  Hydraulic Short Circuit (HSC) application allows the simultaneous pumping and
generating operations on different units of the same pumped hydro energy
storage (PHES) plants for the extension of the power consumption range. This
article proposes a methodology based on time-history statistics and CFD
numerical simulations to investigate the feasibility of integrating such a kind
of operation in pre-existing hydropower plants. The evaluation of the potential
power output and pressure drop analysis in the new HSC operation are presented.
The penstock trifurcation of a selected PHES plant is also analysed by CFD
simulations, by evaluating the loss-head coefficients and comparing the flow
conditions in different PHES operations.
