Optimization of pump selection for running as turbine and performance analysis within the regulation schemes

Highlights: • Substituting pressure reducing stations with hydropower plant was investigated. • Optimal PAT selection was performed under variable hydraulic conditions. • Design criteria were improved to consider PAT characteristics. • The performance of plant components was analyzed from energy perspective. • Regulating schemes were compared in terms of effectiveness and economy. Increasing Renewable energies efficiency and harnessing the available potentials are among the goals that have been addressed in sustainable development. Helping to promote the utilization of these valuable and reliable sources can provide a basis for their worldwide expansion. Pump as turbine (PAT) is a suitable device to generate clean energy from hydraulic potentials. One of the main challenges of using a PAT is the lack of control tools on the flow, which affects mainly the off-design performance of the machine. In this paper, the criteria of pump selection for running in turbine mode were modified under variable head and discharge conditions by improving existing performance indicators and introducing availability. The effect of operating schemes was studied on optimal pump specifications with the effectiveness criterion consisting of capability, availability and adaptability. The performance of power plant components was investigated in regulating the flow and reducing the potential. Using a case study in Iran, dual regulation is the most effective scheme with an effectiveness of 0.4037, but mechanical scheme had the most capability with 0.4230. The results showed that compared to using average values of head and discharge for pump selection, optimization could increase the effectiveness up to 20%.