Solar thermal energy
Practical Action
Figure 3: Examples of average monthly global variation of solar insolation in a year
(NASA Earth Observations Website)
The analysis tool enables users to quantitatively investigate the variations in solar insolation in a
particular region throughout the year. Three snapshots of either a daily average, average across
eight days or monthly average, can be compared at once and presented in several different
ways; either a probe, which gives the insolation at a particular point on the globe, a transect
through a region (see Figure 4) or an average across a defined region. All three methods can be
specified by the user.
The average solar
insolation during 3no
months is compared
Comparison of the
variation in average
solar insolation with
distance across the
transect
Transect specified
for investigation
Interactive interface
of analysis tool
Figure 4: Screenshot of NASA Earth Observations Solar Insolation Analysis Tool
Each set of data can also be translated into the Google Earth software. This can be used to gain
an overall impression of global solar insolation variation at a particular time.
Figure 5: Data from NASA Earth Observations viewed in Google Earth
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