Chapter 11, Problem 12P

A hydroelectric power station is supplied from a reservoir having an area of 50 km2and a head of 50 m.If overall efficiency of the plant is 60%, find the rate at which the water level will fall when the stationis generating 30,000 kW

2. Consider the system described in the news: at night, when there is energy left, water is pumped from a large lake to a reservoir at 80 m above the lake level. During the day, this water is used to generate energy in a turbine located 80 m below the elevated reservoir. Considering that the water flow is always 5000 liters/s (both at the inlet of the reservoir and at the outlet) and that the pump and turbine efficiencies are 70%, what is the power (in kW) required by the pump and the power (in kW) recovered in the turbine. Data: The pipe diameter is always the same along the system (d = 0.5 m); g = 10 m/s2; γ = 9810 N/m3. Matter transport phenomena; Please make it typeable as handwriting interferes with understanding

What is the cost to pump 1000 liters of water to the top of a 30 m high water tank? Assume a pumping efficiency of 50% and an electrical cost of $0.15 per KW-h. P(h2O) = 1000 ?g/m^3 .   1 m^3 = 1000 liters