The only oil-fired thermal plant is at Unggi, near the Russian border. The 200-megawatt plant receives its fuel oil from the nearby Unggi refinery, which uses crude petroleum imported from Russia. Construction for the station began in 1968 with Soviet support and was completed in December of 1977, according to the terms of the North Korean-Soviet Economic and Technology Agreement signed in March, 1967. It is the main energy source for industrial facilities in the Northern regions of North Hamkyung province like the Victory Chemical Works and Kim Chaek steel mill. There are no domestic oil reserves.
Oil is imported from China and the Soviet Union by pipeline, and from Iran by sea.
The quantity of oil imported to North Korea amounted to an annual average of 2.6 million tons in the mid-80s, but was suddenly reduced to 1.5 million tons due to interruption of oil import from former Soviet Union in the 90s. Because both Russia and China have insisted on hard currency payments at international prices for oil since 1991, Iran became the major oil source under a 1989 agreement to supply 40,000 barrels of oil per day. With the exception of the heavy fuel oil being provided under the nuclear agreement, most petroleum is imported as crude oil and processed at domestic refineries. Total annual refinery capacity is estimated at 3.5 to 4.5 million tons. Seungri Chemical factory in the Najin-Sunbong Area is North Korea's largest oil refinery.