10.07.2015   SonSolar

Smoothing Effects for Wide-Area Employment of Wind Energy

150 -100 -50 0 50 100 150

Fig. 4 Seasonal comparison of average electricity generation from wind, quotient of average monthly values of July and January production 1979-1992; met. data: ECMWF.

The most favourable areas for electricity production from wind power in EU countries are dominated by winter winds. For this reason, as is illustrated in Fig. 4, the major contribution of wind generation occurs during this period.

The achievable production — Graph E) — Fig. 5 varies from month to month significantly more than the electricity demand — Graph G). The trade wind regions of northern Africa (southern Morocco and Mauritania, Graph c) and d))exhibit similarly strong seasonal variations, but their peak production is during the summer months. By purposefully selecting a combination of certain areas for production, the typical monthly electricity generation may largely be matched to demand. This fact is illustrated in Graph F), in which one-third of the rated capacities are assumed to lie within the EU, with the rest equally divided among the other regions. In this manner, the area of generation and thus the total potential is greatly expanded, simultaneously accompanied by very beneficial smoothing effects.

P_Mean/P_Rated

0.37 ■ a) Northern Russia and Western Siberia

0.28 b) Kazakhstan

0.38 c) Southern Morocco

0.36 d) Mauritania

0.30 [33] E) Good Wind Sites within EU and Norway 0.33 —F) Combination: 1/3 E) and each 1/6 a), b), 0.47^- G) Electric Demand within EU and Norway

Fig. 6 Seasonal comparison of average photovoltaic electricity generation, quotient of average monthly values of July and January production 1979-1992; met. data: ECMWF and NCEP

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Fig. 5 Relative monthly average: electricity production from wind turbines (WT) in selected good wind areas and electricity consumption of EU and Norway. a.) to d.) represent Extraeuropean production E.) represents European production and F.) is the combined production of wind power at all regions whereas G.) represents the average consumption in the EU & Norway weighted with the today’s rated power of all power plants installed. The variations in the electricity production from wind power diminish by transcending from the simultaneous feed-in from domestic European locations to generation that includes production from outside of Europe. In the case of a high percentage of electricity being produced from wind power, the instances of excessive generation will be significantly reduced as well as the periods of relatively low feed-in from wind power.

c) und d)

• 4.3 Temporal Behaviour of the Electricity Produced by Parabolic Trough Power Plants

Fig. 7 Seasonal comparison of average heat production by mirror arrays in concentrating parabolic power plants, quotient of average monthly values of December and July production 1983-1992; met. data: ECMWF and NCEP.

Due to the parallel configuration of the mirror elements, the trough array may partially block the rays of the sun when it is low on the horizon. For this reason, and because of the low angle of incidence during the winter, the output varies throughout the months of the year in addition to random changes of incident radiation caused by local weather phenomena. This effect is diminished gradually while approaching equatorial latitudes, but it is still distinctly noticeable even at locations in southern Mauritania, where the achievable production in December reaches more than 80% of July production, as indicated in Fig. 7. Solar thermal generation alone is therefore not adequate to track the seasonal variations in European electricity consumption. In combination with European wind power, however, this requirement may be quite easily met.