The main objective of actual energy policies around the world is the transition to renewable energy. EIA forecasts nearly 50% increase in world energy usage by 2050, which is hard to achieve using only renewable energy. For year 2019 the electricity production in EU relies mainly on conventional thermal (42.8 %) and nuclear energy sources (26.7%). The accelerated transition to electrical cars puts more pressure on energy producers. As a result, in order to match the ever-growing demand of electrical energy, the conventional thermal energy generation will play a key role, among them coal-based production. In order to meet the environmental goals and for sustainable production of electrical power, energy assessment of power production of coal-based power plants must be performed. The purpose of this paper is to perform an energy assessment of the electrical power production, focusing on a key component of this, the steam turbine. The performance characteristics of the turbine in condensing operation were determined. A proper efficiency of the turbine will have a significant impact on sustainable production of electricity.

In mine air conditioning systems, the vapour compression refrigeration cycle seems to be currently the most widespread method of artificial cooling. In literature some other methods for cooling a mine are also presented, like using free-cooling in refrigeration systems. Mine workings in Jiu Valley are using the primary and secondary ventilation system for cooling the underground. Today the activities are focused mainly on mine closure as a part of transition to the low carbon economy, and this situation brings new challenges regarding the mine ventilation system, which was designed to meet the needs of a full-scale operation. As a result, locally ambient temperatures can rise, and spot cooling systems can be used, in order to cool the air. Such a system has been considered and calculations have been made to evaluate its thermal efficiency at different ambient temperatures.