HI HB2423

Requires diesel fuel sold in Hawaii for on-highway vehicles to contain at least 5% biodiesel by volume starting January 1, 2028, with renewable diesel allowed as a substitute if biodiesel supply is insufficient.

Defines biodiesel as liquid fuel from organic sources including agricultural residues, animal wastes, biomass crops, cooking oil/grease, oil crops, and sewage/landfill wastes that meet ASTM International standard D6751.

Establishes penalties of $2 per gallon of nonconforming fuel up to $10,000 per infraction for distributors or others violating the biodiesel requirements.

Requires the Department of Business, Economic Development, and Tourism to submit a comprehensive rollout plan to the legislature before the 2027 session and present it publicly at least 120 days before implementation.

Directs DBEDT to consult with the Department of Transportation during development and implementation of the biodiesel requirements to ensure operational coordination.