External conditions for using solar energy in photovoltaics

A consideration connected with the possibilities of obtaining solar energy depending on external conditions, such as: the latitude ϕ, the solar declination δ, the hour angle ω was performed. The operation of photovoltaic modules in very cloudy conditions as well as under clear sky was taken into consideration. The results of the measurements of radiation power density that reaches the surface of the photovoltaic receiver for its different positions, for the geographic location of the cities of Poznań and Playa del Ingles and for different time periods (yearly and daily) are presented in a graphical form.