Spanish company Onyx Solar, through its U.S. subsidiary, has completed the installation of what it calls the largest photovoltaic (PV) skylight in the world. The PV double skylight sizing 27,500 square feet was executed for the new Novartis Pharmaceuticals Corp.’s headquarters in New Jersey.

The company says the skylight will allow the firm to generate free and clean electricity from the sun, equivalent to the lighting of more than 600 houses.

The PV skylight is comprised of 820 units of PV glass modules in large format and they incorporate photovoltaic crystalline perforated solar cells which the company says made the manufacturing process more complex as a result of the higher fragility of the cells. Such solar cells allow a more homogeneous natural light transmission through the building, enhancing its interior lighting which is key for any office space, according to Onyx Solar, who says the execution of the project was especially demanding because of the complexity of the skylight system which had to be movable (open and close) for maintenance purposes.