Lenze's new international sales structure

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Electricity from wave power
Ocean waves represent an enormous reservoir of energy. The World Energy Council conservatively
estimates their usable potential at 2000 TWh worldwide if existing technologies are fully realised
in areas with good wave conditions. If sites with less ideal wave condiitons also are included, the
potential increases to 15,000 TWh. One of the research and pilot projects currently underway to make
this energy source usable is being conducted by Harvesting Technologies, for which the Swedish sys-
tem integrator Avalon, working with Lenze, has developed effective and revealing simulations. The
central element is a 9300 series servo controller with integrated cam technology.
From a statistical point of view, average wave states can
be determined for locations near the coast, and the equipment
used can then be optimised according to these
states. Tides, winter storms, mild summer breezes – everything
has an effect on the surface of the sea. “A wave
power station must therefore be designed to be as flexible
as possible so that it can follow these changes as
dynamically as possible”, emphasised Svante Logeke,
product manager at Avalon. But how can waves be simulated
as authentically as possible so that conclusions can
be drawn and applied to future power stations? This was
The functional principle behind the Swedish “Ocean Harvester”, a 50 kW
model of which is to be tested at sea in 2011.
the question that Ocean Harvesting Technologies had to
answer with its test facility. Wave models developed by
Blekinge Technologieinstitut were used as the basis. The
Swedish system integrator Avalon designed and constructed
the test rig with the crucial support of the
Swedish Lenze company.
The motion concept
The test facility has been designed to create robust systems
with which wave energy on the oceans can be
harvested as efficiently as possible. The patented principle
of the Ocean Harvester uses a buoy-like construction that
is kept in place by an anchor cable attached to the seabed.
When a wave causes an upswell, the buoy rises and thus
reaches a higher energy level. This is used in two ways.
First, the anchor cable directly drives an initial drum,
which in turn feeds in a forward direction a mechanical
power takeoff integrated into the buoy, driving a generator.
Next, a second drum with a cable connected to a
counterweight is rotated in a direction that raises the
counterweight while maintaining a constant torque in
the power take-off. When the buoy descends in the next
trough between waves, the input shaft in the power takeoff
is prevented from reversing while the counterweight
continues to drive the generator with previously stored
kinetic energy. In this way, the oscillating movement of