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Hawaii Gas receives approval from the PUC to make renewable natural gas from Honouliuli biogas

–Biogas from Honouliuli Wastewater Treatment Plant will generate revenue for the City–

HONOLULU – Hawaii Gas, the state’s only regulated gas utility, received approval from the Hawai‘i Public Utilities Commission (PUC) to install equipment to capture and process biogas from the Honouliuli Wastewater Treatment Plant. Hawaii Gas was awarded the contract from the City and County of Honolulu in July of 2016 after a competitive bidding process.

“Incorporating cost-effective renewable natural gas as part of our fuel mix is a key priority as we continue to do our part to advance Hawaii’s clean energy future,” said Alicia Moy, president & CEO, Hawaii Gas. “We look forward to pursuing similar projects that deliver renewable fuels to our customers and new revenue streams to the City. This is a win-win partnership for the residents of Honolulu and our customers.”

The Honouliuli Wastewater Treatment Plant produces about 800,000 therms of energy per year, which is currently not being utilized. By selling the biogas, the City and County of Honolulu will generate approximately $1.6 million of revenue per year.

“We are pleased that the project to turn wastewater gases into renewable natural gas is moving forward. This first-of-its-kind project in Hawaii will benefit the City financially and more importantly is equivalent to eliminating the need for approximately 15,000 barrels of oil and reducing greenhouse gases by the amount produced by 400 cars annually,” said Lori Kahikina, director of the City and County of Honolulu Department of Environmental Services.

The awarded contract expires December 31, 2024, with a provision to extend the term. Hawaii Gas will invest about $5 million in the infrastructure to process the raw biogas and to connect the Honouliuli Wastewater Treatment Plant to the company’s existing pipeline. The project is estimated to be operational by the end of 2018.


About Hawaii Gas

Hawaii Gas is Hawaii’s only government-franchised, full-service gas company manufacturing and distributing gas in Hawai‘i. Hawaii Gas manufactures synthetic natural gas, or SNG, for its utility customers on O‘ahu, and distributes liquefied petroleum gas, or LPG (propane), to utility, tank and bottled gas customers to all islands. Hawaii Gas is a wholly owned indirect subsidiary of Macquarie Infrastructure Company. For more information, visit


 City Procurement Process

  • The City & County of Honolulu issued a Request for Proposal for the Sale of Biogas from the Honouliuli Wastewater Treatment Plant (WWTP) on July 31, 2015. On July 28, 2016, Hawaii Gas received notification of the contract award.
  • The awarded contract expires on December 31, 2024, with the provision for an extension.

Biogas in Hawaii

  • Current biogas output at Honouliuli WWTP is estimated to be approximately 800,000 therms per year, which is currently not being utilized.
  • The 800,000 therms is approximately 2.8% of the total synthetic natural gas (SNG) demand for the island of Oahu.
  • 800,000 therms is the energy equivalent of approximately 15,000 barrels of oil or 575,500 gallons of diesel.

Biogas Capture and Purification Infrastructure

  • Biogas is produced at wastewater treatment plants and landfills when biodegradable waste is broken down through chemical reactions and by microbes, or as digested gas is produced inside an anaerobic digester.
  • After impurities are removed from the raw biogas, the end-product is a ready-for-market renewable natural gas (98% methane and 2% carbon dioxide) that Hawaii Gas will blend with the synthetic natural gas (SNG) in its pipeline.
  • The biogas purification equipment and approximately half a mile of pipe will be built at the Honouliuli facility and connect to the existing SNG pipeline.
  • The project is estimated to be operational by the end of 2018.
  • DMT Clear Gas Solutions, a global industry leader in waste gas capture and processing, is responsible for designing and installing the system at Honouliuli at a fixed project cost.



Alan Tang