Ljubljana's district heating will soon get more environment-friendly as the capital city's combined heat and power plant has begun trial operation of a new gas-steam unit.

Once it becomes fully operational, the €145 million unit will allow Termoelektrarna-Toplarna Ljubljana (TE-TOL) to reduce the use of coal by 70% and double electricity production.

The utility operating the plant, Energetika Ljubljana, expects the trial operation to run for nine months. The electricity and heat generated during this period will be fed into the grid.

After the unit is launched, natural gas will become the primary fuel. The remaining coal will continue to be used in Unit 3, where it is combined with wood chips.

While continuing to supply the necessary amount of heat for Ljubljana's district heating system, the plant will double electricity production for Slovenia's power grid.

Currently, the plant produces 1,100 gigawatt-hours (GWh) of heat and 400 GWh of electricity annually. In the future, it will maintain the required heat output but increase electricity production to 800 GWh.

This will make Energetika Ljubljana, with an 8% share, the third-largest electricity producer in the country, behind HSE and Gen Energija.

Energetika Ljubljana does not anticipate any adjustments in prices yet. Pricing will be determined after the new unit becomes operational, as not all reference conditions are known at this time.

"However, it is worth noting that we will continue striving to remain one of the most affordable heat suppliers of district heating," the company said on 17 October.

Located in the Moste borough in east Ljubljana, TE-TOL is the largest combined heat and power plant in Slovenia. Along with a smaller unit in the Šiška borough it provides district heating to almost half of flats in Ljubljana.