The energy gains realisable through pumping for tidal range energy schemes

•We systematically explore energy gains from pumping for barrages and lagoons.•The analysis uses first principles and computer modelling.•Optimistic claims shown to be unachievable – realistic energy gains ∼10%.

Some previous work has made optimistic claims about the potential energy gains that could be made by using pumping with tidal range structures (barrages, lagoons and offshore tidal impoundments). This paper explores the factors influencing whether such gains can be realised for positive head pumping (pumping once water levels have equalised), using 0-D modelling concepts.