I am not sure whom at the US-DOE to contact but the EPW weather tapes
from the E+ Weather Data web site for Cadiz, Spain, and City Real,
Spain, have corrupt direct and diffuse radiation data. The total
horizontal radiation data make sense but direct and diffuse radiation
levels are somehow offset leading to non-vanishing values at night.

It would be wonderful if the DOE announced a contact email on the E+
Weather Data web site so that such bugs can be reported and fixed as
they can take quite some time to locate. If such a contact email already
exists, I did not find it. Having said this, I am of course very
grateful that the DOE provides the files free of charge in the first
place!

Christoph