The term green roofing has two meanings; actual green roofs covered with soil and vegetation, and energy efficient roofs that utilize green building technology to provide sustainable, Eco-friendly, and energy efficient building envelope protection.
Green Metal Roofs
Metal is a green building material that offers long lasting protection and can be recycled at the end of its service life. Metal roofs are light weight and can be installed over the existing asphalt shingle roof. This eliminates the mess and helps to protect the environment. Modern-day Metal Roofs are coated with special reflective coatings that reflect up to seventy percent of the solar radiation, which can result in over 20-30% energy savings during the summer months. The reduced load on AC will result in reduction of green house gases released into the environment.
PV Solar Integration
A house or a building that is protected by an EnergyStar-rated metal roof is already considered green, but there is a way to take the energy efficiency of such a roof even further. With standing seam metal roof you can now integrate PV solar roof laminates.Photovoltaic Solar Laminates attached to a Standing Seam Roof:
How Does Solar Power Work?
A photovoltaic cell generates electricity directly from sunlight. When sun light hits photovoltaic cell, electrons get set free creating electrical current. In traditional solar roofing, flat photovoltaic solar panels can be attached to the south facing side of the roof using roof penetrations. One of the issues with using traditional solar panels on a typical asphalt shingle roof is that at some point an asphalt shingle roof will require replacement and a temporary dismantling of solar panels. This of course can be expensive and time consuming.
PV Thin-Film Solar Laminates
Newer technology has brought out thin-film laminates panels that can be easily attached to a standing seam roof. – The advantage of this set-up is that there are no roof penetrations required as the panels are mounted to standing seam panels using peal and stick method.
Grid-tied Solar Power Systems
A Grid-tied system allows home-owner sell excess electricity to the greed, when there is a surplus, and use the grid power when the solar panel do not produce enough electricity or during the darker hours of the day. There are also off the grid solar roofing systems that require expensive set up with the special batteries to store the electric energy generated by PV solar panels.
Green Roof Gardens
Unlike green building accredited roof systems, green roof gardens refer to soil and green vegetation that grows on the roof. Green roofs can be planted over a PVC membrane that can withstand standing or ponding water. Of course, such a flat roofing membrane has to be completely waterproof. A well designed green roof pond may include water drainage for collection and irrigation.
Green Roof Containers
A typical green pond roof garden takes a very long time to build, and an alternative has been developed using containers of boxes that contain vegetation and get arranged on top of the roof using some sort of pattern.