Hydro power is an important source of energy, accounting for over 40 per cent of Sweden’s total energy production. Thanks to its controllability, hydro power helps to keep the price and availability of energy at a stable level.
As Sweden’s biggest source of renewable energy, hydro power currently accounts for about 40 per cent of the overall energy mix. We have a relatively plentiful supply of water, and large reservoirs allow the water to be stored and used for production at times of peak demand. Hydro power converts the potential energy of rainwater and meltwater into electricity. In total, there are over 2 000 hydro power stations in Sweden. Of these, just over 200 are larger, with an output of 10 MW or more.
Building a hydro power station requires a substantial initial investment, but both the technical and the economic lifetime of the station are long. Hydro power has no fuel costs and Sweden has a plentiful and stable supply of water. What is more, hydro power can be controlled in response to demand. This is what makes hydro power a relatively safe investment.
Production at a hydro power station depends entirely on the local landscape, particularly the size of the river in question and the head of water that is available. When the hydro power stations were built, the dams, turbines and generators were tailored to these natural conditions, which is why their size and capacity varies. In a normal year, Holmen Energi’s hydro power stations produce around 1 100 GWh combined, but individual output ranges from about 10 to 500 GWh.
During production, a hydro power station has no direct impact on the climate. The effect comes instead from the manufacture of the materials required to build the power station. Stretched out over the lifetime of the hydro power station, however, the impact on the climate is minimal compared with the effects caused by fossil-based energy production.
Hydro power is essential if we are to maintain a secure and reliable electricity system, not least because of its renewable and fossil-free electricity production, plus the unique ability to adapt production to society’s needs. However hydro power can effect the immediate environment and the biodiversity in the rivers along which the power stations are built. Plants and animals that depend on fast flowing water are restricted and fish species that need to migrate between rivers, lakes and the sea are affected.
In a move to weigh the positive benefits of hydro power, particularly its importance within the national energy mix, against its environmental impact, the Swedish parliament has decided that all hydro power must be subject to modern environmental conditions. A key environmental factor in the upcoming review will be the maintenance of efficient hydro power production at system level.
A hydro power plant always brings a certain amount of change to the look of the landscape. The question of whether the changes are positive or negative depends entirely on your perspective.