Question

Ocean Thermal Energy Conversion (OTEC) generates electricity using the difference between the temperatures at the surface of the ocean, where the water is warm, and far below the surface, where the water is cool. A test system off Hawaii operated between temperatures of 28 °C (the water temperature at the surface) and 5 °C (the temperature far below the surface), and operated with an efficiency of 2.3%.

(a) What is the theoretical maximum efficiency we could expect from this system?

At the actual efficiency of 2.3%, lets say the plant generates electricity at the rate of 125 MW.

(b) At what rate is energy being removed from the warm surface water?

(c) At what rate is energy being deposited into the cooler sub-surface water?

Answer 1

DATA:

SOLUTION:

Part a)

The theoretical maximum efficiency is defined as:

Replacing values of data given we obtain:

Solving we obtain:

Part b)

We have,

Isolating we have:

Replacing values:

Solving we obtain:

Part c)

By the equation

Replacing values we have:

Solving we obtain: