Instructions: Select your location to display the GHI and Average Temperature.
The GHI (Global Horizontal Irradiance) is an average measurement of the total light energy you can expect to contact a horizontally orientated solar panel. This can be approximated to the number of equivalent full sun (kW-hr/m2/day) hours per day. If you multiply the GHI by the nameplate wattage of a solar panel (Pmax), you can approximate the amount of kWh a solar panel will produce on an average day. The second lowest month is used in the Watt Hour Worksheet calculations for the number of solar panels needed.
The Average Temperature is the average monthly temperature at 2 meters off the ground. The highest average month is used in the Watt Hour Worksheet calculations to estimate the cycle life expectancy of lead acid batteries.
These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program.