The specific operation is to find a relatively high place, build a huge reservoir here, and then build a water storage area of the same size under the reservoir. If the generated electricity is not used up, use the motor to lift the lower water to the higher reservoir for storage. When there is a power shortage, the water in the high reservoir is released and the potential energy generated by the height difference is used to generate electricity.
However, the disadvantages of pumped storage power stations are also obvious. First, the location of pumped storage power station is high, so it is necessary to build two adjacent large reservoirs. Moreover, there must be a certain height difference between the two, and most places do not meet the requirements. Secondly, there is a certain loss in the process of storage and conversion, and the conversion rate of electric energy is only about 70% to 80%. That is to say, the pumped storage power station stores 1 kwh of electricity, and only 0.7 to 0.8 kwh of electricity remains when it is sent out.
Then, besides pumped storage power stations, are there any other ways to store the scale of TV universities?
In addition to pumped storage power stations, compressed air is another commonly used method for large-scale storage of electric energy. First of all, when the power is surplus, we use a compressor to compress the air into high-pressure air. When electricity is needed, we release high-pressure air to drive the turbine to generate electricity, and convert the internal energy of high-pressure air into electric energy.
The method of compressed air sounds simple, but it is much more difficult to realize than pumped storage, and the most difficult problem is how to store high-pressure air.
Obviously, if high-pressure air is stored in a metal tank like liquefied petroleum gas, the cost alone will be unbearable. To solve this problem, the most mainstream solution in the world is to store high-pressure air underground, such as in abandoned mines or caves hundreds of meters underground.
This kind of power station using compressed air to store electric energy is also under construction in China, the largest of which is the Jintan salt cave gas storage project in Jiangsu, with a total investment of 5.5 billion. The project started in August 2020, with an initial planning of 60 MW and a long-term planning of 1 1,000 MW.
However, using high-pressure air to store electric energy has a great disadvantage, that is, the efficiency of converting high-pressure air into electric energy is too low, which can only reach 20% to 30%, and the remaining energy can only be wasted in conversion.
In addition to hydropower station and compressed air, scientists have also explored many strange energy storage methods, such as flywheel energy storage that converts electrical energy into mechanical energy, superconducting energy storage that converts electrical energy into magnetic field, and so on.