Standard test conditions (photovoltaics)

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The standard test conditions ( STC , English: Standard Test Conditions ) in photovoltaics are used to independently compare and evaluate different solar modules . For this purpose, uniform operating conditions for this state have been defined worldwide.

The data for current , voltage and power of a module temperature of 25 ° C and in the standard IEC 60904-3 (2016) Part III defined under standard test conditions apply at an irradiance of 1000 W / m² at the module level, spectrum of sunlight at a astronomical air mass of 1.5. This value takes into account the scattering and absorption of sunlight by the atmosphere. The power determined is usually given the non-standard designation Wp (power under optimal conditions).

Since the specified lamp spectrum, irradiation and module temperature cannot always be maintained during the actual measurement, the measured values ​​are calculated from the current measurement conditions under standard test conditions. The values ​​determined in this way enable the modules to be compared with one another, but the actual operating behavior cannot be derived directly from them. For example, with an irradiation of 1000 W / m², crystalline modules usually have a significantly higher module temperature than 25 ° C, which is accompanied by a drop in performance. The behavior of different cell types in weak light is also not taken into account with this value.

A performance check in the field (on the solar roof or open space system), which is carried out using STC, must take the following into account:

  1. Irradiation of 1000 W / m²
  2. Air mass AM of 1.5
  3. Cell temperature of 25 ° C

If these values ​​are taken into account in the mathematical evaluation, a measurement can be designated as an STC.

literature

  • Eckhard Rebhan (Ed.): Energy Handbook . Generation, conversion and use of energy. Springer-Verlag, 2002, ISBN 3-540-41259-X , 3.5.6.3 Specification of PV modules ( limited preview in the Google book search [accessed on January 24, 2013]).
  • Andreas Wagner: Photovoltaic Engineering . Manual for planning, development and use. Springer-Verlag, 2010, ISBN 978-3-642-05413-6 , 3.5.1 peak power measurement, doi : 10.1007 / 978-3-642-05413-6 ( limited preview in Google book search [accessed on January 24, 2013 ]).

See also

Individual evidence

  1. ↑ luis amir: Standard Test Conditions (STC): definition and problems. In: sinovoltaics.com. Retrieved December 5, 2017 .