Solar Collector Power Output


How much power do solar thermal collectors produce?
  • When planning for a solar thermal system, it is critical to consider the available solar radiation at the installation site.
  • Solar radiation is a highly variable power source. Radiation varies significantly from hour to hour, day to day, and location to location, based upon time, weather and geographic region.
  • It is critical to note that solar thermal collectors have a variable efficiency, dependent upon solar radiation intensity, fluid temperature, and air temperature.
  • Contrary to photovoltaics, using monthly averaged solar radiation data cannot be used to accurately simulate the output of solar thermal collectors.
  • In order to more accurately understand solar collector output a numerical model has been developed which simulates the power output of solar thermal collectors using 15 years of historical hourly solar radiation and temperature data from NREL. This takes into account the variation in efficiency of the thermal collectors.
  • Due to the variable nature of the weather in any location in the world, it is nearly impossible to predict future weather conditions. This tool aims to provide statistical insight on how a solar collector might perform based upon a historical simulation of solar collector power output. Using this historical simulation, it is the system designers responsibility to make an engineering judgement how the solar collector will perform in the future.
  • Please use the form below to specify the details of your configuration.

Collector Make/Model: Choose from several collector types to see if the CPC1518, or another make/model is the best collector for your application. The "theoretically perfect collector" is the incident radiation on the tilted surface and provides an upper limit on what a perfectly efficient solar collector could do in the configuration selected.
Collector Inlet Temperature (Tin): Recommendations: 30C (Radiant Heating), 50C (Domestic Hot Water, DHW), 50C (air handler for space heating), 80C (Absorption Cooling)
Collector Outlet Temperature (Tout): Recommendations: 40C (Radiant Heating), 60C (Domestic Hot Water, DHW), 60C (air handler for space heating), 100C (Absorption Cooling)
Altitude Angle (Collector Tilt):
Azimuth Angle (direction the collector is facing):
Location: Choose from 858 locations throughout the United States of America. Class 1 locations utilize higher quality input meteorological data than class 2 locations.
Minimum Altitude Angle at the Building Site: Minimum solar altitude angle for beam radiation due to obstructions present at the installation site because of nearby trees, buildings, hills, etc.
Minimum Azimuth Angle at the Building Site: Minimum solar azimuth angle for beam radiation due to obstructions present at the installation site because of nearby trees, buildings, hills, etc.
Maximum Azimuth Angle at the Building Site: Maximum solar azimuth angle for beam radiation due to obstructions present at the installation site because of nearby trees, buildings, hills, etc.
Number of Days to Average (Year Plot only): Increasing the number of days averaged will result in a smoother curve, however, an appropriatly sized thermal energy storage device would be required in order for the smoothed results to have any physical meaning.
Day to Plot: Choose the day to plot on the Day Plot
Year to Plot: Choose the year to plot on the Year and Day Plots
Choose the area in which the results will be presented with respect to:(useful for comparing collectors of different sizes)
Year Plot:Show Year Plot
Show Median Day
Show Selected Year
Show All Days
Show Minimum Year
Show Median Year
Show Maximum Year
Hour Plot:Show Hour Plot
Show Median Hour
Show Selected Day

Show Minimum Day
Show Median Day
Show Maximum Day
All Days and All Hours Plot:Show All Days and All Hours PlotIt takes much longer for this plot to be displayed.
Map:Show Site Location Map


Solar Collector Thermal and Optical Characteristics Used for the CPC1518


Year Plot

Download Data in .csv Format

Hour Plot

Note, there may be anomalies in the probability distribution near the sunrise and sunset times of the summer solstice due to the temporal resolution of the meteorological data and the contour plotting function.
Download Data in .csv Format

All Days and All Hours Plot


Site Location Map



If you have any comments, suggestions, questions, or if you identify a problem with this tool, please Contact Me.


©2007 - Andy Schroder