AVERAGE SOLAR INSOLATION, HORIZONTAL FLAT PLATE 
(from National Renewable Energy Laboratory) 
by Jon D. McWhirter, Ph.D., P.E
for BuildingCircles Organization

 
This graph shows solar energy's availability during the year, calculated in KW hours/square meter/per day, based on data from the National Renewable Energy Laboratory. 

Thermal Storage and Use for Annual Solar Heat Storage System
Copyright (c) 2006 by Jon D. McWhirter.  All rights reserved.