“Energy Conservation” in this Energy Efficiency Development Plan has two meanings: (1) economical use or reduced expendable use of energy, and (2) energy efficiency improvement, i.e. doing the same activities with less energy, involving, among others, lighting, hot water production, cooling systems, transportation or running machines in the manufacturing process. Energy conservation plays an important role in strengthening energy security, alleviating household expenditure, reducing production and services costs, reducing trade deficit and increasing the competitive edge, including reduction of pollution and greenhouse gases (GHG) which cause global warming and climate change. Therefore, energy conservation has been an important policy of the government, particularly since the enforcement of the Energy Conservation Promotion Act, B.E. 2535 (1992). Five-year plans to allocate funding support from the Energy Conservation Promotion Fund for energy conservation activities have been consecutively developed, now being in Phase 3. Nevertheless, the government has foreseen that problems with energy prices, international competition for energy resources, environmental impact and climate change resulting from energy production and utilization will be exacerbated in the future, which will inevitably affect people’s well-being and the national economic competitive edge. In addition, at the Asia-Pacific Economic Cooperation (APEC) Summit in 2007, government leaders ratified the collaboration in energy conservation promotion to meet the agreed target in 2030. In response to this, the Ministry of Energy has developed this 20-year Energy Efficiency Development Plan (2011-2030) to provide the national policy framework and guidelines on energy conservation implementation in the long term, with the following two main