The multiple failures of large-scale solar/battery projects in Hawaii is raising worries about the state’s ability to meet its ambitious goal of producing 100% of energy from renewable sources by 2045.

The latest bad news comes from South Maui, where the Paeahu Solar project was called off by Innergex Renewable Energy. It was the fourth failure of a utility- scale solar and battery storage project on Maui in five years — projects that were approved by the state Public Utilities Commission (PUC) and were deemed crucial to weaning the island off expensive fossil fuels.

“Maui is facing critical deadlines for bringing on new resources by the end of the decade and the loss of Paeahu and other projects is concerning,” said Mike DeCaprio, vice president of power supply for Hawaiian Electric.

And it’s not just on Maui. On Oahu, high costs and development delays contributed to the cancellation of two larger solar-plus-storage projects in Kunia: the 120-megawatt Mahi Solar project and the 60-megawatt Kupehau Solar project.

Does this mean that the naysayers are right, that the state’s renewable-energy efforts are too ambitious, or worse, an expensive waste of time?

Of course not. Weaning Hawaii off expensive imported fossil fuel, and replacing it with clean energy we produce ourselves, makes both environmental and economic sense, especially with the rest of the country heading in the same direction. But to get there by the 2045 deadline will require constant adjustments by policymakers to ensure that the transition moves steadily forward and, more important, remains affordable to the public.

Some of the blame for the failure of the projects has been placed on fallout from the COVID-19 pandemic, including supply-chain disruptions and inflation driving up costs. Solar industry analysts expect conditions to improve over time, as supply-chain problems recede and the Inflation Reduction Act (IRA) of 2022 kick-starts investments in clean energy manufacturing in the U.S. On the mainland, there already are signs of resurgence: S&P Global Market Intelligence reports that utility-scale solar energy installations in the third quarter of this year increased by 107% over the previous year.

Still, the recent failures here reflect the difficulty of planning large-scale solar projects in Hawaii, where land is scarce and other costs are much higher than on the mainland — and when unexpected developments can render obsolete cost and construction assumptions. Project developers and HECO have tried to save their projects by seeking PUC permission to modify power purchase agreements by extending construction deadlines and increasing the price of energy generation. The PUC has rightly been skeptical of price increases that would saddle ratepayers with higher energy costs for years to come.

According to HECO’s Integrated Grid Plan, 63% of Maui’s electricity came from nonrenewable sources in 2022. By 2030 — just seven years from now — HECO wants to reduce that number to 9%, with solar making up the lion’s share of energy generation at 52%, and reaching 56% by 2045. It’s a tall order, and getting taller. HECO must retire its Kahului Power Plant by 2028 to meet environmental regulations. And its Maalaea Power Plant may not last beyond 2030 due to a lack of replacement parts for its generation units.

It seems clear that the state needs to bulk up on Plan B: putting solar on every available rooftop, with energy coming from many smaller generating systems. Expanding other sources such as wind power also will be crucial to success. So will conserving energy. And to keep costs manageable, HECO and the state must aggressively pursue more federal funding, from the IRA and and other sources.

The road to a fully renewable future may not be straight or smooth. But if we stay on it, we’ll get there.