A North Carolina coalition of parents, teachers and students has called on the state’s school districts to start using solar power amid a nationwide trend of schools adopting the renewable energy source.

North Carolina schools could potentially save millions of dollars on utility bills in the coming decades if they install solar panels, according to Hannah Mitchell of Repower Our Schools, a nonprofit organization that promotes solar installation in the state’s schools. But North Carolina is one of just five states that still have significant barriers to financing solar projects, including the prohibition of third-party financing for solar energy, Mitchell said.

"We've seen an increasing demand on the part of community members, parents and teachers wanting renewable energy options in our schools," Mitchell said. "If we were to have changes to statewide policy like explicit legislation of third-party energy sales, the schools could save a lot."

At least 26 states plus Washington, D.C., and Puerto Rico allow third-party financing for solar power, according to data from DSIRE, a renewable energy information group operated by the North Carolina Clean Energy Technology Center at N.C. State University (NCCETC).

Third-party financing is the primary method U.S. schools are using to go solar, experts say, because it helps lower the upfront costs. With this financing, a customer leases the solar equipment and makes monthly payments.

Nearly 4,000 U.S. schools had installed solar panels by 2014, according to Steve Kalland, executive director of NCCETC. But he said North Carolina’s lack of third-party financing options means schools won’t receive the same savings.

Repower Our Schools commissioned NCCETC to research how North Carolina school districts Charlotte-Mecklenburg Schools (CMS) and Durham Public Schools (DPS) might benefit from solar energy.

With the allowance of third-party energy sales and upgrades to net metering policy, the nonprofit environmental group Greenpeace estimated that CMS could save $54.6 million and DPS could save $16.3 million over 25 years.

"In North Carolina, and in a very small number of states, its very challenging to do that because of the ban on third-party sales," Kalland said. "It's only utilities that are allowed to sell electricity to end users ... there may be other ways to get at school systems but it would probably entail either some kind of charitable mindset on the part of the utility or some other direct government subsidy to cover the upfront costs."

Because schools, like churches, are not tax-paying entities, they also do not receive the federal tax breaks that other commercial businesses and residents do when they install solar.

Financing solar energy for public institutions remains "one of the more challenging pieces of the puzzle in terms of the regulatory structure," Kalland said.

Industry trends suggest that more public institutions, including schools, will install solar energy panels in the near future. That’s possibly due to the lower cost of the alternative energy source, but also because of mechanisms like third-party financing, according to Henry Tsai, associate director at NCCETC.

More than 3,000 of the nearly 4,000 U.S. schools with solar energy installed the alternative energy source in the last six years, according to the nonprofit Solar Foundation. The group says the average cost of solar installation dropped by about 53 percent since 2010.

"Going solar is a major investment in time and capital, especially for public institutions," Tsai told Al Jazeera in an email. "To put it simply, one should always be looking at the interaction among the trifold of technology, policy and finance."