Pumped storage scheme is employed to supply power during the peak hours.

Explanation:

Pumped storage is a type of hydroelectric energy storage system that is used to balance the supply and demand of electricity. It involves utilizing two reservoirs at different elevations and a reversible turbine to generate electricity.

Here is a detailed explanation of why pumped storage scheme is employed to supply power during the peak hours:

1. Peak Load Demand: During the peak hours, there is a high demand for electricity due to increased consumption by residential, commercial, and industrial sectors. The existing power generation capacity may not be sufficient to meet this peak load demand.

2. Energy Storage: Pumped storage provides a means to store excess electricity during periods of low demand or off-peak hours. This excess electricity is used to pump water from a lower reservoir to a higher reservoir.

3. Pumping Phase: During the off-peak hours when electricity demand is relatively low, the excess electricity from the grid is used to operate pumps that lift water from the lower reservoir to the higher reservoir. This process requires energy but does not generate electricity.

4. Generation Phase: During peak hours when there is a high demand for electricity, the stored water in the upper reservoir is released through turbines. As the water flows down, it drives the turbines, which in turn generate electricity. This generated electricity is then supplied to the grid to meet the peak load demand.

5. Efficiency: Pumped storage systems have high efficiency in terms of energy conversion. The energy used during the pumping phase is recovered during the generation phase, resulting in a high overall efficiency of the system.

6. Quick Response: Pumped storage systems have the advantage of quick response time. They can be started and stopped rapidly to match the fluctuating demand for electricity during peak hours.

7. Grid Stability: By supplying electricity during peak hours, pumped storage schemes help to stabilize the grid and prevent blackouts or disruptions in power supply.

In conclusion, the pumped storage scheme is employed to supply power during the peak hours when there is a high demand for electricity. It helps to balance the supply and demand, ensures grid stability, and provides an efficient means of energy storage.

Pumped storage plants can act as both pump and turbine. During low demand period it pumps water to upper reservoir, during high demand time it generates electricity by releasing stored water through turbine