29 May Making The Grade
For schools, net zero energy design provides more than cost-saving benefits
Spring 2018 | Written by Jeff Harder
A look at the rise of zero energy–ready schools, and the publication guiding their future development.
In August 2017, when a once-in-a-century solar eclipse darkened the sun above Arlington, Virginia, students at local Discovery Elementary School found raw material for a math lesson. The newest incarnation of the kindergarten-through-fifth-grade institution, which became one of a handful of net zero energy schools in the country when it opened in 2015, features a digital energy dashboard created by the building’s engineers that measures how much energy the school consumes as well as how much its 1,710-panel solar array produces. Students looked at the data—solar generation dipped from 274 kilowatts of energy just prior to the eclipse to 53 kilowatts during the eclipse—and calculated the decrease in the school’s solar production. The 81 percent decrease in solar power generation, students learned, matched the 81 percent of the sun obscured by the moon at the height of the eclipse.
It’s a far cry from learning multiplication tables by rote. “Educators use the word ‘authentic’ because the students are experiencing it and seeing it for themselves,” says John Chadwick, assistant superintendent of facilities and operations for Arlington Public Schools. “They learn and understand it much more deeply than if it was some abstract exercise.”
Discovery Elementary is living proof of the net zero energy design concepts published within the newest Advanced Energy Design Guide for K-12 School Buildings, released earlier this year. The guide—funded by the Department of Energy and developed by the U.S. Green Building Council (USGBC), the National Renewable Energy Laboratory, ASHRAE, the Illuminating Engineering Society, and the American Institute of Architects—is the first such publication to provide specific recommendations for zero energy–ready buildings, bringing benefits to a wide audience that go well beyond lower energy bills—as Discovery’s celestial arithmetic lesson proves.
Above: Discovery Elementary School is an all-electric building that fully offsets its energy use through the generation of clean, renewable solar power. Photo: Lincoln Barbour Photography
Today, building owners can say, ‘I want a LEED-certified building,’ and even if they don’t fully know what that means, they know they can hire someone who does understand and will design one,” says Paul Torcellini, principal engineer at the National Renewable Energy Laboratory and project committee chair for the K-12 schools design guide. “Now we’re moving into an era where a building owner can also pick up this design guide, wave it around to their design teams and contractors, and say, ‘This is what I want, and this is the performance I expect to get.’”
Schools are at the vanguard of net zero for a host of reasons, Torcellini says: They’re typically owner occupied, they’re in virtually every community, and they’re generally three stories or fewer with ample roof space. By some estimates, K-12 schools in the United States spend $8 billion or more on energy bills each year, the second greatest expense behind educator salaries—and cutting energy consumption by 25 percent could free up $2 billion to reinvest in education.
While previous iterations of the design guides—two of which Torcellini helped produce—aimed to reduce buildings’ energy consumption by 30 and 50 percent, maturing technologies (like low-power laptops replacing energy-sucking desktops), ever more stringent building codes, and ever more adept contractors have made buildings that balance renewable energy production with energy consumption (or that produce an energy surplus) a newly viable ideal. “Thinking of buildings as energy exporters, or able to provide more energy than they take, is a paradigm shift,” says Torcellini. “That’s important because buildings use material and land resources—all these things that LEED looks at—and the question is, what good can they do in return? One way is that they can produce more energy than they use and send it to others.”
Above: John Chadwick is the assistant superintendent of facilities and operations for Arlington Public Schools.
Above: Students conduct real-time experiments in the solar lab using the school’s building dashboard system.
Above: Discovery Elementary School has ideal solar orientation. The north side of the school features sun shades and panels which use playful arrangements of cool colors, echoing the natural expression of moss that grows on the north side of trees.
The 226-page guide focuses on policies, design strategies, and practical advice—from modeling energy performance to managing plug loads, writing RFPs to optimizing daylighting—for schools to drastically reduce energy loads to a minimum that a renewable energy system can reliably cover. “The basic principles of saving energy still have the biggest impact,” Torcellini says. They’re also the most easily transposed from one location to the next, regardless of the renewable energy incentives available or absent in a given school district. Zero energy design is remarkably affordable. (Discovery Elementary came in $1 million under the allotted budget.) And the focus on actual performance leaves little room for confusion. “You look at your utility bill at the end of the year, and you either hit the target or you didn’t,” Torcellini says. “Zero energy is zero energy.”
Net zero-ready schools fit into a variety of locales and circumstances. The Friends School of Portland, a 15,000-sq-ft private, pre-K through eighth-grade school in rural Maine, is just one example of a school working toward zero energy. “One of the Quaker values we live by is stewardship, so it was a priority to design our new school to reflect that commitment,” says Jenny Rowe, head of the school.
The Friends School of Portland—which served as one of the case studies used to develop the design guide—features an airtight building envelope and solar energy acquired through a power purchase agreement, and construction was an exercise in frugality: construction costs (not including site work) totaled $196 per square foot—far less than costs that, in the Northeast, can run north of $325 per square foot. The school is a work in progress: Energy models that didn’t account for LED parking lot lighting and a heavier-than-expected burden on heating and cooling systems mean the school consumes 60 percent more energy than it produces. Still, that’s less a measure of failure than a jolt of motivation. “We are speaking with potential donors about adding more solar panels in order to reach net zero—we haven’t given up on that goal,” she says.
At Discovery Elementary School, Chadwick—who contributed to the Advanced Energy Design Guide for K-12 School Buildings as a project committee member—said he expected a net zero school to weave together teaching, learning, design, and sustainability into an environment where as many as 630 students love to learn. Those expectations have been exceeded, he says, with a design for a three-level, 98,000-sq-ft, north-south oriented building—ideal for daylighting while minimizing solar gain—terraced into the grade. Along with the 496-kw solar array, 150 geothermal wells dug under a ball field service a distributed heating and cooling system inside.
In its first year, Discovery Elementary produced 18,600 kWh more energy than it consumed. (Real-time and historical data from the energy dashboard is available to all, from iPad-toting students in classrooms, to visitors navigating the oversized touchscreen in the school’s lobby, to anyone who types http://220.127.116.11 into their web browser.) “It is by far our [district’s] easiest building to maintain and operate,” Chadwick says. It saves roughly $100,000 in energy costs each year, enough to pay two teachers’ salaries. Another net zero-ready elementary school in the district is under construction.
Above: Inside classrooms, flexible details such as foldable partitions, retractable garage doors, and various furniture offerings support teacher collaboration and cross-pollination. Throughout the school, one-to-one technology enables research and collaboration to happen anytime, anywhere.
Above: Paul Torcellini is the principal engineer at the National Renewable Energy Laboratory.
Beyond making for more engaging math problems, there have been other happy unintended consequences attributed to the design. A month after the school opened, Chadwick says, a phenomenon emerged: Instead of heading home after late-in-the-day doctor and dentist appointments, students regularly insist that their parents to bring them back to class—a testament to the teaching as well as the environment, Chadwick says. And with students still navigating their formative years, the influence of the school environment has only begun to emerge.
“Our Energy Dashboard engages students in authentic learning. Math and science inquiry lessons are more exciting when data is about their school. Overall, the sustainability features of our school have greatly impacted our students,“ says Erin Russo, principal of Discovery Elementary. “We are growing green leaders who truly care about their school and the natural environment. Students feel challenged to make the world a better place and when we have visitors they are excited to explain how their green building works and the green practices we have set up.”
“You’re training them to be environmentalists at a very early age,” Chadwick says. “They [become] much more aware of these issues. They become advocates. And in many ways, they call the adults to task.”