Southeast sees surge in net-zero schools
At the request of nearby residents, Discovery Elementary School in Arlington, Va., was designed to hide its rooftop solar array. Photo by Alan Karchmer
A Virginia school’s recognition last month for its net zero energy status is part of a growing trend in the Southeast.
According to the New Buildings Institute, four of the five states with the most net zero energy schools underway in 2016 were in the South — despite low power rates and few policy incentives.
Ground zero for net zero schools is coal-rich Kentucky, where former Gov. Steve Beshear tapped federal stimulus money to offer incentives for schools to become more energy efficient.
In South Carolina, there’s a county system planning five net zero facilities. A North Carolina district has committed to building only net zero from now on.
And in Virginia, Arlington Public Schools is operating one of the nation’s largest net zero buildings of any kind.
“Net zero wasn’t even part of the (Arlington Schools) proposal,” Discovery Elementary School architect Wyck Knox told the Kendeda Fund before collecting an award at last month’s U.S. Green Building Council’s Green Schools Conference in Atlanta. “We looked at it, and said, ‘You know, we think that we can do this at net zero energy and still stay under-budget.’”
It helped that Knox, who practices at VMDO in Charlottesville, Virginia, was pitching his ambition to a system with a strong sustainability track record. At least five of Arlington’s schools have achieved LEED certification.
In its bid for the 98,000-square-foot project, VMDO presented Arlington with a choice. Either contract for a “net zero ready” building for $30.7 million, or contract for the same building but spend another $1.3 million on nearly 500 kilowatts worth of solar panels. Both bids were well below the system’s $36 million budget.
Turning a corner
Generally, a building meets the definition of net zero if, through a combination of efficiency and onsite renewable energy, it produces as much energy over the course of a year as it uses. If it produces more clean energy than it uses, it’s net positive.
In 2016, the feasibility of net zero K-12 schools seemed to turn a corner. The New Buildings Institute’s list of “verified” and “emerging” net zero buildings reached 332 projects in November — an increase by three-quarters over 12 months. Thirty-eight percent of those buildings were K-12 schools.
“We used to have arguments about whether it was technically feasible,” says NBI’s Amy Cortese. “That conversation is over.”
Cortese is careful to note that net zero (which NBI refers to as “zero net energy”) isn’t a slam dunk for more energy-intensive building types, such as hospitals. But schools — particularly elementary and middle schools — are a good fit for a number of reasons. They have predictable and relatively constant energy demand, they have large roofs suitable for solar panels, and districts have a long-term interest in reducing energy costs and possess bonding authority for big projects.
A building’s sustainable features can also offer up a teachable model for both the environment and technology. The most creative design teams draw out those themes by employing nature-based motifs and by engaging students with energy dashboards and observable systems.
“In many circumstances, (net zero) can be done for the same cost as a conventional building, and once they’re in place, they save every year on utility costs,” Cortese said.
The rules are changing
Once a project is approved, net zero designers typically follow a rule of thumb: Before sizing renewables, they do everything possible to cut their projected energy demand.
Discovery School’s designers studied the building’s orientation and massing to maximize passive solar. They created a tight envelope by using insulating concrete forms and, Knox says, through “an obsessive attention to detail.” They did a lot of energy modeling. They followed CMTA’s recommendation to heat and cool the building with 58 geothermal heat pumps, which effectively broke the school down into sensor-controlled zones — each serving about two classrooms.
The ultimate “customers” for any school are, of course, its students. Knox was acutely aware of that fact as he and his team designed Discovery Elementary. As a result, environmental awareness is reinforced throughout the building. Each grade’s classrooms are built around a common hallway with a way-finding motif built on broader and broader realms of nature.
At the front entrance, a spiffy, modern solar calendar tracks seasons. There’s even a Solar Lab, where students are able to interact with the school’s rooftop electric and water systems.
CMTA’s Devin Cheek is particularly proud of the school’s energy dashboard that tracks the energy production, energy consumption and the net of those two numbers. In addition to accessing it real-time from any computer, students can view the dashboard on a large-screen TV in the entrance lobby and on a waterproof version in the rooftop solar lab.
It helps that the dashboard consistently shows good news. Discovery’s performance since it opened in fall 2015 has exceeded expectations. This school year, both Knox and Cheek have taken to looking gleefully at the dashboard and proclaiming that Discovery’s 2016-17 school year could “blow net zero out of the water.” This year, the school is expected to save the district some $80,000 in power bills (compared to the typical Arlington elementary).
Similar stories at other net zero schools appear to be building momentum for the net zero movement.
Similarly inspired by a net positive school in Sandy Grove Middle School in Lumber Bridge, N.C., the Horry County, S.C., school board committed last year to five net positive projects: three new middle schools, an intermediate school and an elementary school. The smallest of those five schools — which are scheduled for completion this summer — will be 120,000 square feet.
“It’s much easier to do this on a new building,” said John Chadwick, assistant superintendent for facilities and operations at Arlington Public Schools. “The next frontier is how we can do it on an existing building.”
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