Thermal power plants and nuclear power plants generate electricity through different processes. Thermal power plants burn fossil fuels like coal, natural gas, or oil to produce heat and generate steam, which turns turbines connected to generators. Nuclear power plants harness nuclear reactions to produce heat and steam without burning fossil fuels. The document also discusses renewable energy power plants, how all power plants work by converting heat into mechanical energy and then electricity, their varying environmental impacts, and future trends toward more efficient and environmentally friendly operations.