Bulgaria's consistent emphasis on developing heavy industry at any cost created raw material demands well beyond the country's domestic resources. This problem was compounded by the inefficient industrial use of energy and raw materials: Bulgaria used more energy per unit of NMP than any Western economy. For this reason, one of the most salient aspects of the Bulgarian postwar economy was reliance on imported Soviet natural resources.

Fuels

In 1989 Soviet imports supplied Bulgaria with 95 percent of its coal, 90 percent of its crude oil, and 100 percent of its natural gas. Although Bulgaria imported the majority of its raw materials for energy and industrial requirements, some domestic fuels and minerals were available. A small supply of hard coal was depleted rapidly in the 1980s in 1987 only 198,000 tons were mined. More ample deposits of low-quality lignite yielded 31,400,000 tons in 1987, but those fuels were relatively inefficient energy producers and high polluters. In 1990 the Maritsa Basin in south-central Bulgaria was expected to remain the prime source of lignite for the foreseeable future yearly production at its Maritsa-iztok open-pit mines was projected to reach forty million tons after the year 2000.

Data as of June 1992