Wind Energy

168 T. Weidinger et al.
2
3 4
1
5
6
7
8
9
3
3.5
3.0
2.5
2.0
< 1
1 - 1.5
1.5 - 2
2 - 2.5
2.5 - 3
3 - 3.5
3.5 - 4
4 - 4.5
4.5 - 5
5 - 5.5
5.5 - 6
> 6 m/s
Fig. 30.1. Annual wind speed in Hungary based on 55 automated meteorological
stations for the period 1997–2003 [4] (left panel); wind map of Hungary based on
wind measurements from 1997 till 2002 [3] (right panel)
Table 30.1. Average wind speed (m s −1 ) for the period 1970–1987, relative deviation
of the maximum and minimum annual mean wind speed from the average
(rel. min and rel. max, respectively) and that for wind energy (proportional to the
cube of wind speed), estimated from monthly wind roses (cub. min and cub. max,
respectively)
Station Average rel. min rel. max cub. min cub. max
Győr 2.70 (m s −1 ) −11.8% 14.3% −40.3% 31.5%
Sopron 4.38 − 8.9 6.7 −21.6 13.1
Szombathely 3.39 −14.1 14.4 −33.9 82.3
Pápa 2.56 −11.1 8.0 −30.6 26.3
Siófok 3.17 −21.0 23.4 −42.8 58.8
Budaörs 2.88 −14.7 16.5 −34.8 58.9
Budapest 2.87 −15.9 19.9 −46.9 72.7
Szeged 3.32 −6.5 9.6 −14.7 23.5
Kékestető 4.40 −23.1 12.8 −55.2 35.5
Relocation of a weather station also causes significant changes. For example
in Sopron (2) 1 the new location of the station is a former wind mill’s location;
here the annual average wind speed increased by more than 1 m s −1 .
The inter-annual variability of annual mean wind speed is an additional
source of uncertainty. In Table 30.1 this uncertainty is demonstrated. The
calculation is based on Annals of the Hungarian Meteorological Service. The
largest values were recorded at the western boundary in Sopron (2) and at the
“top” of Hungary, Kékestető (1,010 m elevation). This inter-annual variability
is the nature of the wind climate. The deviation of the annual mean from
the long term average is around 10%. In the wind tunnel of the Buda hills at
Budaörs (6), this type of deviation is about 15%, at Siófok (5) near Lake Balaton
or at Kékestető (9) this value is above 20%. For the period of 2001–2004
we got even larger deviations. Annual average wind speed for the latter period
1 Numbers in parenthesis after station names refer to their location in Fig. 30.1.
2.0
2.0
2.5
2.5
2.5
2.0
2.5
2.0
2.0
3.0 3.0
2.0
2.5