Two years ago, Gov. David Ige signed a law directing the state’s utilities to generate 100 percent of their electricity sales from renewable energy resources by 2045. That ambitious mandate gets a lot of attention, given Hawaii’s ranking as the most petroleum-dependent state in the nation. Another law, signed during the same ceremony, sets a net-zero energy target date of 2035 for the University of Hawaii system.

With that breaking-even status, the university would produce as much energy as the system consumes. The law’s commendable win-win aim is to “maximize student tuition savings by establishing long-term commitments to reduce energy use” at UH campuses.

Last week, UH and Hawaiian Electric Companies (HECO) officials announced the start of a collaborative effort to develop a “green tariff” initiative. Subject to Public Utilities Commission approval, the tariff would allow for the development of renewable energy resources, such as a solar farm, on UH land. If projects are able to succeed in providing renewable electricity at lower rates, HECO intends to make the tariff available to similar institutions.

Unlike the troubled Green Energy Market Securitization (GEMS), which charges Hawaii ratepayers a $1.50 “Green Infrastructure Fee” on monthly electrical bills, the green tariff’s charges would apply only to participants. That’s a relief to know.

GEMS was created four years ago to serve as a financing program to provide low-cost loans to those who cannot afford the upfront costs of projects such as rooftop solar systems. But even as the state legislation was in the works, the marketplace was changing. Private companies were starting to offer similar loans. And solar systems started outpacing the ability of Oahu’s grid to use the power. The saturation prompted utility concerns and a slowdown in new installations.

Even so, in 2014, the state sold $150 million in GEMS bonds for that original purpose, and was to have lent that money by the end of November 2016. It didn’t. Earlier this year, the program was seeking a course correction after having lent only about 2 percent of its funds while $33 million in interest on the bonds is being repaid by Hawaii ratepayers via the monthly fee.

Plans for the green tariff must be carefully vetted to avoid money- losing snags. In addition to its net-zero deadline, the UH has a stretch goal of achieving 50 percent “carbon zero” (no net release of carbon dioxide into the atmosphere) within 18 years, and is shooting to be carbon neutral by 2050.

Among the campuses making clean energy strides is UH-Hilo, which is leading the system in sub-metering, bi-level lighting and energy requirements in design contracts. Its PV array, which serves a student center, an academic facility and a performing arts center saves the university about $300,000 a year in electricity costs.

Hawaii’s electricity generation is dominated by fossil fuels, which emit carbon dioxide when burned and contribute to environmental problems such as global warming. And due to the continued costs tied to importing most of the energy used throughout the state, ratepayers shoulder the highest prices nationwide — more than twice the U.S. average.

With the 2045 clean energy law in place, utilities statewide will likely expand solar, wind and biofuel projects. HECO expects private solar systems to more than double by 2030 to 165,000 from the 79,000 now in use across its territories. Such an aim is needed to help the state rebound from costly losses linked to Hawaii’s move in 2015 to end its net-energy-metering policy, which credited customers the full retail rate for excess solar energy sent into the electrical grid.

In a statement last week, UH President David Lassner said reducing “both our dependence on fossil fuels and our utility bills is an essential part of fulfilling our leadership responsibility and commitment to the future of our students, our university and Hawaii.” He’s right. Amid stops and starts in recent years, the transition in the works to a fuller, homegrown renewable portfolio for the electricity sector promises to better the islands’ economy, environment and energy security.