Utility-scale energy storage systems: World condition and Brazilian perspectives

The integration of intermittent renewable energy sources (RES) into the grid significantly changes the scenario of the distribution network's operations. Such challenges are minimized by the incorporation of utility-scale energy storage systems (ESS), providing flexibility and reliability to the electrical system. Despite the benefits brought by ESS, the technology still has limited investment and application in Brazil. The financial viability of ESS, in the current Brazilian regulatory framework, is unlikely. Thus, this article discusses the main regulatory aspects that are being adopted in countries that are at the forefront of implementing an ESS and the application possibilities for regulatory adequacy in the Brazilian scenario. In this scenario of absolute lack of regulation, some points for the development of a regulatory framework are listed, classified into four dimensions: (i) definition; (ii) grid access mechanisms; (iii) remuneration mechanisms; (iv) types of services. The key-findings and policy implications encompass: the need to create an electricity energy storage agent, enabling the generation of multiple revenues, and avoiding double taxation; the time granularity will need to be expanded, aiming at improving the market's sensitivity to economic signals; the regulatory framework could define a minimum payout for storage services, as well as a stimulus to investments in utility-scale ESS through subsidized credit lines; and industrial policies for the development of the production chain of facilities and devices related to the energy storage sector should be further discussed. Thus, the planning of the Brazilian regulatory framework must be thought of in the long-term and strategically.