As industry revived and began to expand after World War II, the need for electricity grew. The supply was limited and unreliable, and some industrial firms and businesses installed their own generators, mostly fueled by imported oil. In 1958 the Metropolitan Electricity Authority (MEA) was established to generate and supply power to Bangkok and adjacent provinces. A year earlier the government had also set up the Yanhee Electricity Authority (renamed in 1969 the Electricity Generating Authority of Thailand--EGAT) to promote development of hydroelectric power. The first hydroelectric generating facility was the Phumiphon Dam. Completed in 1964 on the Mae Nam Ping, it had an installed capacity of 420 megawatts in 1979 and a potential of 560 megawatts.
Escalating power demand led to construction of a major oil-fired plant, the North Bangkok Power Station, which went into operation in 1961. Installed capacity from 1968 totaled 237 megawatts. The capital area became adequately supplied with the construction of a new oil-fired plant in Bangkok. The South Bangkok Thermal Power Plant started up in late 1970 with a 200- megawatt capacity; by 1977 this was increased to 1,300 megawatts. The country’s second major hydroelectric plant, at the Sirikit Dam (potential generating capacity of 500 megawatts) on the Mae Nam Nan, a major tributary of the Chao Phraya, started generation with an installed capacity of 375 megawatts in 1974. A third large hydroelectric facility, part of a multipurpose irrigation, flood control, and power project at Ban Pho on the Mae Nam Mae Klong northwest of Kanchanaburi, was completed in the 1980s with an initial capacity of 360 megawatts and an estimated potential of 720 megawatts.
Generating capacity to other parts of Thailand was on a much smaller and regionally unequal scale. Increased oil prices in the 1970s stimulated a new interest in lignite, and a lignite-fueled plant installed at Mae Mo, the site of a major lignite deposit, was producing 825 megawatts by 1987. Lignite reserves were estimated to be 865 million tons in 1985.
In the South a lignite-fired plant at Krabi with an installed capacity of sixty megawatts commenced generation in 1964. A major purpose of this plant was to furnish power for tin mines in the area and the tin smelter on Phuket Island, in addition to meeting local needs. In 1968 additional generating capacity was installed on Phuket through a ten- megawatt-capacity diesel plant, and between 1971 and 1977 three gas turbine units totaling forty-five megawatts were installed on Hat Yai. In the late 1970s, three additional gas turbine units having a combined capacity of fortyfive megawatts were also located at Surat Thani.
Development of power facilities in the Northeast received little attention until the mid-1960s, at which time the region had an estimated generating capacity provided by small diesel units of perhaps one megawatt. By the early 1970s, however, four hydroelectric plants had been installed at dams in different parts of the region, with an installed capacity of ninety-five megawatts. New gas turbines furnished an additional thirty megawatts, and diesel units produced an additional four megawatts.
In 1987 the power sector was composed of three governmentowned enterprises: EGAT, under the Office of the Prime Minister, was the national power production agency; MEA, under the Ministry of Interior had responsibility for power distribution in Bangkok and the provinces immediately around the city; and the Provincial Electricity Authority (PEA), also under the Ministry of Interior, distributed power throughout the rest of the country. There were also a number of privately held distribution franchises that bought power from PEA or EGAT. Some privately owned industries also generated their own power. Installed generating capacity in 1986 was 7,570 megawatts, of which 70 percent was thermal and 30 percent hydropower. In 1985 industry used nearly 50 percent of the 20 million megawatt-hours of energy consumed. Residential consumption was 25 percent, commercial establishments used 25 percent, and street lighting and miscellaneous uses accounted for less than 1 percent. By the end of 1986, nearly 43,000 villages of the more than 48,000 throughout the country had been supplied with power. It was projected that 95 percent of all villages would have electricity by 1991 and essentially all villages by 1999.