Solar Energy: Conduction and Heat Transfer

How Solar Energy is Used:

• Direct conversion into electricity --> Photovoltaics
• Fixing of atmospheric Carbon into the biomass --> photosynthesis
• Converting into heat energy for space heating, driving heat engines, etc

The Key to efficient use of solar energy lies in efficient modes of heat transfer. There are three possible modes:

• Conduction
• Convection
• Radiation

Thermal Conduction:
• heat energy flows from regions of high temperature to low temperature
• wide variation among different materials --> depends on the density of free electrons in the material

  Thermal Conductivity of some Materials:

  • Silver 4.2
  • Copper 3.9
  • Gold 2.9
  • Aluminum 2.0
  • Steel 0.5
  • Concrete 0.02
  • Brick 0.01
  • Wood 0.001
  • Air 0.0002

So Clearly metals are required for efficient heat transfer.

Heat flow through a wall:

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The Electronic Universe Project

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