The months-long, record-breaking heat wave that has caused spikes in Maui’s electricity use underscores why the island — and the state as a whole — has such ambitious renewable-energy goals.

Electricity use in July jumped 13% from the same month last year with average power bills up $24 to $224 per month, according to Maui Electric Co., which attributed much of the increase to air conditioning.

Maui relies overwhelmingly on MECO’s two oil-fired plants, in Kahului and Maalaea, but two new solar projects in the works — one approved, one facing community opposition — promise to push the island closer to the state’s goal of meeting 100% of Hawaii’s electrical energy needs through renewable sources by 2045.

These sources include a mix of waste-to-energy, biomass, geothermal, hydro, wind, biofuels and solar, both utility-scale and rooftop photovoltaic systems, all of which would help reduce Hawaii’s dependence on imported fossil fuels and lessen its impacts on climate change.

Maui County, including Molokai and Lanai, has already surpassed the state’s intermediate goal of 30% renewable energy by 2020, hitting 38% in 2018, mostly from wind power.

By comparison, Hawaii County produces 44% of its electrical energy from renewable sources — highest of the HECO-powered counties — and Oahu was lowest at 22%. (Kauai’s nonprofit Kauai Island Utility Cooperative, which set a goal of at least 70% renewable energy by 2030, reports that roughly 55% of the electricity generated on the island comes from solar, hydropower and biomass.)

In August, HECO, parent company to MECO, began soliciting projects to generate an additional 900 megawatts of renewable energy statewide, including 135 MW on Maui. The announcement to attract developers marks Hawaii’s largest effort to procure renewable energy to aid the transition from fossil fuels to “cleaner” sources, the utility said.

Proposals are due Nov. 5, with finalists to be named in May and contract negotiations to follow.

HECO’s first procurement ended in 2018, and the state Public Utilities Commission has approved seven of eight project contracts submitted from that effort. The seven contracts represent about 260 MW of renewable energy paired with nearly 1,100 megawatt-hours of energy storage, primarily through lithium-ion batteries.

All eight of the projects were solar projects paired with battery storage, and PUC officials believe that will be the case the second time around, even on Maui, where wind dominates.

Solar projects shine

In 2018 Maui received a little more than 23% of its electrical energy from utility- scale wind farms and 13.4% from rooftop photovoltaic systems connected to the MECO grid. The major wind-power generators are Kaheawa Wind I and II on the ridges above Maalaea and Auwahi Wind near the island’s remote southeast coastline.

But with the falling costs and increasing efficacy of photovoltaic panels, Maui and the rest of the state are poised to rely more heavily on solar as the future of electrical energy generation.

“Of the first round of projects, all of the ones that we selected in the final group were solar — actually, solar paired with (battery) storage,” said PUC Chairman Jay Griffin, even though developers were free to choose which type of renewable energy to pursue.

The second phase of renewable-energy project development on Maui will replace the 37.6-MW, oil-fired Kahului power plant, which is set to be retired by the end of 2024. The Maalaea plant generates 212.1 MW.

The two Maui projects that came out of HECO’s first procurement effort include the 60-MW Kuihelani Solar project on 500 acres in Central Maui by developer AES Corp., with an estimated completion date of 2021. (The same developer has been embroiled in community protests over construction of its Na Pua Makani Wind project in Kahuku and has other PUC- approved solar projects planned for Waikoloa on Hawaii island and in West Oahu.)

The second is the 200-acre, 15-MW Paeahu Solar project on Ulupalakua Ranch land above Wailea by developer Innergex. That project is still under review by the PUC and is being met with resistance from nearby residents.

Rooftop rules the roost

Utility-scale projects contribute a small fraction of the solar energy being produced in Hawaii, with home rooftop photovoltaic or PV systems generating the largest load.

In fact, Hawaii leads the country in the percentage of homes with rooftop solar panels at 19%, according to HECO. There are about 80,000 of these “customer- sited” PV systems in Hawaii — over 12,700 of them on Maui — connected to the HECO grid.

This is in no small part due to incentives such as HECO’s Net Energy Metering program, which began in 2001 and helped install over 60,000 systems until it was retired in 2015. The program allowed participants to feed electricity into HECO’s power grid and collect credits that could be applied to future charges from electricity taken from the grid.

