Hawaii will close its only coal-fired power plant on Thursday, an aggressive step forward in the state’s effort to transition entirely to renewable energy by 2045.
The AES power plant has been in use since 1992 on Oahu – the state’s third largest island and home to its capital Honolulu – and is responsible for as much as 20% of the island’s electricity.
But it also emits 1.5m metric tons of carbon dioxide each year, making it one of Hawaii’s main greenhouse gas emitters, according to Shannon Tangonan, spokesperson for Hawaiian Electric.
The closure of the plant came after Hawaii lawmakers approved legislation in 2020 effectively banning coal for electricity production by the end of this year. The AES corporation’s 30-year contract with Hawaiian Electric was set to expire this year.
Hawaii has long been known for its commitment to renewable energy. In 2015, it became the first US state to pass a law directing all electricity to come from renewable energy sources. Since then, nearly two dozen states and Washington DC have set similar goals, including New York, which is working toward zero emission electricity by 2040 and Rhode Island, which is working toward 100% renewable energy electricity by 2033.
“It’s a major milestone,” said Scott Glenn, Hawaii’s chief energy officer. “It’s our end of the use of coal in Hawaii after 150 years.”
In recent years, state officials have launched or initiated the development process on a variety of renewable energy projects, including the use of solar panels and battery storage facilities. The state has at least 14 solar, battery or geothermal projects set to open by 2024. Many of the projects on Oahu were expected to start running close to the time the power plant closed, but supply chain challenges and rising costs have caused delays, Tangonan said.
In July, the Mililani I Solar on Oahu came online. The large-scale solar and battery project has provided 39 megawatts of power during peak times, she added in explaining one of the renewable energy investments.
But the transition away from the coal power plant won’t be completely free of fossil fuels. Depending on the island, Hawaii still relies in part on oil from outside the US. On Oahu, the coal generation will be replaced at least in part by oil initially, Tangonan said.
The replacement means that electric bills for Hawaii residents, which already have a history of being higher than the mainland US, are expected to increase on Oahu by about 7% or $15 for an average resident.
“It is really unfortunate that we are having to rely on oil for a short period of time to transition from coal to the solar and battery projects,” Glenn said. “[But] it underscores the whole reason we need to make this change. Because oil is incredibly volatile. And we have to pay for it in a way that you don’t have to with solar battery.”
He said the state is expected to close some of its oil power plants in the coming years, including part of the Waiau power plant on Oahu.
Sandra Larsen, market business leader for AES in Hawaii, said the company supports the shuttering of its coal power plant and is now working on six renewable energy projects across the state’s four island counties. One of its projects, Kuihelani, is expected to generate power for about 27,000 homes on Maui.
“The coal plant was needed to help stabilize Oahu’s electricity rates and the economy … 30 years later, it’s time to move on,” she said.
Glenn did point to serious concerns about what would happen to the workers at the coal plant once it was closed.
AES has helped the majority of the plant’s more than 40 full-time employees transition to renewable energy positions, while providing training to help them move into the clean energy job market, Larsen said.
Glenn said he expects the shift away from coal and the state’s increasing reliance on renewable energy will lead to lower energy prices and more stable and predictable costs, but also less money sent overseas.
“The idea is that as we switch to renewables, and we have more predictable electric bills, and we’re bringing equipment to Hawaii to make electricity for us, rather than things to burn into electricity, then you started to keep more and more money at home,” he said. “We’re investing in ourselves. We’re building up our capital to be more independent.”
