DRESSED IN PASTEL pink and green for an early spring day, second-grader Katherine Cribbs was learning about energy on a virtual field trip—to her own school.

With a flurry of touch-screen taps, she explored the “energy dashboard” of Discovery Elementary in Arlington, Virginia. On her tablet, she swiped through 360-degree views of her school, inside and out. She clicked on icons embedded in the virtual classroom to learn about energy-saving features such as LED lights and super-insulated exterior walls made of concrete-filled foam blocks. Exploring the virtual school kitchen, she could read about how the lack of a deep fryer means less energy is needed for venting grease from the air. Another swipe whisked her up to the school’s roof, where about 1,700 solar panels spread out before her.

After a few minutes, she looked up from her computer to explain her progress in a confident voice that rose above the second-grade din. “I learned that our solar panels rotate,” she said. “So, wherever the sun moves, the panels go, too.”

In addition to this virtual tour, Discovery’s dashboard displays, in real time, the school’s energy generation. And in colorful bar graphs and pie charts, it also tracks energy use—broken down by lighting, plug load, kitchen, and HVAC. The tally reveals that Discovery generates more energy through its solar array than it uses over the course of the year.

Buildings that make at least as much energy as they use are called “net-zero” (and “net positive” if they make more than they need). And nationwide, K-12 schools are leading a fledgling “net-zero” building boom that has grown from a few proof-of-concept structures a decade ago to hundreds of buildings completed or under-construction.

Read more: SOLAR PANELS POWER NEW SCHOOLS—AND NEW WAYS OF LEARNING