The result is absolutely satisfying. The main objective of having a photovoltaic installation as a fully integrated element in the building was an absolute success, as the qualities of double functionality sought were provided. Using renewable energy is a key objective in society in general, and architecture in particular, and photovoltaic glazing allows it to be incorporated in a natural way in necessary elements of the interior space. (Arch. Ana María Montiel Jiménez, estudio ATARIA)

The San Anton Market project was a technical challenge for Onyx Solar since it was the first one that they executed using photovoltaic glazing with an insulating gap between two panes (IGU, Insulated Glazing Unit). It created a twofold challenge as it was necessary to provide a solution to the exit of the wiring from the rear part of the photovoltaic glazing through the connection box and, at the same time, to find a technical solution to hide the wiring that interconnects the glazing units with each other and the strings that reach the inverters. The design of the skylight in a saw-tooth pattern was the most suitable solution to position the junction boxes on the photovoltaic glazing offsets. The work carried out by the architectural company’s team, the construction company and Onyx Solar technical team was completely coordinated during the execution of the project, which allowed agile solution of any small setbacks that occurred during the different project stages. The final result of the skylight was satisfying. It was possible to achieve the goals of integrating 100 % photovoltaic glazing with an insulating air gap and allowing the light to pass into the building in a controlled manner. The integration with the building is so satisfactory that the employees and users of the Mercado de San Anton building are unable to perceive that part of the energy they consume is being produced cleanly “over their heads” thanks to the sun. (Arch. Ángel Gallego, Onyx Solar)

Although the initial cost of this skylight could be higher if it is compared to conventional solutions because of the photovoltaic and electrical components, economic viability is achieved due to the capacity of the PV glazing to generate free electricity from solar light and the passive properties that reduce climate control loads and HVAC demands. A feasibility analysis was done on the basis of total cost and an estimation of electricity generation per year of about 7,748 kWh. Under these conditions, the energy price was estimated to be about 0.02 €/kWh. Besides, the use of the BIPV solutions could lead to a reduction of 34 % in HVAC energy demands with 55 % as the internal rate of return and a payback less than 2 years.

Low-E photovoltaic glazing has a Solar Heat Gain Coefficient (SHGC) that is much lower than that of conventional laminated glazing. A low SHGC value is critical for thermal comfort, particularly for hot climates such as Madrid.