Buildings, both residential and non-residential, are responsible for 40 % of final energy demand in Europe, and 36 % of CO2 emissions. Given this high energy saving potential, the European Commission has set the target for all new buildings to be almost zero energy consumption by 2020. The building envelope is decisive in this context. It has a great influence on the energetic behavior of the building, on the levels of comfort of the users, and on the general aesthetics. On the envelope it is possible to adopt passive saving measures through the design and use of advanced materials. At the same time, the envelope offers great possibilities for the integration of active renewable generation systems. Among the various existing systems, solar photovoltaic technology (BIPV) stands out for its simplicity in its integration, modularity, possibilities for interaction with other building generation systems, and compatibility with passive energy saving measures in the building. All analysts agree that the BIPV market has great potential for companies that manage to specialise in product differentiation, combining design and manufacturing flexibility with the standardisation of photovoltaic applications for building integration. Among the main demands that are detected in the market in relation to photovoltaic construction products are the following: Much of the available offer does not meet the needs of architects in terms of aesthetics, light transition needs to the interior, complementarity and support to passive systems for solar control and thermal insulation. —There is a lack of information from manufacturers to architects about compliance with the regulations applicable to the product. Most modules are only available in flat geometry, which limits the possibilities of design, and even optimal use of available radiation in a given location/orientation. —Product and installation cost compared to traditional building materials. This project proposes the development of a new product that responds to these requirements in a simple and versatile way. The objective of the SPHERES project is the development of photovoltaic modules with flat and curved geometries, semi-transparent, of high efficiency in photovoltaic production and high aesthetic level and comfort, through the implementation in laminated glass of a novel solar technology based on crystalline silicon spherical cells. This product shows great synergies with passive solar control and thermal insulation measures commonly used in buildings. The resulting glasses will be semi-transparent, with a high aesthetic level and visual comfort for the user. The spherical solar technology and the possibility of integration in curved glass mean a lower dependence on the angle of incidence of light, increasing the flexibility for its integration into the building. The product contributes directly to the solar control of the building. The introduction of aesthetic elements such as coloured or screenprinted glass is very simple in the interior glass of the laminate. Highly competitive target costs have also been established in the BIPV market. The main market that the consortium wants to access with this product is that of photovoltaic integration in high added value building: curtain walls, ventilated facades and skylights. But the product can also be exploited in the automotive glass market (solar roofs), sound barriers on highways, glass greenhouses, etc.
