kernenergien | solar sutainable strategy

Hydropower

Sunlight is heating up the oceans, lakes and rivers of the world. Water evaporates and rises into the atmosphere. Under special circumstances the water will condensate and fall down to earth as rain. It fills up lakes and rivers again. This is called the atmospheric water cycle.

If the rain falls down on mountains, it will gain kinetic energy by flowing towards the ocean. This energy can be converted into electricity by water power plants. The flowing water causes a turbine to rotate, which moves a generator to generate electricity. The power plants are distinguished by run-of-river and storage power plants.

To use the constant flow in a run-of-river power station, rivers are dammed up. In order to store the water flow for times when energy is needed, reservoirs are build. This way peak load can be produced instead of base load in run-of-river power stations. Already today 17% of the world wide electricity demand is served by water power. But the potential is not tapped at all. Especially for smaller power plants there are far more possibilities than those already used. The power of a small-scale water power plant goes up to several kW, while large-scale power plants reach up to several hundred MW.

The picture shows the energy density of water power in Europe. Further basic Information can be found on Wikipedia.