Pollution above Victoria Harbor in Hong Kong this month. (Jerome Favre/EPA-EFE/Shutterstock)

The experience of walking under thickly polluted skies on a trip to China in middle school remains vivid years later in Catherine ­Xiang’s memory.

Now 17, she has become an environmental advocate. She is troubled by sea-level rise and was dismayed by the decision to withdraw the United States from the Paris climate accord. She belongs to her Northern Virginia high school’s environmental club and plans on studying environmental engineering in college.

“I didn’t want the future to be like that. I wanted to keep blue skies and stars,” she said. “We should pass down an intact environment to the next generation.”

The Oakton High School student is far from alone in her fears about the planet’s future. Millennials and members of Generation Z acknowledge in greater numbers than their forebears that humans contribute to climate change. In recent years, high school students across Fairfax County, Va., have lobbied local officials to install solar panels at schools — a movement that struck success when the Fairfax County School Board approved plans in January to install the panels at three schools.

Weeks later, county officials decided to evaluate 200 buildings, most of which are schools, to determine whether they, too, could be suited for solar technology.

School Board member Pat Hynes (Hunter Mill) said the school system has a responsibility to help protect the world into which students will graduate.

“It’s our responsibility,” she said. “We serve children, and we’re already feeling the effects of climate change.”

It’s too early to say when solar panels will be mounted on school buildings in Virginia’s largest school system. But Fairfax’s initial embrace of solar energy coincides with growing momentum across the state. Drawn by the potential cost savings, environmental benefits and educational opportunities, school systems from Northern Virginia to Richmond to rural districts have explored or moved toward solar energy.

In Middlesex County on Virginia’s Middle Peninsula, where impressive waterfront homes belie a cash-strapped school system in which 41 percent of students are economically disadvantaged, affordability factored into the shift to solar, said John B. Koontz Jr., a member of the Middlesex County Board of Supervisors.

The 1,125-student school system is expected to save $50,000 a year initially from the solar panels that power the district’s elementary and middle schools. Those savings are expected to increase over time. Solar panels are expected to be installed at the system’s high school by the end of summer.

“All of us are telling the same story, all trying to deal with budgetary challenges,” Superintendent Peter M. Gretz said. “This is just such a no-brainer.”

Devin Welch, chief strategy officer of Sun Tribe Solar, the company that installed the panels in Middlesex County, called the project a way for the school system to “meet their energy needs and support their environmental values” without costing taxpayers.

School systems generally sign contracts called power purchase agreements with developers that pay most or all of the cost to install the solar systems, according to the Solar Energy Industries Association.

In return, a school pays the developers for the power that is consumed, which is typically less than what a utility company would charge. The developer profits from those payments and can reap federal tax credits.

More Virginia schools have sought solar energy in recent years because of the availability of those agreements, said Erik Curren, chief marketing and business development officer with Secure Futures Solar, a company that installs solar energy systems.

“Virginia was a tough state for schools to go solar in the past before power purchase agreements were allowed,” he said. It’s now really opened things up for K-through-12 school divisions, and we’ve seen a huge increase in interest.”

Two public schools in Arlington County have solar panels, and installations are planned at five more schools, a move expected to save $4 million in electricity costs over 25 years, according to the Northern Virginia school district.

Cathy Lin, energy manager for Arlington Public Schools, said the system is factoring energy efficiency into the design of new schools and called sustainability part of its “core mission.”

Sustainability was built into the design of Discovery Elementary School, which opened in 2015. Solar panels are planted on the Arlington school’s rooftop, and a geothermal-well system heats and cools water. The building produces more energy than it needs, allowing it to share power with nearby schools.

Emma Layton, a senior at W.T. Woodson High School in Fairfax, said there is more the school system can do to curb its impact on the environment, such as reducing carbon emissions from its bus fleet.

Layton, president of Solar on the Schools, the club that lobbied for solar panels in Fairfax schools, said climate change is a serious concern among her peers. The student club advocated with the Sierra Club and the Faith Alliance for Climate Solutions, a Northern Virginia group that seeks to address climate change, for the solar panels.

“Climate is something that affects everybody. It doesn’t matter what your background is or what your moral values are,” the 17-year-old said. “Nobody wants to see the world that we’re going to inherit be polluted and trashed.

Correction: An earlier version of this story reported that Middlesex County, Va., expected to save $50,000 a year on utility costs from installation of solar panels. That is the expected savings the first year. Savings in subsequent years are expected to be higher.