Uso de bombas funcionando como turbinas para a operação de miniusinas hidrelétricas reversíveis

Abstract

Historically, the Brazilian electrical matrix has been predominantly renewable, and this characteristic is expected to continue in the next decade. However, there is a gradual reduction in the relative energy storage capacity of the electrical system due to the increasing integration of non-dispatchable renewable sources and the lack of new hydropower storage plants. An alternative to enhance the energy storage capacity of the national electrical system, with proven international success, is pumped storage hydropower plants (PSH). This work is a case study aimed at analyzing the technical and economic feasibility of implementing a mini pumped storage hydropower with an installed capacity of approximately 200 kW. A theoretical comparative study was conducted between two generator group configurations: pump as turbine (PAT) and conventional hydraulic turbine. The PSH operates with a 15-hour charging cycle through the pump unit powered by the electrical grid with off-peak pricing, and a 6-hour generation cycle during peak hours through energy arbitrage. The results indicated that the PAT PSH configuration is more economically advantageous than the conventional turbine. In the current scenario, the proposed PSH has greater economic appeal than battery energy storage systems, however projections suggest significant reductions in battery costs over the next decade due to technological development and associated gains in scale. Thus, it is possible that batteries will become more economical compared to the mini PSH.