AEA’s Green Roof and Solar Installations
In October of 2011 the Association for Energy Affordability completed construction on a series of projects on the roof of our Bronx, NY training facility that significantly reduce our environmental impact. Our site now includes solar photovoltaic panels, solar thermal collectors, solar tubes and a planted “green roof.” In addition to the benefits these features provide in the form of cost savings and sustainability, beginning this summer AEA will offer hands-on solar array design classes, and Future Green Studio, the green roof designer, will provide green roof installer classes at AEA’s facility.
The 102 solar photovoltaic panels on AEA’s roof have a total capacity of 21 kW. Since commissioning in January of this year the panels have so far generated approximately 14,000 kWh of electricity, saving over $3,000 in energy costs. Projected annual energy production is 25,756 kWh, reducing costs by $6,181 and avoiding 39,747.60 pounds of carbon dioxide emissions per year, equivalent to taking almost 4 cars off the road.
Since installation, the solar thermal units have provided 57% of AEA’s hot water consumption. AEA uses two types of solar thermal systems: an evacuated tube collector and a flat plate solar collector. Operating two different solar technologies in the same environment allows AEA to measure and compare the production and efficiency of each. Any hot water that exceeds current demand is diverted to a condensing boiler and used for space heating in the building.
The green roof on AEA’s facility serves multiple purposes: it reduces the need for artificial heating and cooling inside the building, reduces stormwater runoff, sequesters carbon dioxide and provides a space for hands-on green roof trainings. The native plant life on the roof deflects solar heat and insulates the building, thus reducing the need for artificial heating and cooling. A green wall planted with drought-resistant plants and green trellises with rapid growing vines provide a visual screen for employees and trainees, while also sequestering carbon and other pollutants from nearby streets. The soil and plant life retain rainwater, reducing the amount of stormwater runoff that would otherwise divert to the surrounding streets and water treatment facilities. In New York City, as in many urban areas, stormwater runoff is a major environmental concern due to the potentially high amount of pollution collected by stormwater as it travels over city streets to the surrounding ocean, waterways and sewers. Excessive stormwater can cause sewers to overflow, as happens in New York every year, pushing untreated water into area waterways and causing illness. Through the use of water monitoring stations on both the planted portion of the roof and the “flat,” unplanted portion, AEA continually monitors stormwater retention rates. During April’s heaviest rain the flat roof testing area collected four quarts of water while the green roof testing area showed no excess accumulation, meaning that the plants and soil captured 100% of the rainwater that would have otherwise drained to the surrounding streets and sewers.
AEA is using these green technologies to expand our already robust suite of trainings covering energy efficiency and sustainability. AEA’s solar design classes will give students the skills needed to design solar photovoltaic and solar thermal arrays for a variety of applications. The green roof training offered by Future Green Studio at AEA will teach students the fundamentals of green roof design, installation and maintenance as well covering New York policy and incentives for green roofs. Classes include lecture and workshop time where students will have the chance to literally get their hands dirty.
AEA will continue to monitor the production and efficacy of our green roof and solar installations, and we are excited to see the long-term results. Between the positive environmental impact of these features, and the training offerings that help expand knowledge and adoption of such green technology, AEA is proud to be a part of the growing movement toward on-site renewable energy and productive urban landscaping.