Campus solar power

Tennessee's Vanderbilt University recently "flipped the switch" on the 35 MW Vanderbilt I Solar Farm, a big step in the university's goal to power its campus entirely through renewable energy.

By Robin Brunet

The 35-megawatt (MW) Vanderbilt I Solar Farm in Bedford County, Tennessee, may not be huge compared to the mega solar projects being built in the western U.S., but it’s a flagship project for the region nonetheless—and arguably something that may have historical significance down the road.

That’s because prior to the program that would ultimately facilitate the project, officials within the Tennessee Valley Authority (TVA) believed the region had sufficient conventional energy to sustain customers over the long haul.

“The development of renewables wasn’t a strategic priority for them back then,” says Matt Beasley, Chief Commercial Officer at Silicon Ranch Corp., the Nashville-based full-service solar and carbon solutions company responsible for Vanderbilt I’s creation.

In fact, just a few years ago, Tennessee had the dubious distinction of ranking last of all 50 states in access to renewables (only .4 percent of the state’s energy mix is solar, despite an abundance of land and sunshine).

Beasley and colleagues view Vanderbilt I as a prime example of how a medium-sized project can trigger a meaningful push towards more renewables developments that will cumulatively make a positive economic as well as environmental impact in Tennessee.

Vanderbilt I was first announced in 2020 as part of a collaboration between Vanderbilt University, the TVA and Nashville Electric Service (NES). It was designed to mitigate approximately 70 percent of the university’s annual indirect greenhouse gas emissions, or the equivalent of enough power to help serve more than 6,000 homes for one year.

Ground broke on the project in January 2022 some 60 miles south of the Vanderbilt campus, with Silicon Ranch funding the project (to the tune of more than $50 million) and overseeing construction, in addition to owning, operating and maintaining the farm.

 “We initially acquired 350 acres of land and tried to keep civil work to a minimum because, as with so many of our projects, we plan to manage the existing healthy vegetation with rotational sheep grazing,” Beasley says.

He adds, “From pile driving to installation and interconnection, we oversaw all of the work ourselves, since we’ve built a fully integrated team to support our business model of long-term ownership of our entire portfolio.”

 Technical considerations are one thing, but Vanderbilt I is the outcome of a fundamental paradigm shift within the TVA, to recognizing the economic development benefits of renewable energy procurement.

 “It’s a remarkable transformation,” Beasley says. “I was first elected president of our industry trade association (the Tennessee Solar Industries Association, or TenneSEIA) in 2015 and immediately began lobbying TVA for more renewables—but back then it was a tough sell.”

 At the same time Beasley was trying to make headway, Vanderbilt was approaching renewables firms (including Silicon Ranch) with regards to the university’s FutureVU sustainability and land development planning program, which was intended to make the institution carbon neutral and power the entire campus with renewable energy by 2050. Vanderbilt’s leadership wanted to know: could a commitment to a 100 percent renewables target actually be met?

 Beasley recalls, “It was a key question for them to ask at that time, because many companies and institutions were making that commitment, but with no clear means to achieve it. In order for the university to realize its goals, the Nashville
Electric Service—which serves Vanderbilt—would also have to advocate on behalf of their customers with the TVA.”

 Fortunately, into this mix came Google and Meta (formerly the Facebook company), both of which expressed interest in building data centers in the Valley—but demanded that they be 100 percent powered by renewable energy.

“We were already serving Meta in Georgia and had worked with other data centers, and we knew the economic advantages companies of this magnitude could bring to our home region,” Beasley says. “So this emerging economic development opportunity, combined with the ambitions of a venerable local institution such as Vanderbilt, compelled us to lobby the TVA along the lines of, ‘Look, your phone may not be ringing off the hook but ours is. So let’s talk about how we can collaborate to benefit the Valley.’”

TVA listened, and in 2018 it created the Green Invest program, which matches demand for green power from commercial, industrial and institutional customers with new utility-scale solar projects located in the Valley. Vanderbilt I Solar Farm became the first project developed under the program, in a collaboration with NES and Silicon Ranch, and was announced by the TVA in January 2020.

A location for the solar farm was secured, and Nick de Vries, chief technology officer at Silicon Ranch, describes the site conditions. “There was a natural subdivision in the form of a creek and some rocky areas with tree stands,” he says. A road was subsequently built on the site, as well as a bridge spanning the creek.

