Hawaiian Electric on Dec. 11 announced its proposal to replace six aging fossil-fuel generators at its Waiau Power Plant with more efficient flex-fuel units that can be fueled with biodiesel, renewable gas or hydrogen will advance to the next phase of an energy procurement process overseen by the Hawaii Public Utilities Commission.
The 253-megawatt (MW) project was one of several selected as part of a competitive procurement progress for firm renewable generation on Oahu, according to Hawaiian Electric. The project still requires final approval by the PUC.
Hawaiian Electric plans to replace the six currently operating units with combustion turbines (CTs), which are similar to jet engines that turn turbines at high speeds to generate electricity. The company said the new units are intended to support generation resources, including variable energy like wind, solar and battery storage, when they are unavailable or unable to meet system demand. Each CT unit has approximately 42 MW of generating capacity and is smaller and more efficient than the steam boiler it will replace. The new units are also destined to quickly respond to fluctuations on the electric grid.
According to Hawaiian electric, the company plans to initially fuel the new units with biodiesel. The CT can also be fueled with renewable gas or hydrogen when those fuels become commercially available.
Waiau Units three and four, aged 76 and 73, respectively, are scheduled to be retired in 2024 and will be the first units to be replaced. The two initial CTs are expected to be placed into service in 2029. The other four units will be replaced in phases, with all units expected to be online by 2033, according to Hawaiian Electric.
Additional information is available on the company’s website.