Page 394 - Handbook of Energy Engineering Calculations

2. Find the energy and power densities

Note: Because of the large depth, the semiaxes are equal, so the motion is
circular. Note also that they are small compared with the wavelength, so the
water motion is primarily vertical.

Related Calculations. Two-meter waves, of course, do not occur all the time.
However, in regions of high wave activity, 2 m is a median with heavier and

calmer seas occurring about 50 percent of the time. The total energy and
power densities over a period of time should take this spectrum into account.
2
With these densities proportional to a , the average densities would be greater
than the values obtained here.
It is instructive to compare these values with the average daily solar
incidence where, in the southwestern United States, a value of 240 W/m 2
2
(0.0223 kW/ft ) is often used. Thus, wave-power density is much higher. A
complete comparison should take into account the efficiency of conversion to
electric energy as well as other factors, like capital costs for land and

equipment, operational costs, costs of energy storage, and other factors.
This calculation procedure is the work of M. M. El-Wakil given in his
excellent text, Powerplant Technology, McGraw-Hill, 1984 and 2002. The