The proliferation of customer-sited PV systems has led to an ongoing effort by HECO to modernize its grid to accommodate further expansion of customer-sited systems and make use of more advanced technology.

Despite HECO’s push for more utility-scale projects, some experts and environmental groups say rooftop PV systems that allow for “distributed generation” — the term for when electricity is produced on a small scale near the point of use instead of from a centralized power plant — are the best option for the future.

One reason is their ability to reduce widespread power outages, since they allow the formation of “microgrids” in which homes within a neighborhood are connected through small, mostly self-sufficient power grids.

“Distributed is better because it’s more local, and if you have a breakdown or something, it’ll only affect a few houses or a neighborhood rather than a whole island,” said Rob Weltman, chairman of Sierra Club Maui, who has been involved in discussions regarding Maui’s renew­- able-energy future.

Rooftop PV panels have the additional advantage of not requiring the large acreage needed for utility-scale solar farms, which can be unsightly.

Is bigger better?

The Pono Power Coalition, formed by a group of residents, is preparing to challenge the 15-MW Paeahu Solar project in a contested case hearing in December before the PUC. The residents argue the project will be detrimental to the environment and community, and that it should be moved away from where people live.

CarolAnn Barrows, director of the coalition, has produced a petition with the signatures of about 900 residents who oppose the project. She said Paeahu Solar is going to be 200 feet from her property and near a residential neighborhood.

“There’s basically no one who’s for this except for the proponents and their paid consultants here,” she said.

Innergex told the Honolulu Star-Advertiser the company is planning design changes to mitigate some of the residents’ concerns.

“Innergex’s solar project is coupled with a battery energy storage system which will provide significant value to the Maui electric grid,” said Eddie Park, the developer’s business development manager, in a statement. “We have heard concerns of several members of the Maui Meadows neighborhood raised at our community outreach meetings and with the PUC. … We have committed to design changes and, where possible, will be mitigating other concerns as the project moves through the design phase.”

Although the Pono Power Coalition’s goal is to move the solar farm, Barrows believes utility-scale solar projects, in general, will become obsolete because of the growth in rooftop systems and distributed generation of electricity.

“All of the experts in renewable energy are saying that the near future of renewable energy — and we’re not talking 50 years, we’re talking five to 10 years — will be distributed nano- and microgrids, not these huge solar power stations or wind farms,” she said.

John Cole, assistant specialist for the University of Hawaii’s Hawaii Natural Energy Institute, which conducts research on sustainable-energy technologies, sees the need for a mix of rooftop and utility-scale solar-power sources.

“Distributed (generation) is a great opportunity for a lot of different reasons, but it also presents the most challenges in the controlling of it,” he said. “It’s going to take a lot of investment” in improving the power grid.

Cole also said battery storage for individual homes isn’t yet a viable option for people who want to disconnect completely from HECO, citing limitations in battery capacity and inconsistent weather conditions.

For now, he said, staying connected to the grid may be the wiser option.

In an editorial board meeting with the Star-Advertiser, HECO President and CEO Alan Oshima said rooftop PV systems are needed to reach the state’s renewable-energy goals, especially in high-density areas like Oahu. But there are important reasons for staying connected to the grid, most critically to ensure its stability and safety for the entire island community and vital services.

“As more people leave the grid, the grid has to be supported by fewer customers,” he said. “The grid is essential for the economy, public safety, health, welfare and lifestyle.”

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HECO’S NEW PROJECT STATUS BOARD

Keep track of completed and pending renewable-energy projects statewide via Hawaiian Electric Co.’s new project status board available on its website.

The status board lists 17 grid-scale projects currently proposed or underway on four islands, ranging in size from a 2.6-megawatt solar and storage project on Molokai to a 52-megawatt solar and storage system in Kunia on Oahu. Altogether the projects represent 460 megawatts of renewable energy that is expected to come online by 2022.

Four categories are represented: under construction, approved by regulators, awaiting approvals and completed in 2019. The board will be updated as the status of projects changes.

The status board is available at hawaiianelectric.com/statusboard. Find additional information about HECO’s ongoing renewable-energy work and a list of resources at hawaiianelectric.com/clean-energy-hawaii.