EME 811
Solar Thermal Energy for Utilities and Industry

8.0 Introduction


Last year, I made a refrigerator in my basement. And I needed … to figure how … there is no such thing as 'cold.' There is only less heat.

— Alton Brown

Cooling needs are an excellent fit for solar thermal energy because of the often-synchronous nature of the energy source and load schedule. What we know of as refrigeration or cooling is simply the moving of heat from our cold zone (building space, refrigerator, etc.) to a heat sink (often the ambient air). The driving of heat from a cold space to a hot space requires the input of energy because that is not the natural direction that heat would flow. An analogy would be pushing a cart uphill, when it wants to roll downhill, requiring the input of energy to get the cart to move uphill. Depending on the type of technology that is used, thermal energy can drive heat in a desired direction, thus creating “cold,” which is actually just less heat. Solar thermal energy is often thought of as some unique source that must have complex technology to convert it to useful work. That is not the case. Solar thermal energy is no different from any other type of thermal energy. Depending on the collector setup and working fluid, different temperatures and operating temperature ranges can be obtained. This heat can then be used for any thermal process that would normally be driven by some other heat source such as natural gas, propane, or electric resistance heat.

Learning Objectives

  • Identify different types of solar cooling - e.g. absorption chiller, desiccant, etc.
  • Use the psychrometric chart to explain cooling effect
  • Select a solar thermal solution for a residence that helps address cooling requirements.

What is due for Lesson 8?

This lesson will take us one week to complete. Specific directions for different assignments are given in the table below and within this lesson pages.

Tasks Assignment Details Access/Directions
Readings Required  Registered students can use the following link to access the online textbook through the University Library.
Quiz 10 multiple choice questions based on lesson readings  Registered students can access the quiz through the Lesson 8 Module in Canvas.
Assignment  Cooling system mini-proposal  Specific directions for the assignment are provided on the respective page of this lesson.
Discussion  Solar cooling systems - implementation examples  Please see additional directions for this discussion in the Lesson 8 Module in Canvas.


If you have any questions, please post them to our Questions and answers discussion forum in Canvas. I will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.