Renewable Natural Gas (RNG)

What is Renewable Natural Gas?

Renewable Natural Gas (RNG) is natural gas or methane produced from renewable resources such as wastewater treatment plants, landfills or by anaerobically digesting organic matter such as agricultural crops.

Renewable Natural Gas is an ultra-clean, low-carbon natural gas alternative. It is not a fossil fuel. Renewable Natural Gas is the naturally occurring gas generated by organic matter as it decomposes.

When organic matter decomposes or is anaerobically digested, it creates biogas, which primarily consists of approximately 60 percent natural gas and 40 percent carbon dioxide. Today, Hawaii Gas is working to increase the use of renewable natural gas in its business from wastewater treatment plants and landfills and from other renewable resources.

Renewable Natural Gas Plant
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Uses of Renewable Natural Gas

Renewable Natural Gas can be used for many of the same applications as natural gas. Renewable Natural Gas is a cleaner fuel as compared to the
1) oil and diesel now used to produce electricity  
2) the gasoline and diesel used for ground transportation and
3) the oil-derived synthetic natural gas distributed on Oahu.  

RNG in its raw form known as biogas can be used for electricity generation. RNG purified to pipeline quality natural gas (greater than 98 percent methane) can be used for ground transportation or injected directly into the existing natural gas pipeline distribution system on Oahu.  

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Benefits of Renewable Natural Gas

Capturing methane from wastewater treatment plants and landfills provides dual environmental benefits by preventing greenhouse gas emissions from entering the atmosphere and using it to displace other higher-emitting fossil-based fuels such as oil and diesel. Renewable natural gas emits approximately 30 percent less carbon dioxide than the oil and diesel now used to produce electricity and for ground transportation.