Pumped hydro storage plants: a review

Abstract

Pumped hydro storage plants (PHSP) are considered the most mature large-scale energy storage technology. Although Brazil stands out worldwide in terms of hydroelectric power generation, the use of PHSP in the country is practically nonexistent. Considering the advancement of variable renewable sources in the Brazilian electrical mix, and the need to provide flexibility to the national electrical system, several official documents cite PHSP as an important alternative for the expansion of the Brazilian electrical system. This article presents the state of the art of PHSP and its use, in order to create a theoretical basis for future research on the subject, also providing theoretical support for Brazilian energy planning. The review includes a global panorama on the use of PHSP in the world, the technical and projective foundations on this type of technology, its benefits, and disadvantages, in addition to the new configurations and possible layouts for the construction of pumped hydro storage plants. Finally, the challenges and trends for the dissemination of PHSP technology are addressed.

An Evaluation of Pumped Hydroelectric Storage Systems

“…In order for the transmission system operators to regulate the electricity grid, it must be able to feed from backup energy in seconds, minutes and hours. Storage hydroelectric power plants provide high energy quickly, which can meet the load demand in a short time in the order of minutes [2,24]. The disadvantages are the annual changes in the flow of the stream as an ecological effect.…”

“…It is affected by environmental conditions such as deterioration of land structure, sediments that may occur in water, and water evaporation. The high cost of installation, the risk of erosion in the place to be established and the transportation problem between the reservoirs can be disadvantages [2,24,33].…”

“…Since the generator is not connected to the grid, its rotation speed can be adjusted and optimized. Another major benefit of the variable speed pump turbine is which enhanced efficiency in turbine mode over fixed speed machines [2,34]. The variable speed unit can prevent power disturbances from random spikes and contributes to maintaining grid stability.…”

“…In addition, because it can provide a lower reservoir installation, construction and maintenance costs are reduced [37]. If it is well designed, it can be used in areas where it is difficult to utilize the conventional pumped storage system with long coastlines [2].…”

“…There are hourly, daily, monthly and annual fluctuations in renewable and clean energy sources. For example, wind power is the speed of the wind; ocean energy to changes in tide level by waves and currents; solar energy to solar radiation intensity; in hydroelectric power plants, it also depends on the flow rate of the stream [2]. Therefore, energy storage systems are required to provide quality power and to efficiently hold solar and wind power in grids.…”