Today, it is generally accepted that electricity is a major factor in driving a nation’s economy and improving people’s living. Given the continuous economic growth of Thailand in the past 30 years, the country’s annual electricity demand has greatly increased from 14,000 million units or gigawatt-hour GWh to 150,000 GWh at present, or at an average annual growth rate of 8.2 per cent.Electricity demand has increased sharply in the industrial sector as a result of the policy of successive governments trying to scale up investment in the industrial sector.
In addition, Thailands economic development has resulted in growing electricity consumption by the commercial and residential sectors driven by higher income levels of consumers whose consumption characteristics have shifted towards greater convenience and modernization. A greater number of electrical appliances are thus widely used, for example, refrigerators, electric fans, rice cookers, televisions, light bulbs, including air-conditioners, computers, and so on.
These appliances have become necessities in Thai households. As electricity becomes a major factor in the countrys economic development and peoples living, energy development plans have so far focused on expansion of electrification to ensure adequate and extensive service coverage.Consequently, the government has to work out the power development plan of the country to increase the generating capacity of the system so as to adequately meet the rising demand. In 1979, the peak demand of power was 2,964 megawatts MW while that in 2009 amounted to 22,596 MW.
Meanwhile, power transmission and distribution systems have been so much expanded, particularly in the service areas of the Provincial Electricity Authority PEA, that they can presently cover almost all areas nationwide. However, the planning of power generating capacity expansion is a complex matter because related factors under various conditions and policy guidelines are involved, for instance: