The instrument replacement of cup/vane wind measurements to sonic (THIES 2D) has a negligibly small influence on the climatology of windseries. The comparison is based on simultaneous measuremnents on nine locations for about one year. Despite wake effects average wind direction deviation is far less than WMO-requirements, the deviation is
around 3 degrees for wind direction, for average wind speed and gust deviate about 0,1 m/s.
Calculations of potential wind will not significantly be effected by sensor replacement, but require fundamental study.
G Groen. Comparison of parallel wind measurement with Sonic and Cup-Vane at nine locations for climatological applications
KNMI number: IR-2011-01, Year: 2011, Pages: 15