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SPA Calculator

Compute the solar position from universal time
and location using NREL's Solar Position Algorithm (SPA).
Required input values:
Enter start date:
Enter end date:
Select option for time output:   Units:
(::):

Enter site location information:







Optional input values:

of surface normal on horizontal plane, negative east) [degrees]


Check desired final output values:







Check desired intermediate output values:
Please read the disclaimer and copyright notice before using this product.
For more information about SPA and the C source code


For questions about the solar position algorithm contact: Ibrahim Reda
For questions about this website or calculator contact: Afshin Andreas