Based on current price levels of various power generation equipment and fuels, coal-fired power generation remains the cheapest. On the surface, hydropower seems to have low operating costs, but the construction period of a hydropower plant takes several times longer, and the unit cost is about twice as high as that of a conventional thermal power plant ( the cost of thermal energy per kilowatt is only about 5,000 yuan), but the effective electricity generation time per year is (3,000 hours), but only about half of that of thermal energy (6,000 to 7,000 hours of thermal energy). Therefore, based on various factors, coal-fired power generation has the lowest overall cost and is the most reliable.
Solar and wind power generation also have problems such as high cost, short operating time,intermittent power generation and unreliability.
Nuclear energy is also expensive. And China is running out of nuclear fuel.