Brock Environmental Center Vindicates Onsite Wind Generation
June 6, 2016
The Living Building Challenge (LBC) has a strict ban on greenfield development, with one exception. It allows for buildings in previously undeveloped—even ecologically sensitive—locations when they are there to help people learn about the place. As a facility that’s all about caring for and teaching people about nature, the Chesapeake Bay Foundation’s Brock Environmental Center fit that bill perfectly and achieved LBC certification in May 2016.
Going the extra meter
What does it take to achieve such a goal? “Dedication” is the word that comes up most often, but it hardly seems adequate to the actual experience.
Design and construction were no picnic, with frequent energy modeling to fine-tune every aspect of the electrical, mechanical, and enclosure systems. And like other LBC project teams, the designers and contractor struggled to vet every single product against the LBC Red List and transportation distance constraints. (See Take Control of Your Materials: Four Empowering Lessons from Teams That Beat the Red List.)
But what makes this and other LBC projects stand out in terms of commitment is how closely they are watched during that critical 12-month performance period. Project architect Greg Mella, FAIA, of SmithGroupJJR describes getting a nightly email from the building management system detailing the building’s energy use for the past 24 hours and checking it every day for anomalies. That vigilance paid off: the photovoltaics and wind turbines generated more energy than was predicted and a whopping 83% more energy than the building used during its first year.
The energy used in the building came in at just over 14 kBtu/ft2·year, about 80% less than the average building of its type. Overall, this energy use is slightly less than the energy models predicted, but the details show greater variation: lighting came in at 39% less than predicted because the lights are mostly off rather than dimmed to 10% output as modeled. Fans and pumps are using more energy than predicted, however. One reason for this is that the fans in the mini-split (VRF) heat pumps run continuously, which wasn’t anticipated.
“My favorite part of operating Brock is that each day is a new learning experience, and being able to use those lessons to educate our guests,” says Chris Gorri, Brock Environmental Center manager for the Chesapeake Bay Foundation. You don’t have to be onsite to monitor the building’s performance, however: its Lucid Energy Dashboard is available online.
Swimming to utopia
It’s not easy to supply one’s own potable water and treat wastewater at the scale of individual buildings, which is exactly what officials at Virginia Beach Public Utilities tried to tell the Brock project team when they asked about permits to run their own waterworks for the 10,500 ft2 building (for more on building-scale water treatment, see Waste Water, Want Water.)
Many LBC projects are using municipally supplied water under a temporary exemption from the International Living Future Institute, which oversees LBC certification, but Brock is now the first LBC project to provide its own drinking water from rainwater with official sanction. Gorri was amazed at the amount of time and knowledge it takes to capture rainwater and treat it onsite to potable water standards. “If you would have told me a year ago that I would know so much about treating rainwater, I would have laughed at you,” he told BuildingGreen.
Blowing (more than) smoke
BuildingGreen has been skeptical of onsite wind energy as a power source for buildings (see The Folly of Building-Integrated Wind), but Mella suggests a rule of thumb for identifying sites with wind power potential. “If the wind frequently blows hard enough that it’s uncomfortable, you might have a good site for it,” he says. The two Bergey 10 kW turbines on this project generate about 40% of the onsite renewables at a cost of $0.38 per kWh (assuming a 25-year service life). The cost is that high mostly because anchoring the turbines in the coastal sands required multiple 110-foot-deep pilings.
The Bergey turbines spin on the horizontal axis, which is inherently more efficient than vertical-axis designs, and they are certified for performance by the Small Wind Certification Council. (BuildingGreen recommends avoiding turbines that lack this certification.) After they came online, they required adjustment to increase their maximum operating wind speed; winds onsite were so strong that the turbines were cutting out unnecessarily often.
Grand Central on the Bay
The location also made flooding an obvious concern, leading the team to incorporate a number of resilience measures, most notably raising the facility on piers to 14 feet above sea level.
For an organization dedicated to raising awareness of the need to “Save the Bay,” the best metric of success has been the tremendous visitor flow at the new facility—30,000 visitors in year one, according to the foundation. Some of these visitors came across the facility by chance—attracted, in some cases, by the wind turbines. Regardless of how they arrive, “there’s always a moment during a tour of the building when you see the light bulb go off in the group’s minds,” says Gorri. “They get it, they understand it, and they leave here inspired to do or change one thing.”