Wave power generation brings exclusive ＂mobile charging treasure＂

In the sea area south of Zhuhai, Guangdong, a silver-gray triangular device fluctuates with the waves. It is 27 meters high, weighs about 6,000 tons, and has a plane area of over 3,500 square meters, which is equivalent to the size of about 8 basketball courts.

This is the world’s first megawatt floating wave power generation device "Nankun" independently developed by China, with an average daily power generation of 10,000 kWh, which can meet the daily electricity demand of about 1,500 households.

Wave energy is mainly the energy generated by the periodic movement of seawater along the horizontal direction caused by the action of wind. In the ocean, a huge wave can throw 13 tons of rock 20 meters high, with amazing energy. It is estimated that the global ocean wave energy can reach 2 billion to 3 billion kilowatts, which is close to or even more than 100 Three Gorges hydropower stations.

"Many islands are far away from the land power grid, mainly relying on diesel engines for power supply, with high power generation costs and great environmental protection pressure. China has a long coastline, a large marine land area and abundant wave energy resources, which can effectively reduce the proportion of island diesel power generation. " Liang Xiaobing, deputy chief engineer of Guangdong Electric Power Research Institute of China Southern Power Grid, said that the wave power generation device is equivalent to installing a "mobile charging treasure" for the remote island reef.

It is not easy to make the turbulent waves become a "helper" for power generation. Among them, there are two hurdles that are the hardest to cross.

First, improve energy conversion efficiency. Wave energy is converted into electric energy through three stages: the capture device absorbs wave energy, which is converted into mechanical energy through the transmission device, and then converted into electric energy through the generator set. The energy loss is high, so the capacity of the previous device is several hundred kilowatts.

Wang Wei, a technical expert from Guangdong Power Grid, said that Nankun adopted a triangular design in appearance to absorb as many waves as possible while maintaining stability. What’s more, Nankun also adopts adaptive wave power generation technology, automatically adjusts the generator set according to the wave size, and realizes "all staff are on duty when the wave is big" and "shift rest" when the wave is small, turning the original big and small waves into continuous, stable and smooth current, and the energy capture efficiency is about 28%, reaching the international leading position.

Second, ensure the reliable operation of equipment. The equipment is located in the ocean, so it should not only be able to withstand typhoons, but also prevent seawater. When the wind and waves are extremely heavy, Nankun will start a key-in water mode and dive to a safe depth to resist the typhoon. Up to now, Nankun has successfully withstood the test of typhoons such as Capricorn, Ginkgo biloba and Weipa, and can hold the 5.5-meter-high waves. "’Nankun’ has been designed according to the standards of seaworthy ships and passed the certification of China Classification Society." Wang Wei said.

In addition to wave energy, tidal energy, tidal energy, temperature difference energy and salt difference energy are all available marine green renewable energy. Up to now, the installed capacity of wave energy, tidal energy and tidal energy in China ranks first, second and third respectively in the world, and the marine energy equipment is basically synchronized with the international advanced level, accumulating rich engineering and technical experience, laying a good foundation for realizing large-scale utilization.

The Guiding Opinions on Promoting the Large-scale Utilization of Marine Energy issued this year proposes that the installed capacity of marine energy should reach 400,000 kilowatts by 2030. Support the pilot project construction of marine energy utilization, sum up and popularize the pilot experience, steadily increase the scale of the project, and promote the cost reduction and industrialization development by scale.

The relevant person in charge of the New Energy and Renewable Energy Department of the National Energy Administration said that in the next step, the National Energy Administration will work with relevant departments to solidly promote the survey of marine energy resources in pilot areas and promote them in coastal areas throughout the country in due course; Actively promote the development of offshore wind power and wave energy in the same field, and improve the efficiency of marine resources development; Strengthen policy guidance and institutional guarantee, and accelerate the large-scale utilization of marine energy.

Source: People’s Daily