Renewable energy is typically associated with solar, wind and hydropower, but it can also come from farms, food waste and landfills in the form of natural gas. This type of natural gas is called Renewable Natural Gas (RNG), which is any pipeline-compatible, gaseous fuel derived from biogenic or other renewable sources with lower lifecycle CO2e, or carbon dioxide equivalent, emissions than geological natural gas. 

With advancements in alternative gas technologies, RNG produced today comes from capturing emissions from existing waste streams found in landfills, wastewater treatment plants and animal manure. This renewable energy, in the form of RNG, can be processed and injected into natural gas pipelines to be used as a clean, reliable energy source for homes, businesses and electric generation. It can also be used as transportation fuel, providing a cleaner option than diesel.

How does the RNG life cycle work?

  1. Capturing Energy – Beginning the RNG journey at a landfill or a dairy, swine or poultry waste farm, emissions are captured from lagoons or digesters.

  2. Cleaning and Processing – The captured emissions are processed and cleaned to pipeline quality standards so that they can be injected into Piedmont’s system as RNG.

  3. Customer Use – The RNG is injected into Piedmont’s natural gas infrastructure to serve homes and businesses in a sustainable environment.
Any RNG supplier who works with Piedmont Natural Gas to inject alternative gas onto Piedmont’s infrastructure must meet strict natural gas quality standards. Piedmont continuously monitors natural gas quality with advanced instrumentation and can automatically stop the receipt of RNG if standards are not met.  

These quality standards ensure Piedmont’s ability to continue providing safe, reliable and affordable natural gas service to our customers.

renewable natural gas diagram
Source: American Gas Association