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Utility-scale solar for Utah

The recently completed 104-MW Red Hills solar project in Utah-the state's first utility-scale solar project-is bound to be the first of many, considering Utah is in the top six of U.S. states for solar power potential.

By Tony Kryzanowski

As one of the top six American states for solar power potential, it really comes as no surprise that solar power development in Utah is heating up.

Case in point: Scatec Solar's 104-megawatt (MW) project, the Utah Red Hills Renewable Park, came on line in December 2015 and is the first and largest utility-scale solar power installation in the state.

Energy industry intelligence gatherer Energy Acuity recently identified as much as two gigawatts (GWs) of solar power development occurring in Utah, with more being added on a regular basis. Part of what is spurring development is that Utah has required its utilities to provide 20 percent of their power from renewable sources by 2025.

As the first commissioned utility-scale solar power installation in Utah, Red Hills has played a vital role in bringing attention to the region as a prime solar power development area.

Discussions began on the Utah Red Hills Renewable Park project back in 2011. Developed by Norway-based Scatec Solar and located in southwestern Utah, it is currently Scatec Solar's only solar power facility in the United States. With the help of veteran engineering, procurement, and construction (EPC) contractor Swinerton Renewable Energy, construction began on the project in January 2015 and was completed within a year.

Swinerton also operates and manages the installation under contract, providing real-time data monitoring, plant control, and asset performance optimization, using its Solar Operations Live View (SOLV) platform. At the time of its commissioning, Red Hills was the largest solar project Swinerton had completed.

"Southern Utah is really a hot spot now," says Brian Irlbeck, project manager for Swinerton on Red Hills. "It got a bit of a later start than California, but it has a very good solar resource."

The $188 million Red Hills project is located on 632 acres of private land in a cooler, high desert environment at an elevation of 5700 feet. Irlbeck describes this as an excellent location for a solar farm. It is a single-axis solar array, consisting of 340,000 solar panels, capable of providing enough power annually for 18,500 homes. It will also reduce carbon dioxide emissions from fossil fuel power sources by 145,000 tons annually.

Swinerton Renewable Energy began its work as EPC on the Red Hills project in mid-2014, working with Scatec Solar in their discussions with local community leaders to better inform them about solar power in general and the construction and commissioning process in particular. The technology was something area residents knew little about.

 
  

Swinerton also designed the solar array for Scatec. Given Swinerton's experience as a solar industry EPC, Irlbeck says that they have good relationships with best-in-class suppliers that are able to provide proven solar power components within the required project specifications.

Albuquerque-based Array Technologies Inc. supplied its DuraTrack HZ single-axis tracking system for the project. JinkoSolar provided polycrystalline 72-cell 305/310 watt modules. Advanced Energy Industries provided its 1000NX inverters.

One specification designed into the project was a method to deal with the potential snow load on the site. The site is equipped with multiple snow sensors from 2KR Systems LLC of Barrington, New Hampshire. Once the supervisory control and data acquisition (SCADA) system detects a certain level of weight on the sensors, the single-axis tracking system is rotated to drop the snow from the modules. Deploying this technology allowed Swinerton to use a lighter racking system at a lower cost for their customer.

"This is the first system like this that we have installed, and I don't know of it being installed elsewhere," says Irlbeck. The snow sensors were procured from a company that typically uses the technology to monitor the potential for avalanches and ski conditions.

The single-axis array to track the sun's movement was chosen to maximize power production.

"You really do get a good bang for your buck from a single-axis tracking system compared to a fixed-tilt racking system," says Irlbeck. About 90 percent of projects within the company's market area are single-axis trackers. He estimates that this type of tracking system delivers up to 25 percent more production over the lifespan of a power purchase agreement (PPA), despite the extra costs up front. He added that there are situations where a fixed-tilt system is a better financial option, though.

 
The $188 million Red Hills project is located on 632 acres of private land in a cooler, high desert environment at an elevation of 5700 feet. The cool air in the high desert is a prime environment to maximize solar power production. 
  

