5 ms·

I can't quite grasp this - 40% to what? Availability of photons? What is 20% vs 40%? Same size cell putting out twice the power for the same sunlight? Okay, b

• dagw 12y ago
  40% of the total electromagnetic radiation that reaches the cell is converted to electricity.
  • pingec 12y ago
    What happens with the other 60%? Turns into heat and/or is reflected?
    • CapitalistCartr 12y ago
      Yup, same as solar energy hitting any surface. It becomes heat.
      • melling 12y ago
        ...or is reflected off...
• mabbo 12y ago
  The photons carry energy. Since energy can't be created, there is a physical maximum amount we can extract from sunlight. These folks are extracting 40% of that maximum.
• Htsthbjig 12y ago
  In Spain or in Australia or in Sahara desert you could get over 1000 Watts per square meter of irradiance in summer. So with a 40% efficiency you could get 400Watts per square meter if there is no clouds and the panel is perpendicular to the sun. The good thing is that in Spain, Australia or Sahara desert you have entire months without clouds in some places.
• jpmattia 12y ago
  > I can't quite grasp this - 40% to what? It's power efficiency. Sunlight hits the earth with power density Pi (measured in, say, Watts/m^2) and the solar panel puts out Po for the same area. They've measured Po/Pi to be 0.4