Standing among the flowers and plants on the roof of Batten Hall on a recent August day is reminiscent of standing in a country meadow on a late summer afternoon. Petals flutter slightly in the wind and bees buzz from flower to flower seeking nectar. Many of the bees come from two beehives recently installed on the opposite corner of the roof. Just a floor above us, 436 solar panels are converting the intense summer sun into electricity that will be used to provide power to the Harvard Innovation Lab and modular, learning spaces (AKA “Hives”) clustered inside.
Welcome to what may be Harvard’s greenest roof—there are other buildings with larger solar installations, other green roofs, and additional beehives on several dorms and academic buildings but we know of no other rooftop at the University that is home to all three.
Originally constructed in 1964 as studios for WGBH-TV, Batten Hall was renovated and certified LEED Gold in 2011, transformed by the HBS Operations team as part of the University’s commitment to sustainability and combating climate change. Visitors and students do not, typically, have access to the roof, so the Office for Sustainability partnered with HBS to give our community a virtual photo tour of the green roof, beehives, and solar PV installation that have been installed.
Walking up the stairs to the second floor of the Batten Hall Hives, a large window provides an outlook to the green roof and beehives.
HBS has five green roofs across campus. Batten was the fourth installation and is the only “intensive” green roof at HBS with eight inches of soil, allowing for more robust plantings. This provides an ideal landscape for tall flowering perennial plants such as Black Eyed Susans, Echinacea, little lanterns, lavender, and heather. A total of nineteen different plant species grow here, planted in clusters as they would occur naturally in the wild, and flowering at different times throughout the year.
Not only are green roofs excellent for storm water management (absorbing up to 70% of rainfall and preventing runoff into the Charles River and sewer systems, thereby reducing concentrations of phosphorous and nitrogen from entering the water ways), but green roofs can also reduce Heat Island Effect and building energy consumption, by serving as an effective roof insulator.
Tens of thousands of Italian honeybees also make their home on the Batten green roof. To enhance the ecosystem of the HBS campus and surrounding community, a group of HBS Student Sustainability Associates (SSAs) working with HBS Operations arranged for the installation of two beehives in May 2015.
Bees act as a natural fertilizer, increase biodiversity, and make fresh honey that can be used at HBS. The hives, which both have plexi-glass walls for observing bee behavior, also act as an educational opportunity for students, faculty, and staff. Maintenance of the beehives is administrated monthly by Best Bees, a Boston-based non-profit dedicated to researching and advancing bee health.
The 113 kW solar PV system generates approximately 19% of Batten Hall’s annual electricity needs, instead of that electricity coming from the grid.
Groups of solar panels are strung together and connected to an inverter, of which there are five for this system. The inverter converts the DC (direct current) power generated by the panels to AC (alternating current) power, or electricity that can be used by the building.
There are four more solar PV systems installed at HBS, on the roofs of Shad, Tata, Morgan and Travis Hall, totaling around 300 kW. In total, over 1 MW of solar PV capacity has been installed by Harvard University across its Schools and campuses.