Question

In the water behind 110m high dm the temperature difference between the water's surface and the bottom is 10C. The constant-colume het capacity per unit mass is 4.2kJ/kg/C. The temperature at the water's surface is 22C.

a) Compute how much energy per unit mass could be obtained by extracting heat form the water. Assume the heat extracted in a process that has the same efficiency as a Carnot engine.

b) Compute the energy per unit mass that could be obtained by letting the water flow over the dam to a turn at the bottom.

c) Compare these two vlues, which method yields more energy? By how much? Discuss how realistic these values are and how realistic you think the differences are.

Answer 1