Knot (unit) fluids (tidal streams, river currents and wind speeds) are also measured in knots. Thus, speed over the ground (SOG) (ground speed (GS) in aircraft) and rate of progress towards a distant point ("velocity made good", VMG) are also given in knots. Until the mid-19th century, vessel speed at sea was measured using a chip log. This consisted of a wooden panel, attached by line to a reel, and weighted on one edge to float perpendicularly to the water surface and thus present substantial resistance to the water moving around it. The chip log was cast over the stern of the
Wind power in Thailand kW capacity at Hua Sai District in Nakhon Si Thammarat Province, and later in 2009, another of 1.5 MW capacity. Also in 2009, two wind turbines of 1.25 MW capacity each were installed by EGAT at the upper reservoir of Lam Takhong Cholapawattana power plant, a hydroelectric power plant in Sikhio District, Nakhon Ratchasima Province, becoming Thailand’s first large electricity-generating wind power plant. Thailand has relatively low average wind speeds with most areas being of class 1-1.4 wind speed, or about 2.8–4 m/s measured at 10 m. This is because Thailand is near the equator which has generally low wind