Ultrasonic anemometers measure the horizontal wind speed and direction as well as the acoustic virtual temperature. However, because of their high power consumption, a connection to mains power supply is required and their application at self-contained, solar-powered measurement systems is not feasible. Ultrasonics offer excellent performance ratings at well-powered measuring stations. At present they are not accredited according to the internationally valid MEASNET regulations. Ultrasonics are applied for wind park monitoring, on wind turbines and on offshore projects. Most ultrasonic anemometers can be fitted with electronically regulated heating.