**1. Introduction**

122 Renewable Energy – Trends and Applications

[31] STN EN 61400-12 (333160): 2001. *Wind Power Plants. Part 12: Power of Wind Power Plants* 

[30] http://www.wasp.dk/, 2. 6. 2008.

*Measurements.*

The world economy is the key driver for global primary energy consumption. According to the economic recovery in 2010, the world primary energy consumption is rebounded which was accounted for 12,002.4 Mtoe, increased by 28 % from year 1998 (BP, 2010). The important primary energy sources are fossil fuels, e.g. crude oil, natural gas, coal, whereas the renewable energy source has a small share. If the world population, world economy and consequently the world energy consumption are still growing rapidly, in spite of there are more than 1,000 thousands million barrel proved oil reserved in 2010 (BP, 2010), the world will face to problem of oil price crisis and also oil diminishment in the near future. Beyond that crisis, the utilization of fossil fuel will lead to an increase in carbon dioxide emission in the atmosphere. In 2007, global carbon dioxide emission was accounted for 29.7 billion metric ton (U.S. Energy Information Administration [US IEA], 2010), increased approximately 1.7 % from previous year (29.2 billion metric ton in 2006 (US IEA, 2006)) and it was predicted that the concentration of carbon dioxide still increases by an average of 0.1 % annually for OECD countries and an average of 2.0 % per year for non-OECD countries until 2035 (US IEA, 2010). The high concentration of carbon dioxide causes the greenhouse effect and consequently, the global warming which becomes the serious problem to human race.

Nowadays there are many efforts to reduce both the use of fossil fuel and the carbon dioxide emission by using renewable energy as a substitute to fossil fuel. This renewable energy includes solar energy, wind energy, hydro energy as well as energy derived from biomass, tide and geothermal. These renewable energy sources can be used not only for heat and power generation but also for liquid transportation fuel production. During four consecutive years from end-2004 to end-2008, the global solar photovoltaic had increased six-fold to more than 16 GWe, while the global wind power generation had risen by 250 % to 121 GWe. More than 280 GWe had been produced from hydro, geothermal and biomass power plants which increased 75 % from the last four year. In the same time interval, the heat production from solar heating was also doubled to 145 GWth. In the perspective of biofuel production, biodiesel production increased six-fold to 12 billion liters per year, whereas ethanol production was doubled to 67 billion liters per year (Renewable Energy Policy Network for the 21st Century [REN21], 2009).

Analogy to global energy situation, Thailand has faced to the problem of energy crisis, especially oil price crisis. Thailand has been relying on fossil fuel as the primary source of energy which has to be imported from foreign countries, and simultaneously Thailand energy consumption has been increased rapidly and continuously. This chapter will focus on the energy situation in Thailand, the energy policy plan and finally the possibility of using renewable energy sources as alternative energy to energy from fossil fuel.
