Seite - 40 - in Our Car as Power Plant

40 We need to produce electricity at the moment we need it. Demand and supply have to be in balance at every moment in time. The demand for electricity is not constant. During the day we need more electricity at our offices, schools, industry and for all kinds of appliances. In winter we need more electricity for lighting than in summer. But in summer we need more electricity for air-conditioning, as in winter for heating. And when there are special events, for example an important football match, we all watch television and there is a peak in demand. How can the supply of electricity deal with these variations? It can be done in several ways. We can for example store electricity by pumping up water to a higher basin. When we need electricity, the water is falling down through a hydro turbine that generates electricity. We can also ask clients to use less electricity and in return they get a better price. This is called load management. Many processes can handle some flexibility, for example our refrigerators. But at the moment, fossil-fired power plants are by far the dominant system to regulate supply of electricity. POWER SYSTEM EFFICIENCY