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The energy consumed to cool buildings is very elevated and solar gains represent a high percentage of these cooling loads. To minimize the thermal load it is necessary to control external shading systems. This control requires continuous measurement of solar radiation in different locations of the building. However, for such applications the use of conventional irradiance sensors increases the cost and reduces the profitability of the installation. This paper is focused on the development, modeling, and experimental validation of low cost irradiation sensors based on photovoltaic effect in order to reduce the costs of dynamic external shading devices and to improve the profitability of the system. With this proposal, firstly, small commercial photovoltaic cells have been adapted for use as an irradiation measurement device. Subsequently, quasi-stationary and continuous experimental measurements of these silicon cells, facing south and installed horizontally, have been carried out in Jaén (Spain) in 2009 and 2010. Finally, a nonlinear multiparameter function has been developed to evaluate the irradiance using the electric current generated by the cell, cell temperature, ambient temperature, and absolute humidity. A favorable agreement between the model predictions and experimental data has been observed with a coefficient of determination around 0.996 for all cells. [ABSTRACT FROM AUTHOR]

The high emissions of substances harmful to the environment associated with the activity of people, has become a point of extreme importance, since it depends on the subsistence of life on the planet [1]. Manufacturing processes and the application of new technologies improve substantially the life, but some processes contribute more to the damage to the environment. These manufacturing processes require a high consumption of energy and resources, which entail environmental impacts, some of them not quantified. For this reason, the reduction of emissions has become the battlefield in the fight for the preservation of planet. To determine and quantify the impacts that occur in a product, process or system, it is necessary to perform an analysis of the flows of energy and resources that occur throughout its life cycle. That is why the LCA has become a very important tool in the process of transition to a low-emission production economy [2]. There are systems that, although considered renewable, also produce impacts on the environment. That is why, the present work, and through the LCA, determines the impacts produced by two heat generation systems, to later be able to compare them with each other. • Public buildings cause environmental impacts that must be determined. • Energy production systems in public buildings are responsible for high energy consumption. • LCA provide us environmental aspect for the selection of energy production systems. • Resource depletion and CO 2 emissions are the most important impact of systems studied. [ABSTRACT FROM AUTHOR]