Image: Wikimedia Commons
While attending a recent talk given by Paul Kephart, president of pioneering ecological design firm, Rana Creek, I heard an interesting assertion: Green roofs can improve the performance of solar photovoltaics by up to 30%. This would be due to the ability of the green roofs to lower the ambient temperature surrounding the panels, thereby boosting efficient operation.
Plants + solar PV may be an exciting possibility for synergistic systems on rooftops, especially in dry climates like California.
I have been looking around for studies or more information about this and came up with just a few articles that are linked below. Portland State University has a study underway on this topic.
This post is part of our definitions series on “eco-lingo” and technical terms.
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Image: U.S. EPA
“Green roofs”, or roofs that use vegetation to retain stormwater and reduce the ‘heat island effect’ of miles of sun-absorbing rooftops, are more well-known than a related roof-type, the “blue roof”.
Blue roofs use stormwater capture devices rather than vegetation to reduce runoff levels from rooftops. Blue roofs can contribute to sustainable building design and retro-fits in a number of ways. Some blue roofs are designed to temporarily harvest and house stormwater others may divert and infiltrate or slow-release stormwater. Since areas with large amounts of impervious paved surfaces may be subject to flooding, blue roofs can reduce the risk and associated damage and expense of localized flooding.
Blue roofs can also be employed strategically to avoid over-burdening combined sewage systems that are in danger of overflow and discharge into water bodies during storms.
New York City unveiled a new Green Infrastructure Plan in September that will employ blue roofs among its strategies to reduce sewage overage a target 40% by the year 2030.
Read an article on NYC blue roofs, here. A further definition of blue roofs can be found, here.
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What exactly does “sustainability” mean? How about “green”, “eco” or “environmentally friendly”? The truth is that these terms are just vague enough to mean many different things to many different people. With the staggering array of “green” products, ‘lifestyles’ and concepts being promoted by marketers and environmentalists alike (as well as the necessary coining of new terms to match new ideas) our definition series aims to make sense of the rising tide of “eco-lingo” and technical terms.
Many older cities face increasing stormwater management issues. Today’s video was put together by the Philadephia Water Department’s Office of Watersheds and gives a pretty good overview of an integrated approach.
The city is trying to address combined sewer overflows through a combination of traditional infrastructure and “green” infrastructure as the city is continuously rebuilt and repaired over time. The main goal is to prevent so much water from running off all of the impervious surfaces in the first place. More information on the approach is here.
New York state passed the “Electronic Equipment Recycling and Reuse Act,” requiring that manufacturers accept and recycle many types of e-waste starting in April 2011 (soon!)- NY State Dept. of Environmental Conservation and NRDC.
Green roofs are now required for many new buildings in Copenhagen – Treehugger.
A lawyer has started a blog focusing on legal issues specifically related to green building, with many recent posts focusing on the LEED rating system and the USGBC – Green Building Law Update.