Page 76 - Design of Solar Thermal Power Plants
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66 2. THE SOLAR RESOURCE AND METEOROLOGICAL PARAMETERS
FIGURE 2.6 Daily mean direct normal irradiance for Badaling during the four seasons
of 2009.
We can see from Fig. 2.7 that in Badaling, 28 days in 2009 had a daily
2
mean DNI over 600 W/m , accounting for 8.1% of the yearly total; 49 days
2
with a daily mean DNI within the range of 500e600 W/m accounted for
14.1% of the yearly total. Days in the year with a daily mean DNI over
2
300 W/m accounted for 55%.
Fig. 2.8 and Table 2.5 show the number of days during the four sea-
sons in Badaling with satisfactory, typical weather conditions. Fig. 2.8
indicates daily mean solar DNIs for representative days typifying the
