Solar Green Roofs

Many mistakenly believe that building green presents a binary choice for the rooftop – solar or a green roof. The truth is combining solar panels and a green roof offers the best choice with the benefits of both and a synergy that goes beyond.

Solar panels embedded within a green roof provide these combined benefits:

  • Cost savings with rooftop solar energy
  • Reducing and reusing stormwater
  • Reducing your carbon footprint with alternative energy production, and absorption of CO2 and particulate matter
  • Lessening the “heat island” effect
  • Reducing noise and energy use
  • Extending the life of the roof
  • Improving property values, and increasing rents
regis-weather

Regis High School, Manhattan

In addition, there’s a synergy in combining solar and vegetation that brings benefits both to solar panel efficiency and the biodiversity of the green roof.

Improved Solar Efficiency

A green roof, also known as a living roof, covers a building with soil and plants. The evaporation these plants facilitate makes the rooftop cooler. This effect enables photovoltaic cells to operate at peak efficiency. Panels mounted on a green roof will produce significantly more energy – up to 16% more – than those mounted on a non-living roof, especially during summer’s higher temperatures. Additionally, green roof vegetation removes pollutants and dust from the air that might otherwise interfere with a cell’s ability to produce electricity. (Source: Anacostia Watershed Society)

Improved Green Roof Biodiversity

While solar panels can take away rainfall and sunlight from green roof vegetation, the introduction of photovoltaic cells can actually strengthen the living roof by creating areas of biodiversity, where plants and animals adapted to less water and light can thrive. A more diverse roof is a more stable roof. (Source: Greenroofs.com)

In recognition of the solar green roof benefits, New York City’s Department of Buildings launched a new Green Roof and Solar Tax Abatement Program to encourage solar green roofs.