The waters of the oceans hide innumerable wealth, the main of which, perhaps, are unlimited sources of energy in the form of sea waves. For the first time, the use of kinetic energy of shafts rolling on the shore was conceived in the 18th century in Paris, where the first patent for a wave mill was presented. Now technology has stepped far forward, and with the joint efforts of scientists, the first commercial wave power station, which began to be operated in 2008, was created.
Why is it profitable?
It's no secret that natural wealth is on the verge of exhaustion. Reserves of coal, oil and gas - the main energy sources - are coming to an end. According to the most optimistic forecasts of scientists, reserves are enough for 150-300 years of life. Nuclear power also did not live up to expectations. Large capacity and productivity pays off the costs of construction, operation, but the problems of landfill and environmental damage will soon force to abandon them. For these reasons, scientists are looking for new alternative energy sources. Wind and solar power stations are already operating. But for all their merits, they have a significant drawback - low efficiency. It will not be possible to satisfy the needs of the entire population. Therefore, new solutions are needed.
A wave power plant uses the kinetic energy of the waves to generate electricity. According to the most conservative estimates, this potential is estimated at 2 million MW, which is comparable to 1,000 nuclear power plants operating at full capacity, and about 75 kW / m per one meter of wave front. In this case, there is absolutely no harmful effect on the environment.
General scheme of work
Wave power plants are called floating structures that are able to convert the mechanical energy of the waves into electrical energy and transmit it to the consumer. At the same time, they try to use two sources:
- Kinetic reserves. Sea shafts pass through a large-diameter pipe and rotate the blades, which transmit force to the electric generator. The pneumatic principle is also applied - water, penetrating into a special chamber, displaces oxygen from there, which is redirected through the channel system and rotates the turbine blades.
- Rolling energy. In this case, the wave power station acts as a float. Moving in space along with the wave profile, it makes the turbine rotate through a complex system of levers.
Different countries use their own technologies for converting the mechanical movement of waves into electricity, but the general scheme of action is the same.
Disadvantages of wave power plants
The main obstacle to the extensive introduction of wave power plants is their cost. Due to the complex design and complex installation on the surface of sea waters, the cost of introducing such installations into operation is higher than the construction of nuclear power plants or thermal power plants.
In addition, there are a number of other shortcomings, which are mainly associated with the emergence of socio-economic problems. The thing is that large float stations pose a danger and interfere with navigation and fishing - a float wave power station can simply force a person out of fishing zones. Environmental consequences are possible. The use of installations significantly extinguishes sea shafts, makes them smaller and prevents them from breaking through to the shore. Meanwhile, the waves play an important role in the process of gas exchange of the ocean, cleaning its surface. All this can lead to a shift in the ecological balance.
Positive aspects of wave power plants
Along with the shortcomings, a wave power plant has a number of advantages that have a positive effect on human activities:
- installations, due to the fact that they extinguish the energy of the wave, can protect coastal structures (moorings, ports) from destruction by the power of the ocean;
- electricity is generated at minimal cost;
- high wave power makes wind farms economically more profitable than wind or solar power plants.
Water reserves are also possessed by land waters, mainly rivers. The construction of stations on bridges, crossings, moorings is a prospect for the development of this area of electricity generation.
Problems to be Solved
The main task facing the scientific community now is to improve the design, which will reduce the cost of electricity generated by wave power plants. The principle of work should remain the same, but new technologies and materials will already be applied to create plants.
The average wave power is 75-85 kW / m - this is the range most stations are tuned to. However, during a storm, the strength of sea shafts increases several times and there is a danger of destruction of installations. Already more than one blade was crumpled or bent after a storm. To solve this problem, scientists reduce the specific power of the waves by artificial methods. One of the problems is that the massive use of wave stations will lead to climate change. Electric energy is generated by the rotation of the Earth (this is how waves form). The widespread use of stations will make the planet rotate more slowly. A person will not feel the difference, but it will destroy a number of currents that play an important role in the heat transfer of the Earth.
The world's first experimental wind farm
The first wave power station appeared in 1985 in Norway. Its power was 500 kW, and she herself was a prototype. Its operating principle is based on cyclic compression and expansion of the medium:
- a cylinder with an open bottom is immersed in water so that its edge is below the hollow of the wave — its lowest point;
- periodically running water compresses the air in the inner cavity;
- upon reaching a certain pressure, a valve opens, which allows compressed oxygen to pass to the turbine.
Such a power plant generated 500 kW of energy so that it was enough to confirm the effectiveness of the plants, which contributed to their development.
The world's first industrial power station
The world's first industrial-scale facility is Oceanlinx in Port Kemb, Australia. It was commissioned in 2005, but then it was sent for reconstruction and in 2009 it started working again, which is why the region now uses both tidal and wave power plants. Its principle of action is as follows:
- Waves periodically run into special chambers, causing air to compress.
- Upon reaching critical pressure, compressed air rotates the generator through a network of channels.
- To capture the movement and strength of the waves, the turbine blades change their angle of inclination.
The power of the installation was about 450 kW, although each section of the station is capable of generating from 100 kW * h to 1.5 MW * h of electric energy.
The world's first commercial wind farm
The first commercial wave power plant was launched in 2008 in Agusador, Portugal. Moreover, it is the first installation in the world that uses directly the mechanical energy of the wave. The project was prepared by the English company Pelamis Wave Power.
The structure includes several sections that are released and raised along with the wave profile. The sections are pivotally attached to the hydraulic system and drive it during movement. The hydraulic mechanism forces the generator rotor to rotate, which generates electricity. The wave power plants used in Portugal have pros and cons. The advantage of the installation is its high power - about 2.25 MW, as well as the possibility of installing additional sections. There is only one drawback of installing the system - there are difficulties with the transmission of electrical energy by wire to the consumer.
Russia's first wave power plant
In Russia, the first wind farm appeared in 2014 in the Primorsky Territory. The team of scientists from the Ural Federal University and the Pacific Oceanological Institute of the Far Eastern Branch of the Russian Academy of Sciences was engaged in the development. The installation is experimental in nature. Its peculiarity is that it uses the energy of not only waves, but also tides.
In Moscow, the construction of a research laboratory is planned, which will develop and create the first domestic float station. Perhaps after this, wave power plants in Russia will also have industrial or commercial purposes.