For your selected location, these tools show the annual average (mean) irradiance value (GHI, DNI, DIF) including a +/- (plus or minus) range. This tool directly incorporates a confidence interval, providing a range of expected values and a more realistic assessment. This value reflects the general terrain conditions in your area and is based on a combination of computer simulations and direct satellite observations.

You have the option of seeing the irradiance values in units of kWh/m²/day (kilowatt-hours per square meter per day) or W/m² (Watts per meter squared). To learn how to change your account settings click here.