Explain working of pumped storage plant.
2 Answers
Answer :
Pumped storage Hydro power plant: These power plants are used when quantity of water available for generation of electricity is limited or insufficient. The water from upper reservoir is passed through penstock to turbine, where its energy is converted in to electricity and then it is released in lower reservoir. The generation of electricity is usually carried out during peak load periods. During off-peak periods, the same water from lower reservoir is pumped back to upper reservoir. Thus the limited quantity of water can be reused again and again. For this kind of operation two types of arrangements are used:
i) Separate arrangement for pumping back the water: In this case separate pumps are used to lift the water from lower reservoir to upper reservoir.
ii) Reversible Turbine Pump Unit: In this arrangement, the machine is operated as turbine during electricity generation and the same machine is operated as pump to lift the water from lower reservoir to upper reservoir through penstock. The figure shows this arrangement. The energy utilized for pumping during off-peak period is recovered by electricitiy generation during peak period and same water is reused.
Answer :
Working of pumped storage hydroelectric power plant:- It consists of head water pond (reservoir) and tail water pond by constructing a dam at tail race path. Tail water pond and head water pond connected through penstock. During peak hours the turbine drives the generator and generates electrical energy. The excess energy generated by steam and nuclear plants during the off-peak load is utilized to drive the motors in the pumped storage plants During OFF peak hours the generator operates as a motor. And drives the turbine which now works as centrifugal pump. Raising the water from tail water pond to head water pond through penstock.