How does the fuel in your car get used based on demand? In all seriousness, there are many types of power plants, the exact mechanism depends on how the actual

How does the fuel in your car get used based on demand? In all seriousness, there are many types of power plants, the exact mechanism depends on how the actual energy is produced. It is true that for some renewable energy sources like e.g. solar energy, you cannot regulate production and need to store excess energy. But for fossil fuels, you (roughly) produce by demand.