Photovoltaic ventilated façade as an energy efficient measure for building retrofitting

The expected relevant role, within the new energy paradigm of photovoltaic (PV) solar energy, is mainly based on the rapid research and development advances in the PV field. In this sense, the current state of the art of these innovative technologies has allowed reaching the integration of PV glass products in buildings in an attractive and efficient manner. This approach is known as Building Integrated Photovoltaic (BIPV) Solutions which insertion ensures an enormous future for the distributed energy approaches as an energy-efficient measure for retrofitting applications. In this respect, Onyx Solar participates as a partner of HERB Project (Holistic Energy-Efficient Retrofitting of Residential Buildings) within the funding of the European Commission through its 7th Frame Programme. The HERB Project aim is to implement active and passive energy efficient properties in residential buildings already existing and located in several countries around Europe. Therefore, BIPV solutions are one of the technologies developed. As a first step, the PV ventilated façade was evaluated by means of computational modelling and façade prototype testing through a prototype in a Paslink test cell. This analysis is very useful for obtaining critical information concerning temperatures in the different layers of the wall, characterization of the air behaviour, heat generated within the façade air chamber and electrical production. Then, Onyx Solar has coordinated a family house retrofit in Gotarrendura, a village of Ávila (Spain). Among the wide range of retrofitting solutions used, it has been included the integration of a PV ventilated façade using opaque and semi-transparent glass based on a-Si active layer. This paper summarizes relevant results and conclusions of the research studies, testing carried out and the real case study mentioned whose combination demonstrates the potential of these measures in the field of energy-efficient retrofitting.