Submitted by elsbeth on Wed, 2009-10-28 10:37

Solar panel output

 

A solar panel’s output (= amount of electricity produced) is determined by the amount of irradiation that reaches the solar panel. The power produced by a solar panel is directly proportional to the irradiation, but decreases as cell temperature increases. In other words: the greater the solar irradiation, the greater the power that can be generated. However, the hotter the solar panel’s cell temperature, the lower the conversion rate. Output depends on:

  • the intensity of the solar radiation: the amount of incident sunlight.
  • the tilt: in the Netherlands, the highest outputs are attained at a 36º angle. At a tilt of between 20º and 60º, the annual output only decreases by 5%.
  • orientation: in the Netherlands, the optimum orientation is achieved when the panel is fixed at 5º west of due south.
  • the obstruction angle: this angle should be less than 15º on roof surfaces.
  • orientation (east, west or south).
  • surface area of the solar cells and modules.
  • Watt peak (=peak output): the electrical power that a solar cell supplies at an irradiation of 1000 W/m2 and a cell temperature of 25 degrees Celsius.
  • shade: a solar panel in the shade conducts less power, which results in a more than proportionate reduction in output because the panels are typically connected in series. Sources of shade to be mindful of include not only eaves and tree branches, but also tall buildings.
  • Cell temperature: leave adequate ventilation space around the panels so they can dissipate their heat. Higher temperatures mean less electricity output.
  • Quality of the solar cell (material)