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Porjus

Porjus hydro power station
Porjus power plant is situated on the Stora Luleälv river in the municipality of Jokkmokk. When Porjus was built in the early 1900s, its purpose was to supply electricity to the Malmbanan railway line, which was used to transport iron ore. The new hydro power plant and the electrification of the railway triggered strong growth in Sweden's mining industry. Today, Porjus is the third largest hydro power plant in Sweden.

Start of Sweden's hydro power industry

In 1910, Sweden’s first hydro power plant, Olidan, which is situated on the Göta Älv river, started supplying power to industry and the railway. This paved the way for the development of the Luleälv river and the construction of Porjus power plant. Until that time, people had been very sceptical about electricity. It was not until the problems associated with transporting electricity over long distances without major losses were solved that interest in electricity increased. 

Work on the construction of Porjus power plant started in 1910, at a time when there was no road or railway access to Porjus. Both construction itself and transportation of the necessary materials was extremely difficult, because materials and other supplies had to be transported 50 kilometres from the nearest town, Gällivare. In the first few months, five tonnes of materials and supplies were carried on foot across the wilderness to Porjus on makeshift paths. Fortunately, this arduous and time-consuming work came to an end in 1911 when the railway line from Gällivare to Porjus was completed.

In 1915, King Gustaf V officially declared Porjus power plant open by telephone because his advisers deemed it unsafe to undertake such a long journey during war time. Porjus quickly became a hub in an industrial Sweden which was consuming ever more energy. When the power plant was officially opened, there were already 20 hydro power plants all over Sweden, but Porjus attracted a great deal of attention, due to its location and its construction technology, which was highly advanced for its day.

The power plant is located below ground, on a site blasted out of the rock. Between 1920 and 1960, the number of turbines in the old power plant increased to nine units. The turbines still function but are not used for normal operations. Two of the old units have been converted into research units and are used to test new technology and equipment.

New power plant

A new power plant with two new units was built between 1971 and 1975. The new power plant has a total capacity of 465 MW and generates more than ten times as much electricity as the old plant.

All the new transformers were built below ground, so a new building was not required. The old building, however, remains as an impressive monument and visitor centre. The old dam has been replaced with a stone-filled dam with an impervious core of moraine. It was built immediately downstream of the old dam, and has two new spillways which are closed using segment gates.

About hydro power and the Luleälv river

Hydro power is a reliable, safe and renewable source of energy. Almost half of Sweden's total electricity requirement is currently supplied by hydro power. The Luleälv river, on which Porjus is situated, is Vattenfall's and Sweden's most important river in terms of hydro power generation.  Hydro power will be an important source of renewable energy in the future too. Vattenfall is currently implementing major investment programmes at its hydro power plants in order to increase capacity and reinforce the dams with a view to generating more electricity and improving safety.