The state’s largest utility company now has an approved high-level plan to modernize electricity grids on Oahu, Maui, Molokai, Lanai and Hawaii island.

Over the next six years, Hawaiian Electric Co. and its affiliates expect to spend $205 million on items that include wireless smart meters, power quality detection sensors, devices that can turn off rooftop solar systems, and power outage management and notification technology.

The upgrade plan is intended to expand renewable energy generation, including more rooftop solar systems; improve service reliability; and provide flexibility to adapt to future technological breakthroughs.

The $205 million cost is estimated to increase the average monthly customer bill by 94 cents on Oahu, $1.93 in Maui County and $2.07 on Hawaii island over the six-year period. Kauai is not served by HECO.

HECO has been working for two years on getting a grid modernization plan approved by regulators. The company submitted what it initially called a “smart grid foundation” in March 2016, but the state Public Utilities Commission rejected that $340 million plan over concerns that included its cost-effectiveness, lack of vision detail, risk of obsolescence due to advancing technology and potential redundancies due to growth of distributed energy.

In August the utility submitted its new plan, which the PUC approved Wednesday.

“It is time to move beyond high-level strategies to build that backbone,” the commission said in its decision.

The three-member commission called the grid modernization plan a “holistic view of how Hawaii’s electric grid can evolve.”

Upgrades won’t be immediate. Specific pieces of improvements described in the plan need to be submitted for PUC approval, and that work is projected to include a “near-term road map” submitted by HECO by the end of next month.

The utility projects spending $6.5 million this year, $49 million next year and $32 million in 2020. The biggest year for expected spending is 2021 at $69 million. The last two years in the plan call for $28 million and $20 million in spending, respectively.

If the strategy is implemented successfully, HECO would be able to achieve 100 percent renewable energy generation by 2045, the PUC decision said.

The commission made its decision after public hearings and input from federal, state and local government agencies; private organizations; and individuals.

Substantial improvements were made to the plan based on stakeholder feedback, the PUC added.

Regarding concerns raised by some people about negative health effects from smart meters, HECO committed to explore wired communication alternatives for advanced meters for select customers.

“The fact that customers from across the state participated in the creation of this strategy along with technical experts and other stakeholders from Hawaii and the mainland is one of the reasons we believe it will be successful,” Colton Ching, HECO’s senior vice president for planning and technology, said in a statement. “Early on, the commission directed us to broaden our outreach efforts and as they noted in their decision, those efforts paid off with a much more customer-focused plan.”