Den svenska vattenkraften

During a normal year   Swedish hydro power produces 64 TWh of electricity. During a dry year the production can decrease to 50 TWh, during a wet year it can increase to 75TWh.
Hydro power produces almost half the total electricity supply in Sweden and 15% of the total energy supply. As hydro electric production is cheap, Sweden has one of the lowest energy prices in the world.
It would be economically justifiable to build out the hydro power with further 30 TWh, but the Swedish Parliament has decided to stop further extension. However construction of enviroment adapted small scale power plants (0,1 - 1,5 MW) will be stimulated..
Magasinering The discharge in the regulated rivers is not the same during the whole year. In winters the rain is bound as snow and the water flow is small. In spring the snow melts and the water flow becomes several times bigger than during the rest of the year. It is not profitable to build a great number of turbines for using all the water during the comparatively short   spring flood period.The degree of utililization of the theoretically available   hydro power is a compromize based on energy prices, total project economy, construction costs and enviromental considerations.

The power consumpperiodtion is largest in the winter and lowest during the general industry holiday in summer.
If more hydro power plants were built, the overproduction of electrical power should be even larger than today To use the surplus energy would be impossible as as it is not possible to store larger amounts of electric energy for future needs. The only possibility to store energy in our power system is to save the water in the water reservoirs in our rivers. The reservoirs will be filled up during the spring flood and tapped out during winter when the need is greatest.
 
There are also several years' reservoirs, where water from dry years is stored and used during years with lack of water.
The biggest water reservoirs in Sweden are Vänern (Göta Älv) and Sourvadammen (Lule Älv). If the surface of Vänern is lowered 1 cm, the obtained energy would be enough for the annual consumption of electricity of abt 350 electrically heated houses!


Kvaerner Turbin