Rui Castro, researcher at INESC ID and full Professor at Instituto Superior Técnico, authored an opinion article published in the newspaper “Jornal i” titled “Energy storage systems in the electrical grid: What are we waiting for?” (“Sistemas de armazenamento de energia na rede elétrica: Estamos à espera de quê?”).

The article discusses the complexity of the electrical power system and its dependence on a wide variety of different generator types each one with its own characteristics, from natural gas, to hydroelectric, wind, and solar power. Rui Castro emphasizes a fundamental constraint regarding the power system, which is that the balance between electricity production and consumption must be met at every second. This restriction is pivotal for the safe operation of the electrical grid.

The article approaches two promising alternatives for energy storage: batteries and hydrogen. The INESC ID researcher acknowledges that it is possible with current battery technology to store and later release large amounts of electrical energy at a national level, but the high cost is still an issue. Nevertheless, the author predicts that soon, as technology advances and the cost of batteries decreases, this will be a competitive and economically viable option for large-scale energy storage. Regarding hydrogen, the production process through electrolysis during periods of low energy consumption is still expensive and inefficient. However, technological advancements are expected to make it viable in the longer term.

Both are considered viable options for energy storage and helpful for power system’s stability, with batteries expected to become competitive sooner. At the same time, hydrogen may be an alternative in the longer term, depending on technological advancements and cost reductions.

According to Rui Castro, Portugal needs to anticipate and prepare a future centered on an electrical system able to rely almost 100% on renewable energy sources. As a closing observation, the INESC ID researcher highlights that it is urgent to invest in efficient energy storage systems. The question is: what are we waiting for?

Full article here.