As the world transitions towards renewable energy sources, energy storage systems are poised to play a pivotal role in shaping the future of energy infrastructure over the next decade, in order to overcome the inherent drawback of renewables, namely their intermittency and variability and unlock the full potential of renewables.
Energy storage systems enhance grid stability and reliability, by providing fast-response capabilities and smoothing out variability in demand and generation. They enable peak shaving and load management, reducing strain on the grid and lower base load electricity costs.
Common types of utility-scale energy storage systems include Battery Energy Storage, Gravitational Storage (like Pumped Hydro), Compressed Air Energy Storage, Thermal Energy Storage and Hydrogen Energy Storage. Focusing on solar energy, we are dealing with those approaches which can enhance the reliability, dispatchability and efficiency of solar energy systems, namely:
Battery Energy Storage Systems (BESS) utilize electrochemical reactions, with lithium-ion batteries being predominant due to their energy density and fast response times; but suffering from limited scalability, safety concerns and economic challenges due to their high upfront costs, limited cycle life and degradation over time. They are typically well-suited for short-duration energy storage applications in PV plants, ranging from a few hours to several hours, depending on the battery technology and configuration.
Thermal Energy Storage (TES) manages the energy in heat format via sensible, latent or thermochemical approaches. It is mainly used in CSP plants and could provide longer-duration storage capabilities, ranging from several hours to several days or even weeks, depending on the size of the storage system and the thermal storage medium used. The stored heat can be later converted into electricity or used for heating and cooling applications and provide dispatchable power.
Hydrogen Energy Storage (H2) offers high energy density, long-duration storage, energy security, grid balancing capabilities. involves production of H2 using renewable energy. The produced and stored hydrogen, can later be utilized as a clean fuel for various applications, including transportation, industrial processes, including ammonia production for fertilizer, methanol production for chemicals and refining processes in the petrochemical industry, and also power generation through fuel cells or gas turbines.
These systems collectively ensure reliable and efficient utility-scale energy storage, which is critical for managing grid demand and supporting the integration of renewable energy in the transition to a sustainable and resilient future.