The administration of the mercury mine in Idrija put a Francis turbine hydro power plant into operation, which was used for the electrification of the main mining plant.
On the Hubelj River in Ajdovščina two power plants with a Francis turbine were built. The first was designed for the copper processing and the production of copper products, the other, however, was erected in the textile factory.
The Commune of Idrija engaged Josip Kogovšek, the owner of the mill and sawmill on the Idrijca River, to carry out the electrification of the whole town. The Kogovšek power plant was in operation up to the year 1933 when an Italian company took over the power supply of the town of Idrija.
The administration of the Idrija mine built the Pečnik hydro power plant on the stream Peklenski potok into which a Pelton turbine was built in. The power plant terminated its operation in the year 1971. The company Soške elektrarne in the year 1983 then reconditioned and reopened it. Electrical energy is still produced in it.
For the necessities of the mine also the Idrija hydro power plant – city was built. Due to the low water affluence it was first meant as power plant combined with diesel motors. Later on many times buildings were added. The power plant is still in operation. Water is supplied from 400-year old water channels – the so-called “rake”.
For the necessitites of the city and its outskirts in Kobarid the Francis turbine power plant 'Pri treh mlinih' was built. The power plant was in operation up to the year 1930, when the Italians incorporated the town of Kobarid and its outskirts in their transmission line.