The document discusses how electricity is generated at power stations using non-renewable energy sources like coal, oil, gas, and nuclear fuels. It describes the key parts of the generation process including the boiler, turbine, generator, and cooling tower. While non-renewables are relatively cheap and reliable, they will eventually run out and burning fossil fuels pollutes the atmosphere. Renewable sources like wind, tidal, wave, and hydroelectric are better long term but have high costs and disadvantages currently.