The Three Gorges Dam can generate 197.1 billion kWh each year, so why can’t it operate at full capacity every day?
The Three Gorges Dam is the largest hydroelectric dam in the world.
According to information released by the Three Gorges Power Plant of the Yangtze River, at 12:22 AM on August 30, 2021, under conditions ensuring flood prevention safety, all 34 turbines of the Three Gorges Dam operated simultaneously, connecting to the power grid with a total production of 22.5 million kWh, marking the first time it operated at full capacity in 2021.
We all know the Three Gorges Dam is the largest hydroelectric dam in the world and a source of pride for China, but why had it never operated at full capacity before? Is it due to an inability to do so or concerns about something?
How much electricity can the Three Gorges Dam produce?
According to the China Three Gorges Corporation, as of 12 AM on December 31, 2020, the Three Gorges Hydropower Station had accumulated a total electricity production of 111.8 billion kWh for the entire year.
This figure not only became the highest record for electricity production in the history of the Three Gorges Dam, but it also broke the world record of 103.098 billion kWh set by the Itaipu Dam (a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay).
What does this electricity production figure mean?
The Three Gorges Dam generated a profit of 27.95-33.54 billion RMB in 2020.
The market value of electricity from hydroelectric dams typically ranges from 0.25 to 0.3 RMB/kWh (over 860-1,000 VND). Therefore, the Three Gorges Dam generated profits of 27.95-33.54 billion RMB (96.3-115.5 trillion VND) in 2020.
If we calculate based on the annual electricity consumption of a family of three at 1,000 kWh, the electricity generated by the Three Gorges Dam in 2021 could supply 335.4 million families for an entire year.
Moreover, since the demand for electricity is fixed, hydropower plants must produce more, while coal-fired power plants reduce their output accordingly. This allows China to save a significant amount of coal resources.
It is estimated that in 2020, the total electricity production of the Three Gorges Dam was equivalent to the electricity generated by burning 34 billion tons of standard coal from thermal power plants. Furthermore, burning such a massive amount of coal would produce 94.02 billion tons of carbon dioxide (CO2), 21.2 thousand tons of nitrogen oxides (N2O), and 22.4 thousand tons of sulfur dioxide (SO2).
The Three Gorges Dam has a total of 32 generators of 700,000 kWh and two generators of 50,000 kWh.
It can also be said that due to the existence of the Three Gorges Dam, China has saved coal resources while reducing the amount of harmful gases released into the environment. From a certain perspective, the construction of the Three Gorges Dam was a “win-win” move.
However, despite the record electricity production of the Three Gorges Dam in 2020, it is still not the best figure when compared to the scale of the largest dam in the world. Why is that?
Reasons the Three Gorges Dam Cannot Operate at Full Capacity
As the largest hydroelectric plant in the world, the Three Gorges Dam has a total of 32 generators of 700,000 kWh and two generators of 50,000 kWh, with an installed capacity of up to 22.5 million kWh.
If all the generators are operational, the Three Gorges Dam can produce 6,250 kWh every second and 540 million kWh in one day. Ultimately, the electricity production in one year could reach up to 197.1 billion kWh, equivalent to the annual electricity consumption of 5.4 million households.
Yet, the Three Gorges Dam can generate 197.1 billion kWh each year, so why can’t it operate at full capacity every day?
This is related to China’s primary goal in constructing the Three Gorges Dam, which is flood control, not electricity generation.
Additionally, the Three Gorges Dam also undertakes other tasks such as cargo transportation, irrigation, and regulating the water flow of the river. These tasks consume the initial water resources that would have been used for power generation. Therefore, the generators of the Three Gorges Dam will not operate at full capacity under normal circumstances.
The 111.8 billion kWh of electricity generated by the Three Gorges Dam in 2020 was the maximum production achievable while balancing the tasks of flood control, cargo transportation, and water resource utilization.
Furthermore, to achieve maximum operational capacity, the water level of the Three Gorges must reach a certain height.
The Three Gorges Hydropower Plant can generate 197.1 billion kWh each year.
During the flood season of the Yangtze River in 2021, due to continuous rainfall in the upstream area, at 12 AM on August 30, the water level in front of the Three Gorges Dam rose to 154.45 meters, meeting the requirements for the full operation of all 34 turbines.
Therefore, with the strong support and cooperation of the Yangtze River Water Conservancy Committee, the State Grid Corporation of China, the China Southern Power Grid, and other units, the Three Gorges Power Plant achieved its first full capacity operation, ensuring safety for residents along both banks of the river and the surrounding infrastructure.
