The most recent addition to this effort is through the Butterfield Dairy in Buckeye, which has been outfitted with new technology to help turn cow manure into renewable natural gas.
“We safely deliver reliable, sustainable and affordable energy to over 2 million customers in the service territories,” Southwest Gas Director of Emerging Technology and Innovation Joe Varela said. “We’re committed to creating a reliable and sustainable energy future for everyone.”
The process of creating the renewable natural gas (RNG) is something Southwest Gas and other companies across the West Coast and Southwest United States have been thoroughly involved in.
Starting with the dairies, these are locations with cows that have the sole purpose of creating milk. After a dairy has been selected for the process of becoming a biogas location, it is then renovated with lanes that flush the manure to a central processing facility.
This filtration system sends the manure into a designated digester, where methane is captured and the solids are broken down by microorganisms — thus creating the biogas.
After the biogas has been made, it is pulled out of the digester by low pressure into a chemical cleanup station, where the product is stripped of chemicals, like hydrogen sulfide, and moisture. From there it is then pushed out by Southwest Gas, providing clean and renewable energy to the community.
“So once it’s captured, then the benefit to the community is that those fugitive methane emissions from the decomposition or the biogas are no longer going into the local community,” Varela said. “And that’s where Southwest Gas — being a forward-thinking utility — wanted to be involved, and help these RNG developers take that raw biogas and bring it to the marketplace.”
According to Varela, the benefit of bringing RNG to the marketplace — along with protecting the atmosphere — is it serves as a revenue stream for the dairy farmer or the RNG developer.
“(The Arizona Corporation Commission) saw the value in this type of service being offered to customers, and they approved our tariff in Arizona to allow us to engage in these activities,” he said. “And what that allows us to do now is if you look at that dairy farmer, for example, we could invest in infrastructure — and then in agreement with whoever the biogas producer may be — to build, own and operate the gathering equipment, and then the claiming and upgrading equipment, and then the interconnection into our existing facilities.”
The use of RNG is widely practical in society. Varela claims the gas can be used for at-home heating, generating electricity and powering natural gas vehicles. This process also being in Arizona will help offset the need to purchase RNG from other states.
“We’re very excited to do our own cleaning and upgrading project, and we hope to do one in the near future,” Varela said. “But we are definitely involved in doing these interconnections to help these RNG developers bring it to the marketplace.
“It’s pretty exciting because you get to displace gas that now you’re not buying from West Texas anymore; you’re not depending on that. It’s local, and it’s helping out the community, which is a great win-win.”
With the door opened on creating new forms of energy for the community, Southwest Gas will use the momentum from Butterfield to create more-advanced RNG, in the form of hydrogen. The goal of using hydrogen is to help create an even cleaner product by managing the amount of carbon released into the atmosphere and helping customers achieve their sustainability goals.
“We’re very excited,” Varela said. “It’s just a wonderful story. … We are taking a product that was basically sitting in a field as a heap and turning it into a marriage resource that can be utilized.”
