Hawaii is staking out important policy turf in its latest commitment to green energy, pledging to invest in improvements that will save enough in energy expenditures to eventually recoup their cost.

It will advance Hawaii’s mission to become less reliant on oil-based energy — by wasting less of it and transitioning to more renewable sources.

It’s a promise that sounds wonderful in concept, when presented in the context of a high-profile meeting, but will take an extraordinary effort by the state and Honolulu governments to deliver.

The plan was unveiled last week at the Clinton Global Initiative America meeting in Chicago, an event hosted by former President Bill Clinton.

The investment commitment is for $300 million in upgrades to state and Hono-lulu county buildings, following an aggressive timetable.

All the work, which will be done according to performance-based contracts that need to show stated energy savings, is to be completed sometime in 2015.

The benefits sound terrific. Estimates are for 5,000 new jobs to be added to Hawaii’s economy over the course of the improvements being made, and for all the encouraging signs of a turnaround in the Hawaii’s fortunes, the work will be welcome to a construction industry that’s only started to heal. Industry officials say 20 percent of its workforce is still unemployed.

It’s a mammoth job list. The improvements are pegged for the 15 airports under the state Department of Transportation, the Department of Public Safety’s prisons and jails, 30 structures at the University of Hawaii at Hilo, the Honolulu Board of Water Supply and the city’s largest wastewater treatment plants and other locations.

Such improvements are certainly an essential ingredient in the success of Hawaii’s Clean Energy Initiative goals, first adopted under the administration of Gov. Linda Lingle.

The essence of the policy is to achieve 70 percent clean energy by 2030. The state achieves those benchmarks in two ways: by boosting Hawaii’s production of its own renewable energy to 40 percent of the total portfolio, and to boost energy efficiency by 30 percent.

All of this adds up to a necessary shift away from the islands’ long-standing dependence on imported fossil fuels, with the objective of reducing carbon emissions and boosting the local economy. All that money spent on fuel imports leaves the state and does little for Hawaii’s own business vigor.

The green-energy fields have been a major source of job growth in recent years. The hope of this pledge is that it will result in jobs for engineers, building operators, equipment installers and building maintenance operators, as well as the shorter-term construction work. And the ripple effect of circulating more money here could produce more jobs, according to the rosy assessment of its supporters.

However, a bit of a reality check has come from Karen Nakamura, the chief executive officer of the Building Industry Association of Hawaii. The jobs may not materialize, she said, unless the state moves on the engineering work that must be done to get the projects sized up and the contracts procured quickly enough.

Her suggestion: Subcontract with private engineering firms rather than rely on in-house planning. It’s certainly worth considering, although the State Energy Office has promised technical assistance and more backup help.

A detailed plan on how this can work will be needed if the state Legislature is to approve funding for all this, given that the state is fronting a significant amount of its limited resources to achieve savings in the long term.

Additionally, energy officials will need to coordinate permitting processes through state and county planning agencies so that work isn’t bogged down in bureaucratic delays.

On the whole, Hawaii’s taxpayers should applaud the intent of this clean-energy drive. Performance-based contracts will provide some assurance that they will get the savings they paid for — and the government will need to meet a high bar for its own performance, as well.