The Importance of Accurate Solar Data for Designing Solar Photovoltaic Systems-Case Studies in Spain

Renewable energies have experienced a great growth in recent years, and nowadays participate in the set of energies used in developed and developing countries to produce electricity. Among these technologies, photovoltaic energy, which produces clean electricity from the Sun, is the one that has grown faster, and its implementation all over the world is a guarantee of a solid and efficient energy technology. Nevertheless, in order to design very efficient solar energy systems, it is crucial to have a good solar radiation database. There are databases where it is possible to find information on solar radiation, but only for horizontal surfaces. Afterwards, it is necessary to transform the horizontal solar radiation data to tilt solar radiation data. This transformation is not easy, and the application of complex mathematical equations, and expressions, and difficult algorithms must be done. An application called virtual laboratory OrientSol 3.0 which allows the user to easily obtain the solar radiation for any tilt surface has been developed by us. Thus, our main objectives in this paper are to present the developed virtual laboratory and to explain its main features and core functionalities. In order to point out the difficulties and complexity of the transformation of horizontal solar radiation data to tilt solar radiation data, we will present some examples of the results this application provides and compare the solar radiation data supplied with this application with some other solar radiation data obtained from other databases.