Worldwide annual optimum tilt angle model for solar collectors and photovoltaic systems in the absence of site meteorological data Articles uri icon

publication date

  • January 2021

start page

  • 1

end page

  • 13


  • 116056


  • 281

International Standard Serial Number (ISSN)

  • 0306-2619

Electronic International Standard Serial Number (EISSN)

  • 1872-9118


  • This study provides several models for accurately computing the annual optimum tilt angle for fixed solar
    photovoltaic arrays or solar collectors, in any location of the world. The optimum tilt angle that maximizes
    the annual energy yield can therefore be easily calculated in the absence of meteorological data and simulation
    software tools. The proposed models are calculated using global horizontal radiation data collected from 2551
    sites across the world. In the process, well-established submodels have been selected to estimate the hourly
    irradiance on any possible inclined surface, and its corresponding annual energy yield. After selecting the
    optimum angle for each location, through a regression analysis, a mathematical model that calculates annual
    optimum angles as a function of latitude has been developed. Furthermore, regression techniques such as neural
    networks and decision trees have been compared with the polynomial models. Finally, the results are compared
    to those obtained from high-quality 1-min measured irradiance data obtained at 52 research-class stations from
    the World Radiation Monitoring Center–Baseline Surface Radiation Network, providing a remarkably high
    number of validation data points. The results are analyzed, validated, and compared with previous research
    proposals proving the good performance of the proposed models.


  • Electronics
  • Telecommunications


  • solar photovoltaic; solar collector; optimum tilt angle; solar radiation; irradiance model