The annual diffuse radiation of nearly 19 % varied from the least cloudy year to the cloudiest year.
Skalík Lukáš 2015, 'Long-Term Weather Data Measurements From A Danish Climate Station And The Weather'sInfluence On The Thermal Performance Of Solar Collectors', Slovak Journal of Civil Engineeringhttp://www.degruyter.com/view/j/sjce.2015.23.issue-2/sjce-2015-0009/sjce-2015-0009.xml?format=INT. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)