I recently attended A View from the Top: Sustainable Roofs in Boston, a seminar organized by the Boston Redevelopment Authority (BRA) at the Federal Reserve Bank. The event featured a showcase of green-roof and solar companies and several presentations on creating an environment to support more roof greening in Boston.
Galen Nelson, Green Tech Business Manager at the BRA, and Jim Hunt, Boston’s Chief of Environmental and Energy Services, spoke of the city’s efforts to promote sustainable roofing. Since incorporating LEED standards into its building codes, Boston has seen a 500% increase in its solar capacity. The City has also created a solar permitting guide to instruct developers on every stage of the process for building and installing a solar array on their property. Hunt announced that the Mayor has filed an ordinance with the Boston City Council that will reduce permitting costs for new PV units by a whopping 60%.
Moving on to other green rooftop tech, a representative from Carlisle SynTec explained the benefits of vegetative roof technology to the audience. It can reduce cooling costs by 7-35%, heating costs by 5-10%, doubles the roof life expectancy (the roof is completely shielded from UV ray damage and insulated against dramatic temperature changes). In addition, environmental benefits include a reduced heat island effect, noise reduction of 40db for inside the building, purification of storm water through the garden’s growth medium, reduction of airborne particles, and it even keeps the temperature within 5 degrees of ambient. If there are solar panels on the roof, the consistency of this temperature helps improve their efficiency as well.
The garden is actually synthetic, made with several layers of insulation and permeable materials that can hold water and nutrients and let plants grow.
Such roof gardens are already in some Boston locations. The Seaport Hotel’s is quite impressive:
And the Yawkey Center for Cancer Care at Massachusetts General Hospital will provide a rooftop healing garden to help aid patient convalescence, in addition to all the benefits of a rooftop garden as described above.
Also present was the firm Nexamp, a solar PV installer, highlighting its tech and some local businesses who have shown leadership in PV installation. In particular, they pointed out Boston Sand and Gravel, which boasts a 110 kW PV system on its premises:
New England Solar Hot Water was also there, demonstrating its solar-heating technology. The equipment is essentially a plumbing system, holding water that is heated by the sun and then used to heat the home to which it is attached. While this may feel somewhat more mundane compared to PV cells, it boasts a 50% system efficiency in how it uses the sun’s rays. PV efficiency is still in the teens.