Overview of Solar Thermal Applications

1. Overview of Solar ThermalApplications Unit 5 Source:

2. Use Policy • This material was developed by Timothy J. Wilhelm, P.E., Kankakee Community College, with funding from the National Science Foundation as part of ATE Grant No. 0802786. • All materials in this presentation are designed and intended for educational use, only. They may not be used for any publication or commercial purposes. Source:

3. Author, Editors/Reviewers • Author: Timothy J. Wilhelm, P.E., Kankakee Community College • Editors/Reviewers / Modifier: • Chris Miller Heartland Community College Source:

4. Objectives • Students will be able to describe, in very simple terms, “black body” absorption and radiation and their relationship to solar thermal applications. • Students will be able to list the basic residential applications for solar thermal technology. Source:

5. Objectives • Students will be able to discuss the basic requirements for passive solar architectural design. • Students will be able to discuss and describe how active solar thermal technology works. Source:

6. Thermal Applications = Using Heat • Typical Thermal Applications in Daily Human Living – Residential Dwelling Applications: • Space Heating • Water Heating • Cooking

7. Contemporary Thermal Sources • The Heat Energy Necessary for Space Heating, Water Heating, and Cooking is typically Converted from: • Electricity • Natural Gas • LPG • Fuel Oil • Coal • Wood • Other Combustible Fuels

8. Challenges Regarding our Conventional Sources of Thermal Energy • Limited, Finite Supply • All (except nuclear-fission sourced electricity) pump CO2 back into the atmosphere • All result in one or more additional, environmental pollutants • The cost of all is continually increasing • Most are not locally available and must be transported in

9. Moving Heat Energy to Where We Need it… • Heat is directed and moved via… • IR Radiation • Conduction • Convection

10. Conduction, and Radiation

11. Convection Source: http://cobblearning.net/rlimpert/files/2010/02/a3a421b29aedfa72.jpg

12. Conduction, Convection, and Radiation Source: http://cobblearning.net/rlimpert/files/2010/02/a3a421b29aedfa72.jpg

13. The Sun as a Source of Thermal Energy • “Black Body” radiation and absorption! • We see only reflected light • When we see “white” light, the “white” surface is reflecting all frequencies of visible light • When we see “red” light, the “red” surface is only reflecting the “red” frequency of visible light, and is absorbing all the other frequencies of visible light • When a surface appears “black” it is absorbing all the frequencies of visible light and reflecting none

14. “Black Body” Radiation and Absorption • “Black Bodies” absorb ALL frequencies • At temps below 200o C, “Black Bodies” (all bodies) radiate InfraRed frequencies • InfraRed radiation is HEAT! Source: http://www.popsci.com/files/imagecache/article_image_large/files/articles/colorfire_485.jpg

15. Solar Thermal Technologies • The basic ideas behind solar thermal energy are: • Convert solar radiation into heat energy via Black Body absorption • Trap the captured heat energy • Limit IR radiation losses • Limit Convective losses • Limit Conductive losses • Direct the captured heat energy into the desired zone or material via IR radiation, and/or convection, and/or conduction

16. Solar Thermal Technologies • Solar Space Heating vs. Solar Domestic Hot Water Heating vs. Solar Cooking • Passive vs. Active Solar Thermal Applications • “Flat Plate” Solar Collectors vs. Concentrating Solar Collectors

17. Solar Space Heating • Passive Solar Principles: • Insulate, insulate, insulate (especially the North wall) • Orient long axis of building E-W • Lots of South facing glazing • Thermal storage • Nocturnal insulation on South wall • Summer shading to avoid seasonal over heating

18. Passive Solar Principles Source: http://www.energysavers.gov/images/five_elements_passive.gif

19. Passive Solar Principles Source: http://www.solarbuildings.ca/c/sbn/img_db/alstonvale.JPG

20. Passive Solar Principles

21. Passive Solar Principles

22. Passive Solar Principles • Thermal Storage Media • Solid Thermal Mass • Trombe Wall • Water Columns, jugs, and barrels • Eutectic Salts

23. Passive Solar Principles

24. Passive Solar Principles Source: http://www.solar-components.com/BLUETUB.JPG

25. Passive Solar Principles Source: http://knowledgepublications.com/heat/images/Solar_Air_Window_Box_Collectors.gif

26. Active Solar Space Heating Principles • Same as Passive principles, but… • Add on external solar collectors • Add on fans or pumps to move fluid • Air or water or other FLUID • Different configurations of heat storage • May incorporate heat pumps • May be flat-plate or concentrating

27. Active-Solar Air-Heating Principles

28. Active-Solar Air-Heating Principles Source: http://www.yoursolarlink.com/blog/wp-content/uploads/solar_air_heater.jpg

29. Active-Solar Air-Heating Principles

30. Active-Solar Space Heating with Liquid Working Fluids Source: http://www.solarage.co.uk/res/embedded/swhsystem.gif

31. Solar Domestic Hot Water Heating • Can be active or passive (thermo-siphon) • Can be open loop • Open loop can be drain-down configured for freeze protection • Can be closed loop • Closed loop can be drain-back configured for freeze protection • Closed loop can be freeze protected by using antifreeze as the working fluid

32. Passive Solar DHW Heating Batch Tank Heating Thermo-siphon

33. Passive Solar Water Heating • Batch heaters

34. Passive Solar Water Heating • Batch heaters

35. Passive Solar Water Heating • Batch heaters Source: http://www.byexample.com/library/photos/projects/batch_collector/bc_01697.jpg

36. Passive Solar Water Heating • Thermo-siphon heaters Source: http://www.altensol.com.ph/?404=Y

37. Hot water outlet Storage tank Auxiliary Cold water inlet Schematic diagram of a thermosyphon solar water heater Intensive program: ICT tools in PV-systems Engineering

38. Laboratory model Intensive program: ICT tools in PV-systems Engineering

39. Typical thermosyphon solar water heater Intensive program: ICT tools in PV-systems Engineering

40. Active Solar DHW Heating System Design Governed by Need for System Efficiency and Freeze Protection

41. Active Solar Water Heating Source: http://www.amecosolar.com/waterheat.jpg

42. What type of system would I use in my area? • Warm climates • systems similar to those shown previously • systems will differ in design • Cold climates • freeze protection becomes critical • Indirect systems with heat exchangers • Drainback and draindown systems

43. Warm climates • Fluid in tank is • heated in collector • Most common system • in temperate climates

44. Warm climates This system is called a thermosiphon system. It does not have pumps, controllers, or any moving parts. Water is heated and the density of the hot versus cold water takes over from there. Works off natural thermosiphon actions in moving the water heated in the collector back to the tank and the cold water in the tank to the collector.

45. Direct circulation system Intensive program: ICT tools in PV-systems Engineering

46. Cold climates • Freeze protection • Reduce Scale • Non-potable fluids

47. Cold climates Indirect system with heat exchanger that contains fluids in collector that do not freeze. Heat exchanger is in the water heater.

48. Drain-down system When a freezing condition or a power failure occurs, the system drains automatically by isolating the collector array and exterior piping from the make-up water supply and draining it using the two normally open (NO) valves Intensive program: ICT tools in PV-systems Engineering

49. Indirect water heating system Intensive program: ICT tools in PV-systems Engineering

50. Drain-back system Circulation continues as long as usable energy is available. When the circulation pump stops the collector fluid drains by gravity to a drain-back tank. Intensive program: ICT tools in PV-systems Engineering