Whether wind and photovoltaic power can ultimately replace coal-fired and natural gas power generation depends on two key nodes, or rather critical points:
(1) New vs. New

The first critical point is that, without subsidies, the cost of building new wind and photovoltaic power stations can compete with that of building new coal-fired and natural gas power stations. Under current market conditions, many countries are approaching this critical point. In Germany, the cost of building onshore wind power is already lower than that of coal-fired and natural gas power generation; In China, the current cost of coal-fired power is still the lowest among all types of power sources, but it is expected that the cost of onshore wind power will be lower than that of coal-fired power in 2019, and the cost of photovoltaic power will also be lower than that of coal-fired power in 2021; In the United States, natural gas power generation has the lowest cost among all types of power sources, but it is expected that the cost of wind and solar power will be lower than that of natural gas power generation from 2022 to 2023; In India, it is expected that new photovoltaics will be lower than coal-fired power nationwide starting from 2020.

(2) New vs. Old
The second critical point is that the power generation cost of newly built wind and photovoltaic power stations is lower than the operating cost of existing coal-fired and natural gas power stations. This critical point will arrive faster than people imagine. In China, it is expected that the cost of photovoltaics will be lower than the existing operating cost of coal-fired power by 2030; In the United States, the cost of photovoltaics will be lower than the operating costs of existing natural gas power plants starting from 2027; In Germany, the cost of onshore wind and solar power will be lower than the operating cost of coal-fired and natural gas power plants between 2027 and 2030.
According to BNEF's prediction, solar photovoltaics will become one of the dominant energy sources by 2040, accounting for 32% of the world's total installed power generation; Wind power accounts for 14%, hydropower accounts for 12%, coal-fired power accounts for 14%, natural gas accounts for 13%, and nuclear power accounts for 3%.