Evaluation of startup time for a model contra-rotating pump-turbine in pump-mode

Abstract A larger part of the electricity is today from intermittent renewable sources energy. However, energy production such varies in time. Energy storage one solution to compensate for this variation. Today pumped hydro (PHS) most common form storage. Usually, it requires a large head, which limits where can be built. In EU project ALPHEUS, PHS technologies low- ultra-low heads are explored. One concepts contra-rotating pump-turbine (CRPT). The behaviour design at time-varying load conditions scarce. present work, impact startup time CRPT analysed through computational fluid dynamics (CFD) simulations. analysis includes comparison between coarse and fine CFD model. model produces acceptable results 50 times cheaper, thus used assess It found that longer generate lesser loads peak values. 10 s may sufficient alternative as heavily reduced compared faster startups. Furthermore, there not much difference 20–30 s.