The government expects the increase in the contribution should not be felt fully since some other contributions have been lowered, including the power grid costs.

However, glass maker Steklarna Rogaška estimates the renewables contribution could cost the company around EUR 80,000 more, which effectively means an almost EUR 54,000 higher energy bill with an estimated EUR 27,000 cut in grid costs.

Glass maker Steklarna Hrastnik meanwhile said that in case the contribution is more than tripled the costs could go up by around EUR 132,000.

Pharma company Krka technical director Marko Lampre told the STA that a 300% rise in the contribution would increase the company's total energy bill by around 13%.

The paper industry is also among the big energy users and Vipap Videm Krško expects additional costs to exceed EUR 0.5m annually.

The paper maker told the STA this would drive the company to even more austerity with the already difficult situation. The cuts will be biggest in investments and R&D, while lay-offs will only be used as a last resort, the company said.

Household appliance maker Gorenje assessed the energy costs would increase by some 2%. However, if the money collected in the contributions returns to the economy in form of incentives, the hike could be positive, the company commented.

Shortly after the rise was decided on, the Chamber of Commerce and Industry (GZS) pointed out that they believe the increase would be harmful for Slovenian companies.

The energy costs in the paper making sector alone are to increase by EUR 2.34m, according to calculations by the GZS.

The chamber also stressed that the 392% rise for steel maker Acroni from Jesenice would increase the costs by over EUR 2m, while Štore Steel will have to pay around EUR 1m more for the contribution.