Many national businesses produce sizeable carbon footprints but very few actually do anything about it. However, thanks to new guidelines from the Department of Energy, the United States Postal Service has rolled out a plan to make itself one of the greenest delivery companies in the country by cutting its energy usage. The postal firm has said they are looking at green roofs and optimally-efficient energy management systems in their efforts to further reduce their power needs.
For postal depots, one of the largest consumers of energy is air conditioning. These massive centers are prominent ‘heat islands’ — their black and/or dark roofs cause an increase in ambient temperature and as a result, more air-conditioning is needed to provide a comfortable working environments. Not just that, but air quality is also hampered.
To help mitigate the environmental and economic costs of cooling, USPS aims to embrace green roof initiatives where they can, as specified by the Energy Department. For example, in Manhattan Midtown, the USPS has converted the top of the Morgan Mail Processing Facility into a green roof. This 2.5-acre wide green roof is the largest green roof in New York City. By installing a green roof, buildings can not only reflect sunlight and therefore reduce heat gain, but they can potentially save up to 40 percent on their energy bills each month. Other advantages include a reduction of polluted storm water run-off (75 percent in summer and 40 percent) in winter.
The USPS has also been implementing systems such as the Enterprise Energy Management System to save some $400 million since 2007. More than $1 million of this was as a direct result of green roofing. With measures like green roofing and LEED certifications, the USPS has cut energy use by 21 percent since 2003 and reduced greenhouse gas emissions by 20 percent.
The USPS’s long-term plan is to economize energy consumption by 30 percent by 2015. Amazingly, it has already met 70 percent of this target, leaving only about one third of the goal left to go.
+ USPS
The project very nicely demonstrates how bad existing and many new buildings in the US are. 4 inch more of insulation would have at least 100% better insulations value that any extensive green roofs and it would cost only 10% of a green roof.
Insulation works year around and don\\\’t decrease the value in winter like green roofs do. Thicker insulation (min. r-65 is required in Europe – NYC r-38 ceiling and much less walls) all around the building (not only on the roof which is typically only 30% of the building surface) could save more than the double of what they are currently doing.
Everything combined with a green roof would get close to meet European requirements from 1990 in most big cities – to get to the level of current European requirements it takes much more.
Nevertheless they are starting to do something and as usual the press releases are bigger than the benefit for the environment.
This is my own European green roof expert perspective.
jbi