Hawaiian Electric proposes replacing aging fossil-fuel units at Waiau plant

Hawaiian Electric is looking to replace six aging fossil fuel-powered generators at its Waiau Power Plant in Pearl City.

The company has proposed to replace them with smaller, more efficient, and fuel-flexible units, which can run on multiple fuels, including biodiesel and potentially hydrogen if it becomes commercially available in the future.

Unlike traditional steam generators built to run continuously and take hours to power on, the new units are designed to respond quickly to changing needs on the grid. That allows them to effectively fill the gaps when variable resources like solar and wind aren’t available. They can run cleaner, quieter, more efficiently and operate less frequently than the existing units.

The company submitted the proposal in April, as part of a competitive procurement, to state’s Public Utilities Commission (PUC), which will make the final determination. The Hawaiian Electric proposal and any generation proposals from other developers will be evaluated on price, technology, community benefits and other factors, with the review and final selection overseen by the PUC and an Independent Observer. There is no guarantee the Hawaiian Electric proposal or any other proposal will be selected in the competitive procurement or approved by the PUC. The final awards are expected to be announced in October.

“This proposed project represents the most impactful transformation of our generation infrastructure in decades and supports the critical need for reliable, 24/7 power that is much more efficient and aligned with our renewable future than the technology it replaces,” Mike DeCaprio, vice president of power supply for Hawaiian Electric, said. “Some of these oil-fired boilers were built just after World War II and while they’ve served us reliably for decades, they don’t have the flexibility and fast-start capability we need with our expanding portfolio of solar and wind resources.”

DeCaprio added that there will be operational cost savings and minimal community impact since it is being built within the footprint of the 85-year-old Waiau facility and reusing much of the existing infrastructure.

The Waiau Units 3 and 4, built in 1947 and 1950, are scheduled to be decommissioned and removed over the next several years. Also, four additional units, built between 1959 and 1968, will be decommissioned and removed in phases through the end of the decade.

In-service dates for the first new units will begin in 2029 with other units to follow.