Energy from sea waves is one o the main trends in research and development concerning
power potential from the ocean, many types of devices and ideas are being developed
around the world with the aim of finding an economical and reliable alternative energy
source. The power in waves is massive but it is also is of the type extensive, meaning
that to harvest sufficient amount of energy to make an economical use of this energy
several or massive devices have to be installed, often requiring great ocean areas.
As more efficient devices are developed the practicality use of these devices will
make them more financially attractive, for now still at small scale systems stage
The main factors to consider for the development and installation of an ocean waves
power generation system are the wave amplitude, the wave period and the waves generation
over long periods of time, they are places in which good waves suited for power generation
lasts only few weeks a year, while others maintain an average quality wave generation
for a full year, so the proper location selection is of the foremost importance.
Ocean waves are always being generated but unfortunately regularity in amplitude
and frequency is not a constant, their average parameters can change during the day,
week, month and season of the year and even from hour to hour, therefore any ocean
waves based power generating project requires a careful evaluation of wave system
not only for one short period of time but for the full year, this is very important
to calculate how much power can be harvested during the entire year to estimate if
it makes economical sense.
Basic Waves Parameters Definitions
Period: Is the time elapsed between peak to peak or valley to valley in a wave
Frequency: Is how many times a wave completes a cycle in a period of time, in ocean
the wave frequency is normally only few cycles per minute or a fraction of it.
Wave length: Is the distance between peak to peak, valley to valley or from start
Wave amplitude: Is the vertical dimension of the wave measured from peak to peak
The basic equations that define a simple wave are:
f = v/ג ; where:
f = frequency of the wave,
v = speed at which the wave moves in the horizontal plane,
ג = is the length of the wave
Reciprocating Electric Generator
Uses a movable magnetic core that moves up and down following the waves crest and
The system is formed by a stationary coil in which the magnetic core runs up and
down generating an alternating voltage. The generator can be connected to a different
power conditioning arrangements, or convert it to DC power using a rectifier circuits,
then convert it to
back to AC in a controlled manner without depending on the waves period and frequency.
The Waves Reciprocating Compressor
Another wave reciprocating system is the reciprocating compressor, works by allowing
the wave penetrates in a vertical tubular enclosed shape with a top air escape hole,
while the wave is in the upward motion the air is forced and expelled through a pipe
connected to a cylinder-piston and then to flywheel to convert the reciprocating
movement of the cylinder to circular motion.
Please note that the system works in two ways, in the air compression cycle when
the wave is going upwards and in the vacuum cycle when the wave going downwards producing
a sucking effect that pulls the piston in the opposite direction reinforcing the
flywheel circular motion.
The circulation motion of the flywheel can be connected then to any desired device
to generate any other mechanical or electrical energy, such as compressors, air or
water pumps or an electric power generator.