Tucson-area electric co-op honing in on renewable energy with new solar farm

Customers of Marana-based Trico Electric Cooperative will soon be getting more clean power from a solar farm with battery storage the rural co-op is constructing west of North Oracle Road near Catalina.

Expected to go into operation in June, the Chirreon Solar and Battery Storage Facility will have a generating capacity of 10 megawatts of photovoltaic power and 15MW of battery storage to supply power when the sun goes down.

Once operational, the Chirreon facility will produce more than 30,000 megawatt-hours of energy each year or enough to power about 3,000 average residential homes, said Trico, a nonprofit co-op with about 50,000 members in rural parts of Pima, Pinal and Santa Cruz counties.

Trico is partnering on the project with Virginia-based developer Torch Clean Energy and SOLV Energy, a California-based engineering and construction firm; with financing through CoBank, part of the U.S. Farm Credit System.

Trico and its partners are not disclosing the cost of the Chirreon project. Nationally, the installed cost of 100MW utility-scale photovoltaic systems without storage averaged about $1 per watt, or about $1 million per megawatt, according to the National Renewable Energy Laboratory.

Chirreon, being built on about 90 acres of state-owned land in the Trico service area on East Edwin Road, west of North Oracle Road, is Trico’s second major solar farm project and the first with battery storage.

The co-op built a 10MW photovoltaic system in Marana that went online in 2018 and is partnered with other co-ops on a 20MW solar farm adjacent to the coal-fired Apache Generating Station in Benson.

Trico CEO and General Manager Brian Heithoff said the co-op uses about 25% renewable energy now and has big plans to add more renewables, as well as battery storage, in the near future.

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The battery system at Chirreon is one of the first among Arizona electric cooperatives and Trico has more in the planning stages, said Heithoff, who was named head of Trico a year ago after serving a decade as CEO of an electric co-op in Wyoming.

Besides helping meet energy demand in the late afternoon and evening when solar production drops off, Chirreon’s storage system will help Trico delay the cost of transmission and distribution upgrades and manage the local load more efficiently, he said.

Heithoff said the co-op recently put out a request for proposals for up to 200MW of renewable energy, and plans to widen member participation in renewables by offering them shares in energy produced by community solar farms or renewable-energy credits, for example.

“We are we are about 25% renewable today in our portfolio and we’re not only increasing that through projects like this, and future projects, but also interested in giving our members options to potentially go to 100% renewable if they so choose,” Heithoff said, citing the co-op’s member-based mission.

In 2011, Trico built a small, 227-kilowatt system known as the Sunwatts Sunfarm near its Marana headquarters, with funding from members’ purchase of the system’s output and a federal grant.

The co-op is now considering designs for new subscription-based community renewable energy programs, Heithoff said.

“We haven’t sorted through all of the options, but there are ways through renewable energy credits to allow members to basically displace all the fossil fuel generation on their own monthly bill,” he said.