Wind farms provide a steady stream of green power for local economic development. I believe that many people have had such doubts: This windmill turns so slowly, how many kilowatt-hours can it produce in one turn?

Let’s start with the principle of wind turbine power generation.

Wind turbines are composed of basic components such as impellers, nacelles, and towers. Its power generation principle is very simple: the unit uses the wind force to drive the windmill impeller to rotate, and converts the wind energy into mechanical energy, and the generator converts the mechanical energy into electrical energy, and then the electrical energy is transmitted to the booster station of the wind farm through the collector line, and then delivered to The power grid can become clean wind power used by thousands of households.

But a wind farm consists of dozens or even hundreds of windmills. How do so many windmills work?
Each windmill is controlled by the main control room, the “central brain” of the wind farm, and the staff responsible for the operation of the wind turbines monitors 24 hours a day to ensure the safety and health of the windmills.

How much electricity can be generated by the blades of a windmill turning around?

Under normal circumstances, as long as the wind speed reaches 3 m/s, the windmill can rotate to generate electricity.

Taking a 1500-kilowatt fan unit as an example, the blades of the unit are about 35 meters long (about 12 stories high). It takes about 4-5 seconds for the wind turbine to rotate once (but at this time, the blade tip speed can reach more than 280 kilometers per hour, which is comparable to the speed of a high-speed rail), and can generate about 1.4 kilowatt-hours of electricity. Under normal full power conditions, the power generated in one day can be used by 15 households for one year. Such a wind turbine can reduce the emission of 3,000 tons of carbon dioxide, 15 tons of sulfur dioxide, and 9 tons of nitrogen dioxide per year.

For example, the wind farm in the western mountainous area of Huangyan has a total land area of 1.6727 hectares, and installed 28 wind turbines with a unit capacity of 1,500 kilowatts. Does wind power generation mean that the bigger the wind, the better?

According to the law of conservation of energy, it is true that the higher the wind speed, the more electricity will be provided, but our wind energy converter will be damaged due to excessive strength when the wind speed reaches a certain value, and in fact, the power generation does not depend on the blade speed.

Because there is a device similar to a car gearbox in the wind turbine unit, for example, if the gearbox is set to 1st gear, even if the blades rotate very fast (equivalent to stepping on the accelerator), it is still relatively difficult to drive them to the generator device through the gearbox. Constant low speed (equivalent to the car still not running fast), with such a device, the direction change also plays a protective role. In the case of a constant speed of the blade, the power of the blade will increase as the force on the blade increases. The larger the blade of the fan, the greater the power, and the corresponding power generation will be more.

Don’t worry, the head of the wind turbine is integrated with a sensor and a yaw system. Once the wind vane and anemometer collect changes in wind direction and wind speed, the yaw system will urge the yaw motor to adjust the position of the cabin so that it can be aligned with the wind direction smoothly. Use wind energy with maximum efficiency.

Wind power is also subdivided into onshore wind power and offshore wind power.

There is a big difference in construction cost between the two. Generally speaking, the construction cost of offshore wind farms is twice that of onshore wind farms, and the operation and maintenance costs are 2-4 times that of onshore wind farms. This is mainly due to poor offshore construction conditions and high construction difficulty. In addition, offshore wind power is far away from the shore, and unfavorable sea conditions such as typhoons and storm surges will also have a greater impact on wind power operation and maintenance.

Why should we continue to develop wind power offshore?

The sea is vast and has abundant wind energy resources. Offshore wind power generation has high utilization hours, does not occupy land, does not consume water resources, and is suitable for large-scale development. The power generation efficiency is generally 20%-40% higher than that of land wind power. To achieve carbon peak, wind power has great potential.

Wind energy is a renewable energy source, very environmentally friendly. Moreover, wind energy facilities have less impact on the ecological environment. Although the initial investment is large, compared with hydropower and thermal power, the later maintenance and management costs are extremely low. It is currently one of the power generation methods with the most mature technology, the most large-scale development conditions and commercial development in the field of new energy.

However, wind is an intermittent renewable energy source, and its power varies greatly in a short period of time, but its power is relatively stable for a long time. This makes it impossible for wind power to increase or decrease power generation according to demand, and cannot be used as a base load power source. Therefore, wind power must be used together with other power sources or storage facilities to provide a stable power supply. As wind power increases in the region, more conventional energy sources such as thermal power and nuclear power may be needed as backup or to upgrade the grid.

However, power management technologies can be used to solve these problems, such as dispatching different renewable energy sources and generating units with different geographical distribution, importing and exporting power to adjacent areas, and storing energy. Therefore, grid companies are currently exploring how to achieve large-scale consumption of new energy.