De Vries adds, “The biggest challenge in site prep was having to drill and backfill in some areas for the piles, and this changed our rate of build. But we had worked on far more difficult sites in the past, so we were still able to build on time.”

Vanderbilt I required 101,970 First Solar Series 6 Plus modules, which Silicon Ranch augmented with
Array Technologies Inc. (ATI) DuraTrack HZ single-axis tracking systems. ATI is known for engineering its systems to withstand extreme conditions while boasting some of the highest energy returns, peak performance and reliable life span. “We use single axis units on most of our installations these days,” Beasley says. “Single axis is more economical than fixed tilt and you capture more of the early morning and late afternoon sun.”

De Vries says of First Solar, “We have a long standing supply agreement with them, and their modules have a high energy yield.” The Series 6 Plus modules are said to generate up to eight percent more energy per watt (430-460 watts) than conventional crystalline silicon solar modules, and unlike crystalline silicon modules, First Solar’s thin film technology does not experience the losses associated with LID and LeTID—all of which contributes to a fast energy payback time.

Installation of Vanderbilt I took place in the spring of 2022 with 250 people working on site at peak, and de Vries notes that because this was a medium-sized project, there was no need to build a substation. “This was a 25kV interconnect project as opposed to 115kV, which is used to transmit much further distances,” he explains.

Vanderbilt I’s development was accompanied by a host of other business investments. In 2022, Silicon
Ranch donated 30 acres of its project site to the city of Shelbyville and Bedford County to support the
recruitment of Duksan Electera America, an electrolyte manufacturer for the electric vehicle industry that will invest $95 million to locate its first manufacturing plant in North America.

Vanderbilt students, faculty and staff at the Vanderbilt I Solar Farm (above). There is more solar power to come for the university. Silicon Ranch Corp., which owns Vanderbilt 1, has plans to build another solar farm over the next few years in Lynchburg, Tennessee. It will offset the remaining 30 percent of Vanderbilt’s indirect greenhouse gas emissions.

By that point Google had already broken ground on a $600 million data center in Montgomery County, and TVA had announced a Green Invest partnership with Meta for multiple
solar projects in the Valley.

Since 2018, TVA’s Green Invest program has attracted nearly $2.7 billion in solar investment and procured over 2,100 MW of solar power on behalf of its customers.

When Vanderbilt I became operational in April of this year, Eric Kopstain, the university’s Vice Chancellor for Administration, told media, “Innovation is a core element of the DNA of Vanderbilt University, and this is a wonderful example of innovation and partnership.”

However, Silicon Ranch’s work with Vanderbilt is not done: another solar farm is scheduled to be built over the next few years in Lynchburg. It will offset the remaining 30 percent of Vanderbilt’s indirect greenhouse gas emissions and produce 200 megawatts of energy, half of which will be received by Metro Nashville as a part of the city’s goal of only using renewable energy sources by 2041. Additional output from the solar facility will serve Jack Daniel’s, whose world-famous distillery is located just a few miles from the project site.

In addition, Silicon Ranch is providing a unique service to the university via Clearloop, which it acquired in 2021. Clearloop’s mission is to decarbonize the grid in communities that can benefit the most by using tangible, traceable carbon offsets. Brands such as Intuit, Rivian, and Vista Equity Partners have partnered with the company to ensure that carbon offsets are not just nebulous credits on dated registries but actual, tangible investments in local communities.

Clearloop Co-Founder and CEO Laura Zapata says, “Vanderbilt wants to tackle its carbon footprint beyond its energy usage, so we’ll be tackling the remainder of its carbon footprint—everything from the daily activities of operating a major institution—and match it to brand new solar projects that will avoid that same amount of carbon from coming out of the energy grid.”

Meanwhile, in addition to helping the university achieve its green goals, the collaboration between Clearloop and Vanderbilt is kicking off a more formal program for faculty and students for educational and research opportunities. “We regard Vanderbilt I as a genuine landmark project,” Beasley says. “As
a side note, over two dozen Vanderbilt alumni work at Silicon Ranch, so we’re extremely proud to have been able to make this solar farm a success.”

Q3 2023