Date: February 17, 2015
Source: SINTEF
Summary:
Researchers are demonstrating that it is possible for a
redundant fishing vessel to be used as a power plant. The first vessel of its
kind is now anchored offshore in the Stadthavet area west in Norway, with the
aim of generating electricity from the natural forces of the sea.
Is
it possible for a redundant fishing vessel to be used as a power plant?
Absolutely! The first vessel of its kind is now anchored offshore in the
Stadthavet area west in Norway, with the aim of generating electricity from the
natural forces of the sea.
The
idea is as brilliant as it is simple.
"In principle, it works almost like a bicycle
pump" says engineer and Project Manager Edgar Kvernevik at Kvernevik
Engineering AS.
For the last two years his company has been working with
Geir Arne Solheim, the founder of Havkraft AS and the man who came up with the
idea, to develop and build the wave power plant now installed in a former
trawler/autoline vessel.
But how do you get a fishing vessel to work like a gigantic
bicycle pump?
The makers have met this challenge by installing four large
chambers in the vessel's bow. As the waves strike the vessel, the water level
in the chambers rises. This creates an increase in air pressure which in turn
drives four turbines -- one for each chamber. The pitch of the vessel also
contributes by generating additional air pressure in the chambers when the wave
height is large. The design of the chambers is such that they work in response
to different wave heights, which means that the energy is exploited very
effectively.
"The plant thus produces electricity with the help of
what is called a fluctuating water column," explains Kvernevik, who has
spent much of his working life designing and building vessels. "All we
have to do is to let the vessel swing at anchor in a part of the ocean with
sufficient wave energy. Everything is designed to be remotely-controlled from
onshore," he says.
New application of a tried and trusted principle
The company Havkraft AS, which came up with the original
concept, is based in Raudeberg in Nordfjord. Solheim, the company's founder,
has been working here with wave energy for more than 15 years. The company is
now receiving funding from Innovation Norway to help put the idea into
practice.
The "fluctuating water column" concept is a tried
and trusted approach. However, installing a wave energy plant inside a fishing
vessel is something no-one has done before.
"This floating power plant has also been equipped with
a special anchoring system which means that it is always facing into the
incoming waves," explains Kvernevik. "This ensures that the plant is
in the optimal position at all times," he says.
Full overview of energy production
But Havkraft AS is not alone. One of the organisations
contributing to the project is MARINTEK, which has developed a mathematical
model and run a number of simulations of the plant. This has provided
developers with a better overall picture of how much energy can be extracted
from the waves. The project has advanced on the basis of analyses, model
experiments and full-scale simulations.
"The use of simulations and dynamic analyses, in
combination with model experiments, has enabled us to avoid beating repeatedly
around the bush using the standard approach of trying out different scales of
model," says Kvernevik. "This has saved us time and money. We now
have a full-scale model constructed and installed," he says.
The nominal capacity of the plant is 4 x 50kW -- 200kW in
total. MARINTEK's computations indicate that the plant is capable of producing
320,000 kWh per year.
Advanced engineering
Even though the principle behind the plant is simple, there
is a lot of advanced engineering installed on board.
None of the moving parts are in direct contact with salt
water. In fact, the only moving parts are the turbines, which are installed
above the vessel's deck. Moreover, it is constructed so that it runs the same
way regardless of whether the chambers are "inhaling" or
"exhaling." The vessel is currently located offshore Stadtlandet, in
an area where the company Stadt Wind AS has a renewable energy testing licence.
This is one of three test sites in the Stadthavet area, which together comprise
the so-called Stadt Test Area.
A study of an offshore wind farm (the 1080MW Stadtwind
project, involving floating wind turbines) was previously carried out in the
same area. The Norwegian Water Resources and Energy Directorate (NVE)
subsequently declared the area as one of the few in Norway suitable for the installation
of floating offshore wind farms. The annual average wind speed measured in the
area is 11 m/s, which is higher than any other location in Norway, including
the North Sea. This indicates that the area is clearly well suited to the
exploitation of renewable energy from wind and waves, which is interesting
because in the long-term, the project plans to look into the possibility of
combining floating wave power plants with wind turbines.
Hydrogen production
"We see this project as a three-stage rocket,"
says Kvernevik.
"The first stage is to test the model we have just
built to make sure that electricity generation can be carried out as planned.
Next, a hydrogen production plant will be installed on board the vessel so that
the electricity generated can be stored in the form of hydrogen gas. We have
high hopes that hydrogen will be the car fuel of the future. Our aim is to work
with others to produce hydrogen at a competitive price -- based on an infinite
resource and involving no harmful emissions," says Kvernevik
optimistically.
"The plan is then to construct a plant with a nominal
capacity of 1000kW (1MW). We will do this by installing five production modules
similar to the current plant either on a larger vessel or a custom-built barge.
Finally, we will build a semi-submersible platform designed to carry a 4MW wave
power plant with a 6MW wind turbine installed on top," he says.
MARINTEK in Trondheim is one of the project partners which
have contributed towards the development of the wave power plant.
"We have built a basic computational model of the
plant," says MARINTEK's Jørgen Hals Todalshaug, a hydrodynamicist and an
expert in wave energy. The project will now be running a series of field tests
at sea which will provide Havkraft AS with experience of how the plant works
under operational conditions.
The tests will also provide quantitative data that can be
used to improve and calibrate the computational model, and thus improve its
accuracy.
Story Source:
The above story is based on materials provided by SINTEF. The original article was written
by Christina Benjaminsen. Note:
Materials may be edited for content and length.
Cite This Page:
SINTEF.
"Fishing vessel transformed into a wave power plant." ScienceDaily.
ScienceDaily, 9 February 2015.
<www.sciencedaily.com/releases/2015/02/150209094940.htm>.
FROM,….
SCIENCEDAILY.COM
