(Abstract): Monthly Average Solar Resource for
flat-plate collectors tilted at latitude for Nepal.
(Purpose): Provide information on the solar resource
potential for the data domain. The insolation values represent the
average solar energy available to a flat plate collector, such as a
photovoltaic panel, oriented due south at an angle from horizontal equal
to the latitude of the collector location.
(Supplemental Information): These data provide monthly average and
annual average daily total solar resource averaged over surface cells
of approximately 40 km by 40 km in size. The solar resource value is
represented as watt-hours per square meter per day for each month. The
data were developed from NREL's Climatological Solar Radiation (CSR)
Model. This model uses information on cloud cover, atmospheric water
vapor and trace gases, and the amount of aerosols in the atmosphere to
calculate the monthly average daily total insolation (sun and sky)
falling on a horizontal surface. Existing ground measurement stations
are used to validate the data where possible. The modeled values are
accurate to approximately 10% of a true measured value within the grid
cell due to the uncertainties associated with meteorological input to
the model. The local cloud cover can vary significantly even within a
single grid cell as a result of terrain effects and other microclimate
influences. Furthermore, the uncertainty of the modeled estimates
increase with distance from reliable measurement sources and with the
complexity of the terrain.