Ljubljana - Slovenia will have to step up the use of renewable energy sources in the coming years if it is to hit EU green transition targets. Investments are, however, often hampered as energy interests collide with environmental concerns, and the power grid is far from robust enough to bring significant renewable sources online.

The EU has placed a long bet on renewable energy sources as a way to mitigate climate change, an endeavour that has gained a renewed sense of urgency with the Russian invasion of Ukraine and Europe's resulting pledge to wean itself off Russian energy.

As countries phase out Russian gas, electricity consumption is projected to rise substantially, according to Vekoslav Korošec, the director of the Engineering Association at the Chamber of Commerce and Industry (GZS).

He told a debate recently that siting of major energy projects had to be accelerated fast, which has to be coupled with intensive construction of infrastructure for the use of hydro, solar, biomass and geothermal energy.

Slovenia reached the EU renewables target last year, but did so using a statistical method. While the share of renewables in final gross energy consumption was 24.1%, it bought the missing portion to reach 25% from a fellow EU member state.

Due to the abundance of forests, the biggest source of renewables in the country is wood biomass, which is still widely used for heating, especially in rural areas, where 30% of households use wood to heat homes, according to Slovenia Forest Service data.

However, household furnaces are often outdated and poorly maintained, producing high levels of particulate emissions.

Hydro is also well developed, but exploitation is nearing the theoretical limit. Most major rivers are either fully exploited or enjoy a degree of nature protection and are hence off-limit to development.

A concession agreement has been signed to build several more hydro plants on the central Sava river, downstream from Ljubljana, but recent experience with new hydro plants on the lower Sava shows siting is torturous and often hampered by environmentalists due to concerns over biodiversity.

The last of the remaining plants on the lower Sava, Mokrice, has been held up for years over its impact on native fish populations.

Wind energy is already a major source in Europe, covering for about 16% of all energy, but in Slovenia there is a sole large wind turbine.

Several major projects have been abandoned over the years due to opposition by locals and environmentalists. A few projects are planned, but like hydro plants, wind projects are beset by siting and permitting delays.

A lot of hope is being placed on solar, which has been rapidly expanding, albeit from a low base; wind and solar combined accounted for roughly 2.2% of electricity production in 2020.

With electricity prices surging, the demand for small photovoltaic plants has surged, not least due to the availability of subsidies, but problems soon emerged with the capacity of the power grid.

SODO, the distribution system operator, told the STA that there were so many requests for connecting small solar plants that the grid, designed for centralised rather than distributed generation, was close to capacity.

It said small solar plants may not be the best option for Slovenia, instead, the country should focus on "exploiting the existing grid by placing generation capacity at locations where the existing grid allows it."

They said a consensus by all stakeholders was needed to define what was best for the country in the process of green transition.