Apparent wind that measures wind speed in knots and wind direction in degrees relative to the heading of the boat. Modern instrumentation can calculate the true wind velocity when the apparent wind and boat speed and direction are input. In sailboat racing, and especially in speed sailing, apparent wind is a vital factor, when determining the points of sail a sailboat can effectively travel in. A vessel traveling at increasing speed relative to the "prevailing wind" will encounter the wind driving the sail at a decreasing angle and increasing velocity. Eventually, the increased drag and diminished degree of efficiency of a sail
Wind power in Thailand energy by developing renewable energy sources in Thailand, including wind power. The first study of Thai wind energy potential was conducted in 1975 by the Department of Energy Development and Promotion, which is now called the Department of Alternative Energy Development and Efficiency (DEDE). Data of mean wind speed from the Thai Meteorological Department (TMD) was used to produce a wind map of areas with medium to high potential. Later, in 1981, King Mongkut's Institute of Technology Thonburi (KMITT) and King Mongkut's Institute of Technology North Bangkok (KMITNB), in cooperation with Electricity Generating Authority of Thailand (EGAT), produced another wind