4.6 Load Matching
Solar power has good load matching for peak summer loads due air conditioning and irrigation. However, wind power for large systems is more economical and at 50 m the low average values by month for summer are 250 W/m2 compared to solar average values of around 300 W/m2 for July and August. The solar values are on a 24 hour basis and peak values during the day for solar will exceed 1,000 W/m2.
Another way to estimate load matching is to examine a typical day for the month. The typical day is calculated by averaging the values for the 15 minute data points for the month. The typical day for solar has little variation which is why solar power can be considered as 6 hours of peak value.
Even though the average wind power by month is low during the summer for sites along the Rio Grande River, the typical day indicates there is some load matching as wind power increases in late afternoon. Sites further from the coast peak at a later time (Fig. 4.22). For the High Plains, there is a larger wind shear at night from May and even into July due to thunderstorms building up in the late afternoon (Fig. 4.23). As expected, predicted power output from wind turbines, averaged over 15 minute periods, closely follow the power for a typical day . The typical day for each month can then be plotted on a 2D or 3D graph for the year to see the time of day trends (Fig. 4.24).
Figure 4.22. Wind power for a typical day for sites along Rio Grande River, July 96. Figure 4.23. Wind power for a typical day for the High Plains, May 96 Figure 4.24. Wind power, W/m2, at 40 m for typical day by month for Carta Valley, 1996.