In May 2024, the efficiency of the unit TG3 generator at HPP Vranov I was measured using an indirect calorimetric method. This method is based on the measurement of all significant heat flows emitted by the generator to the surroundings, where this heat represents the energy losses of the generator.

The measurement was performed at 5 different power levels and time consuming due to the need for sufficient stabilization of heat flows before each measurement. The stabilization required approx. 3 h of constant operation at each specific power output.

The results and the shape of the efficiency curve correspond well to results of unit TG2 generator efficiency from year 1984.