Nevada-based Gradient Resources kicked off operations in January of the first phase of its Patua Geothermal Plant – an accomplishment that took years in the making. Back in March 2011, the vertically integrated explorer and developer of geothermal energy projects announced that it had signed an engineering, procurement and construction contract with design/build firm Benham Constructors LLC for a new 120-megawatt modular binary cycle power plant at its Patua project in northern Nevada. 

The site is located approximately 38 miles east of Reno and about 10 miles east of the town of Fernley. Five currently operating geothermal power plants are located within 30 miles of the Patua project. The Patua project is characterized by manifestations indicative of high temperatures near the surface, including 13 hot springs ranging in temperature from 82F to 204F. 

The initial phase is being constructed to produce 60 megawatts and is expected to power 15,000 homes annually. The plant’s output will be supplied to the Sacramento (California) Municipality Utility District under a 21-year power purchase agreement that was signed in April 2010. Although the power will travel outside of the state, the company maintains that this project benefits Nevada, as well. 

Gradient Resources says the facility represents a significant investment in the state of Nevada and will provide long-term employment for the approximately 20 full-time plant staff and employees of the local businesses who will provide support to the operations.

“When this project is complete, we will have erected approximately $300 million in steel, concrete and equipment, including the cost of labor,” Gradient Resources CEO Craig Mataczynski says. “Of this $300 million, approximately $50 to $60 million will be filtered back into the local economy. This is, in my view, a big deal and will have a positive impact on the City of Fernley, Churchill County and surrounding areas.”

Putting Things in Place

One company Gradient Resources called on to make this project possible is Performance Mechanical Contractors (PMC). Over the last decade, the California-based PMC has become an industry leader for installation, construction and maintenance of geothermal plants. PMC has extensive experience with all types of geothermal plants including dry steam, binary, single, dual and triple flash.

PMC was the general contractor for the installation of the cross-country brine piping for the Patua plant’s gathering and injection systems. Its construction tasks included all right-of-way and access road grading,  installation of more than 2,600 drilled concrete and steel pipe supports, more than 45,000 linear feet of piping and approximately 38,200 diameter inches of welding. PMC’s work also included 10 road crossings, installation of pipeline through an environmentally sensitive drainage ditch and boring underneath the existing Union Pacific Railroad. 

“We had to excavate around 30 feet below grade  to set up a boring operations to get underneath the railroad line,” Project Engineer Shane Dooley says. “It covered 680 linear feet and we installed four 42-inch road crossing casings. It took a lot of coordination between us and the railroad because there are strict standards when working in the railroad’s right-of-way.”

Another major challenge on the project was a very unexpected one, according to Dooley. “We also encountered high levels of groundwater and we didn’t know the groundwater was so high until we started digging,” he says. 

PMC’s portion of the work lasted from mid-April to September of last year. Gradient Resources plans to start drilling on the phase 2 of the Patua project by second quarter of 2014. The company plans to have up to 11 additional well pads that are already planned into the phase 2 use permit application. There are also nine miles of piping planned, which will transport geothermal brine to the phase 1 geothermal plant.