Solar energy is one of the most promising alternatives since it represents an inexhaustible and free source of energy. The aim of my MASc thesis is related to dynamic modelling of a solar thermal collector on the GAMS environment. The key idea is to reduce the use of fossils fuels by taking advantage of solar energy through a solar thermal collector. The main objective in my research is to find the appropriate operating conditions for this process that can maximize power output in the presence of changes in the environment. The dynamic model applied to determine the solar thermal collector output temperature is represented by a set of differential equations that were discretized using orthogonal collocation on finite elements. The operation of the solar thermal collector involves integer decisions since multiple units can be turned on/off depending on the external factors affecting the plant and energy requirements. Hence the proposed optimization model was formulated as a Mixed Integer Nonlinear Programming (MINLP) problem that was implemented on the GAMS environment. Different scenarios have been analyzed taking into account changes in the weather.