Hydropower

Photo: Tyler Olson_Dreamstime.

In Norway we produce 80% of our electric power with the help of water energy. This is a renewable resource, and it does not pollute the environment.

The sun and gravity are the driving forces in the circular flow of water. Solar power makes the water in the seas and lakes evaporate. When the evaporated water cools down, the water falls in the form or rain or snow. There is a lot of precipitation in Norway, especially on the west coast. Here there are also steep mountains, and water flows down towards the sea. Waterfalls are channelled into pipelines. The amount of water and the length of the fall determine how much energy can be obtained from a body of water.

Electricity cannot be stored in very large quantities, and in order to produce enough electric power throughout the year, we build dams to collect water from bodies of water. In the spring, when the snow melts, there is a lot of water in lakes and rivers, and these dams, called impoundment dams, are filled. During the winter, when we use a lot of electricity, we use the water reserves in the dams. In this way we can produce electricity even if there is no precipitation.

The water is led from the dam through pipelines or tunnels to the hydroelectric plant. There the flowing water is pushed through blades that turn a turbine around. Thick coils of copper wire are mounted on the shaft in the middle of the turbine. When the copper wire rotates in a magnetic field, electricity is produced. This occurs in what we call a generator.

The electricity goes from the generator to a transformer, and out to the supply mains. In order to ensure that the least amount of energy possible is lost while being transported from the power station to the consumer, the electric tension is transformed while being transported. In the distribution substation near the consumers, the electricity is transformed to 220V so it can be used in households.

Click on the link from Statkraft for more information about Hydropower.