Gilbert Development Group performed the site preparation on the Red Hills location. Alameda, California-based Blymyer Engineers worked with Swinerton on the project design and are the electrical and structural engineers for all of Swinerton's projects. EPC Services Company, a subsidiary of Electrical Consultants Inc. of Billings, Montana, built the substation. GSL Electric of Sandy, Utah, was the electrical contractor.

In addition to the cool air in the high desert being a prime environment to maximize solar power production, Irlbeck says the array also had a "phenomenal" tie-in footprint. It is located right next to Rocky Mountain Power's substation and transmission lines, meaning that a fence is the only thing separating the solar farm from the company purchasing the power it generates. Scatec Solar has signed a 20-year PPA with Rocky Mountain Power, which is a subsidiary of electricity supplier PacifiCorp. Google was also involved in the Red Hills development, providing tax equity on the project.

Tie-in of the project's 138-kV substation to the Rocky Mountain substation was a snap and done at a very low cost.

"It was probably a distance of less than 250 feet," says Irlbeck. "This is unheard of for convenience, with such close proximity to a substation. The site was probably one of the best locations we have ever built on, firstly, for the proximity to the interconnection, and secondly, because of the flatness of the site." He credits Scatec Solar for doing a first-class job of site selection for the solar array.

Local interest in solar power is being reflected by both public interest and in the numbers of new jobs the industry is creating locally. According to stats provided by the Solar Foundation, the state's solar development industry currently employs 2679 workers in 930 different endeavors. This year alone, job growth in this sector is expected to be 25 percent, versus a 1.9 percent state-wide growth in jobs.

 
 One specification designed into the project was a method to deal with the potential snow load on the site. The site is equipped with multiple snow sensors. Once the SCADA system detects a certain level of weight on the sensors, the single-axis tracking system is rotated to drop the snow from the modules.
  

Swinerton says that about 80 percent of its workforce on the Red Hills Solar Park was local, and Irlbeck says he suspects it was even higher—closer to 90 percent. There were 300 workers on site at construction peak.

Irlbeck adds that solar power development was something new in the state and—working in partnership with Scatec Solar—there was a fair amount of education required with local authorities to help them understand the intricacies of solar power development. He credits the effort to engage the community as a major reason the project permitting and development process proceeded smoothly. The best practices used by Swinerton on issues like recycling have helped to establish the template with local officials on how they want other projects to proceed.

"Scatec didn't come into town with an ego on how the project was going to be done," says Irlbeck. "They really talked to the folks at the county, had the public hearings, listened to everyone's concerns, addressed what they could, and the project was really well received."

Providing local jobs was high on the list of priorities for local leaders, and both Scatec Solar and Swinerton made this commitment. Irlbeck says spending the time to provide training to local trades on how to install the solar array under Swinerton's supervision meant that there was less travel required to bring in experienced workers, and they were preparing a local, trained workforce for other business opportunities that might become available in the area. This has happened. Irlbeck says that since completing the Red Hills project, Swinerton has continued to work on a number of utility-scale solar power development projects in Utah.

"Since the start of the Red Hills project, we've had eight more projects in southern Utah," he says. "One was a similar size to Red Hills, and the other seven were smaller." He adds that many of the suppliers to the Red Hills project have also realized considerable carry-over business on other projects in the state.

Swinerton also learned some important lessons as to the best timing for project construction in that region, as southern Utah's high desert does experience challenging winter conditions. While construction for the Red Hills project started in January, subsequent projects in the same area were scheduled to begin later in the year, in March.

But Utah weather can still be unpredictable. "There was snow on the ground in June a time or two while we were building the Red Hills project," says Irlbeck.

As a developer and operator of solar power installations, Scatec Solar has assets in such far flung locales as the Czech Republic, South Africa, and Rwanda. A publicly traded company headquartered in Oslo, it currently also has projects in development in Africa, the U.S., Asia, the Middle East, and Europe.

 


September/October 2016