Within the next two decades Hawaii public schools will need to produce as much renewable energy as they consume under legislation signed into law last week by Gov. David Ige.

House Bill 2569, now Act 176, requires the Department of Education to establish a so-called net-zero goal with respect to energy use and achieve it by Jan. 1, 2035.

The department, which operates 256 public schools, spends roughly $60 million a year on utilities. That budget could substantially rise as the state moves ahead with an initiative to cool 1,000 classrooms with air conditioning this year, although solar-powered air conditioners are being eyed for the project.

“This bill will save hundreds of millions in future operating costs that can be better spent in classrooms and higher paid teachers instead of utility bills,” state Rep. Chris Lee, who introduced the bill, said in a statement. “It also creates important accountability and transparency requirements for the $100 million the state has already given the DOE to cool classrooms.”

Lee, who says Hawaii is the first state to mandate that clean energy be used by all its public schools, said the measure also requires the Education Department to:

>> Expedite the cooling of all public school classrooms.

>> Submit an annual transparency and accountability report to the Legislature containing information about its progress toward the cooling of all classrooms and meeting the net-zero energy goal.

“Installing more efficient lighting, natural ventilation, and integrating innovative renewable technologies such as solar panels and batteries can help power schools, reduce electricity costs, and improve student performance,” the legislation says. “Powering new classroom air conditioning units with solar panels and batteries without the need to connect to the electric grid can also reduce costs by eliminating the need for costly campus electrical upgrades, and will not add significant new costs to public school electric bills.”

“Cooling the schools for the sake of our children and teachers is and will remain one of my highest priorities. This bill will expedite the process,” said Ige said Thursday.

The measure is similar to one passed in 2015 that requires the University of Hawaii system to produce as much energy from renewable sources as it consumes across its 10 campuses by 2035.