How Long Would Power Plants Last Without Humans?

In the grand scheme of modern civilization, power plants are the lifeblood that keeps our societies functioning. From nuclear reactors to hydroelectric dams, geothermal facilities, wind turbines, and solar farms, these installations tirelessly generate the electricity that powers our homes, industries, and technologies. But what would happen if humans suddenly vanished from the picture? How long could these intricate systems continue to operate without our intervention?