Comparison of PV Cell Temperature Estimation by Different Thermal Power Exchange Calculation Methods

Abstract

A steady-state thermal model for calculate the tem-perature  of  a  photovoltaic  (PV)  module  has  been  developed  for outdoor  installation  such  as  ground-mounted  systems.  The  PV temperature  is  influenced by  environmental  variables  such  as: irradiance  ambient  temperature,  intensity  and  direction  of  the wind,  module  design,  orientation  and  mounting  structure.  As well  as  it  is  influenced  by  electrical  parameters.  In  literature some single layer thermal balance consider only an overall heat transfer  coefficient  as  a  function  of  wind  speed,  neglecting  the radiative  thermal  flux. In  this  paper,  five  thermal  balance  are compared  and  it  is  shown  that  the  radiative  term  cannot  be neglected, otherwise the PV temperature could be overestimated for  low  solar  radiation  intensity  and  it  could  be  underestimated for high solar radiation intensity. For this reason, the percentage contribution  of  the  heat  exchanges,  normalized  as  function  of normal  incoming  solar  radiation,  are  evaluated  for  wind  speed within 1 m/s (natural convection).