There are also hydroelectric power stations in the mountains!
The largest pumped storage power station built this century is located on Fengning Mountain in Chengde City, Hebei Province, where there are two large reservoirs at an altitude of 1,486 meters.
Among them, the total storage capacity of the upper reservoir reached 45.04 million cubic meters, and the total storage capacity of the lower reservoir reached 71.56 million cubic meters, and the difference between the two reached 425 meters, forming this Fengning pumped storage power station.
The so-called pumped storage power station works by pumping water from the reservoir below to the reservoir above, and then the reservoir above opens the gate and releases the water to drive the motor to rotate to generate electricity - just like an ordinary hydropower station.
In fact, it is to use electricity to pump water, and then use water to generate electricity, as we all know, there will definitely be some loss in the energy conversion process, it will definitely not be able to use 100 kilowatt-hours of electricity to pump water and then send out 100 kilowatt-hours of electricity.
In fact, the ratio of the amount of electricity required to pump water by a pumped storage power station to the amount of electricity it can generate is about 5:4, which is almost the same as using 100 kilowatt-hours of electricity to pump water and only generate 80 kilowatt-hours of electricity.
In addition, the cost of pumped storage power station is not cheap, the aforementioned Fengning pumped storage power station, its total investment reached 19.237 billion yuan.
However, I will tell you that in the next few years, China will invest much more in pumped storage power stations than we thought, and there are currently 69 pumped storage power stations under construction in the country, with a total installed capacity of 82.42 million kilowatts.
Many people may wonder why they should build it vigorously if this is a money-losing project.
Regarding this issue (pumping water from 100 kWh to generate 80 kWh of electricity), I have seen many people say that this is the operator making the difference between the peak and valley electricity prices, using the electricity at a lower price during the trough period to pump water, and then generating electricity and selling it when the electricity price is higher during the peak period.
On the face of it, it seems that this is indeed the case, and pumped storage power stations operate roughly this way, pumping water during low demand times and generating electricity during peak demand demand, but this is not the essence of the country's vigorous development of such power stations.
This is mainly due to the fact that as China shifts to clean energy, the installed capacity of renewable energy power plants such as wind and photovoltaic power plants has increased, and power generation has become difficult to control.
In modern society, we usually don't think about how many "goods" get into our hands, we only consume all of them, which is the result of the increasingly clear division of labor in society.
In fact, it is a very complicated process for electricity to be able to use it.
Figure: The link in the electrical delivery process
The world's power system is composed of power generation, transmission, transformation, distribution and use, and "generation" refers to power generation, which is composed of power stations in various forms of energy.
"Transmission" refers to power transmission, because the voltage from different power plants is different, and the voltage transmitted to different regions is also different, so the process of power transmission needs to pass through the transmission and substation first to change its voltage.
Pictured: This is a power transmission substation
In order to reduce the energy consumption loss during power transmission, no matter the length of the transmission distance, the voltage is very high after passing through the transmission and substation, so the electricity needs to pass through a distribution substation to reach the power terminal of enterprises and residents to reduce the voltage that we can use.
This is roughly the case with the power transmission of the entire power grid, which does not seem to be complicated, but in fact, the complex part of the power grid is not the link of the entire power transmission process, but the balance of power - this is to ensure that you can turn on the lights at any time and have electricity available.
Many people may not know that our electricity is instantaneous, and power plants will generate as much electricity as enterprises and residents use.
Figure: The power system must be balanced in real time
If the electricity generated is not used, the power plant will be overloaded, and the power generation equipment will accumulate too much heat and cause an accident.
Therefore, the national grid must generate electricity according to the actual electricity consumption to ensure that there will not be a situation where the power generated is not exhausted.
However, all renewable energy sources such as wind, solar, and hydro power cannot generate electricity as we want, and they all depend on the weather, and power generation fluctuates very much, so it is difficult to balance it.
You might say it's good to stop these plants when electricity is low.
This can really solve the problem of generating too much electricity when the electricity consumption is low.
However, this is the worst idea, because any power generation equipment is built with a huge amount of money, and it is impossible to stop it from generating electricity, and the operator wants it to run at full power all the time.
In fact, the best way is to store the inexhaustible electricity and use it when needed, which is the role of pumped storage power stations, which is also the relatively low-cost method of storing excess electricity at present.
The power grid allocates the excess electricity to the pumped storage power station and lets it pump water, which is actually a "power bank", but it stores the potential energy of water.
This kind of power station is not only like a power bank when storing electricity, but also the same as a power bank when it is used, when the power generation of the power grid is not enough at the peak of electricity consumption, this kind of power station begins to release water power generation as a supplement.
Chart: Renewable energy continues to increase
Due to the increase in our country's investment in renewable energy power stations in the future, the proportion of such uncontrollable energy generation will be larger and larger, so in order to ensure the balance between supply and demand of electricity, it is natural to build more pumped storage power stations.
However, pumped storage power plants are not a complete solution to the power generation problems caused by these renewable energy plants, because they are slow to respond and cannot quickly convert electricity into potential energy for water.
Of course, you can build enough pumped storage power plants to solve this problem, but the site requirements for such power plants are particularly high.
Therefore, pumped storage power stations are not the best solution, in fact, for photovoltaic and wind power, the best way to store more electricity is the battery - chemical power storage, which can quickly store excess electricity.
Although we use chemical batteries in all kinds of electrical equipment, as you can see, the development of chemical batteries is too slow and expensive, so it is still a bit difficult to rely on chemical batteries to balance the increasing installed capacity of renewable energy in our country.