Lenenergo’s system was comprised of 20 entities in 1941, including six thermal power plants, three hydroelectric plants, as well as networking and maintenance facilities with a total capacity of 758.5 MW and energy output of more than 30 million kWh. Lenenergo suffered significant damages during World War II and lost two thirds of its power system capacity. Leningrad was taken under siege on September 8, 1941. However, thanks in no small part to the selfless labor and courage of Leningrad’s power engineers, the city withstood the blockade.