The total annual hydropower production today amounts to somewhat
less than 64 TWh. In all there are about 1,000 hydro stations
in the system, fourteen of which have an installed capacity
of more than 200 MW. About 650 stations are smaller than 1
MW and contribute together in the order of 1 TWh per year
only.
The hydropower is highly regulated. Almost half of the hydropower
produced comes from water stored for shorter or longer periods
in the reservoirs. The production in mid winter is up to ten
times that corresponding to the natural runoff of the rivers.
