News & events

2015-08-13

Heat wave not only stress out population, but also high voltage electric equipment

Throughout these two weeks of exhausting heat, the engineers and subcontractors of Litgrid, Lithuania’s electricity transmission system operator, have been facing a very particular problem – how to ensure the reliable electricity transmission in such extreme weather conditions. When the temperature rises above 30 ºC, more failures occur in the electricity transmission grid. During the last weekend only, more than 15 line failures were recorded, and only the due performance of protective equipment saved consumers from disturbances of the electricity supply.
 
“In the summer time, we face a lot of nature’s challenges, and our duty is to effectively and promptly find the best decisions in order to satisfy all consumers’ need without any inconvenience. Everyday operation of the electricity transmission system is based on the principle of compensation – if one line fails, other elements in the system must compensate for it. This ensures the safe and reliable electricity supply”, said Raimundas Tamošiūnas, Head of the Grid Maintenance Division of Litgrid. According to him, all incidents in the electricity transmission grid are recorded and fixed immediately.
 
As a result of heat, the high voltage electricity transmission wires hang down lower than usual, and an electric discharge may even occur if the overhead line passes above bushes that have grown a bit higher. If the temperature exceeds 35 ºC, all work is temporarily adjourned in transformer substations in order to keep the specialists away from the hot electrical equipment.
 
According to Mr. Tamošiūnas, the recent two weeks have been one of the hottest that even the most experienced Litgrid engineers can recall. Also, this kind of weather creates other dangerous weather phenomena, such as lightning, gusting winds, or hard pouring rain. Under such circumstances, people are urged to stay away from high voltage overhead lines, and to not stand under the wires or pylons. Under such extreme circumstances, particular care should be taken by farmers working in fields where the high voltage overhead lines pass.
 
Compared to the reliability of the other European electricity transmission grids, Lithuanian grid is well developed and operates reliably. In 2014, the grid had 10 failures that resulted in short-term local interruptions of the electricity supply.