What is the primary benefit of installing a photovoltaic system on a building's rooftop?

Installing a photovoltaic system on a building's rooftop primarily provides on-site renewable energy. This means that the system generates electricity from sunlight directly where it is used, decreasing the reliance on fossil fuels and grid electricity which may be generated from non-renewable sources. By harnessing solar energy, buildings can become more self-sufficient and significantly reduce their environmental impact.

Generating energy on-site also allows for an immediate reduction in electricity costs, as the building can use the produced power rather than drawing from the grid, leading to greater energy efficiency and resilience during power outages. This aligns closely with the goals of LEED certification, which emphasizes the importance of sustainable practices and renewable energy sources in reducing overall energy demand and fostering renewable energy use.

While other answers touch on important benefits of solar energy, such as potentially lowering energy consumption or decreasing a building's carbon footprint, the central focus of the question is the on-site generation aspect, which is directly achieved through the installation of a photovoltaic system.