy in the form of chemical energy. They are essential for achieving carbon-free energy production, as they address the volatility of renewable energy sources. By storing energy when it’s available in abundance and distributing it when there’s a shortage, batteries improve grid stability and ensure a steady power supply.
Storing large quantities of hydrogen underground or in tanks not only allows one to store fluctuating renewable energy, but also to use it for various sectors of the economy, such as mobility, industry, or energy. It’s called ‘sector coupling’, and it’s a necessary step on our way to a carbon-free world.
Mechanical energy storage mainly uses compression and expansion to store and release energy as a Power-to-Power-storage. They improve the utilization of renewable energy sources by storing energy during low demand and releasing it during peak demand. This helps to balance the renewable load and prevents wasting energy through curtailment. Besides that, energy can be time-shifted to enable energy arbitrage.
Thermo-mechanical storage combines the technology of heat storage and mechanical energy storage (utilizing pressure and heat to store energy), mainly as standalone Power-to-Power-storage. It is well suited for bulk energy storage for re-electrification purposes. It can also be adopted to provide process heat and cold.
Pumped Hydro uses the gravitational potential energy of water in reservoirs. When electricity is needed, it’s allowed to flow through turbines, thereby creating energy. It´s cost-efficient and climate neutral. It also enables rebuilding the power grid in case of a blackout.
Rotating grid stabilizers use kinematic energy to provide additional inertia to the grid. This way, they support the existing grid infrastructure to handle renewable infeed. They also help to stabilize the grid by supplying quick power in case other power sources fail, and thus help to prevent blackouts.
Supercapacitors store electric charges. They have relatively low energy but high-power density that enables them to be charged and discharged quickly. For that reason, supercapacitors are often used at wind and solar farms for instant and uninterrupted power supply, as well as for grid stabilization.
Thermal storage supports decarbonization by storing renewable energy or waste heat as Power-to-Heat or Heat-to-Heat-storage. Reusing waste heat also improves the overall energy yield. The stored heat can be used in various industrial processes and makes them more flexible.