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University of Arizona opts for wind-and solar power

The University of Arizona has partnered with Tucson Electric Power to provide its campus with enough power from new solar, storage and wind systems to serve all of its purchased power needs.

By Paul MacDonald

The University of Arizona (UArizona) takes pride in the recognition it has received for its work in climate research and environmental issues—with more than 65 research programs, labs, centers and institutes, UArizona faculty, staff and students work collaboratively to link cutting-edge knowledge with real-world issues.

Such programs make good sense, research-wise and on a practical basis, when you consider that hot, dry Arizona has a lot at stake in helping to deal with high temperatures, due to global warming.

The University of Arizona is also part of the University Climate Change Coalition, or UC3, which is committed to reducing climate-changing emissions and improving research on climate change policy across its 20 member universities in the United States, Canada and Mexico.

That proactive approach took a large step forward recently, with the university partnering with regional utility Tucson Electric Power (TEP) to provide its campus with enough clean, emission-free power from new solar, storage and wind systems to serve all of its purchased power needs.

"We made a commitment to become a more sustainable campus, and now we have a system in place that will make a significant impact," said University of Arizona President Robert C. Robbins, of the agreement with TEP.

"I believe it is up to higher education institutions to lead the way on clean energy solutions," Robbins added. "The University of Arizona is already a leader in environmental and sustainability research, and we found a partner in TEP that shares our commitment to make effectual change."

Under the agreement, TEP is dedicating portions of two new renewable energy projects to serving the energy needs of the university: a wind farm in New Mexico and a solar-plus-storage system southeast of Tucson.

The Wilmot Energy Center, on a site south of Tucson International Airport, includes a 100-megawatt solar array and a 30-MW energy storage system, each the largest of their kind on TEP's local energy grid. The system includes approximately 314,000 solar panels on 1,130 acres and is scheduled to come online in spring 2021. It was developed and is owned by NextEra Energy.

The Oso Grande Wind Project generates 247 MW for the university and other TEP customers. The project has 61 turbines installed on 24,000 acres southeast of Roswell, New Mexico, and it also came into service in December 2020. The project generates enough wind power to power nearly 100,000 homes.

Combined, the two new projects help TEP more than double its use of renewable energy. The Oso Grande project is TEP's largest single renewable energy resource—and adds considerably to the university's support of renewables.


"We had been researching a way to implement 100-percent green energy, and this deal got us there in one fell swoop," said UArizona Assistant Vice President of Facilities Management, Chris Kopach. "This project provides capacity for consistent and reliable power with capacity for decades of growth in Tucson and on campus."

Added to this, TEP is also working with climate experts at the Arizona Institutes for Resilience to develop measurable, science-based carbon-reduction targets to help guide its long-term resource development plans.

"This exciting project is consistent with the impactful cross-disciplinary research and teaching taking place at the University of Arizona," said UArizona Office of Sustainability Director, Trevor Ledbetter.

"Southern Arizona is one of the fastest warming areas in America, and anything we do to slow it down helps us at home. It is our responsibility to be a leader in this space and to do so alongside our community—and this project is a significant step in the right direction." UArizona's agreement with TEP will mitigate 30 percent of the university's carbon footprint.

UArizona and TEP have a long history of working together to expand educational opportunities and promote renewable energy. The 25 MW Solar Zone at Tech Parks Arizona—one of the largest multi-technology solar demonstration sites in the U.S.—is a joint venture by TEP, the university and solar developers.

"It incentivized a lot of different companies to put their technology there," says Ledbetter. "We have traditional PV there, concentrated solar and other types of solar.

"We have research going on at the Solar Zone that looks at the efficiencies of the different solar power systems, but also at how the technologies hold up over time, how their efficiencies drop over time, especially in the Arizona environment," he added.

The position of sustainability director at the university is a good fit for Ledbetter, who was heavily involved in campus sustainability in his undergrad work at UArizona.

Ledbetter noted there is a good deal of interaction and co-operation between the university and TEP in a number of other areas, including how weather, such as cloud cover, can impact the integration of solar on the grid. "That has enabled TEP to put more solar on to their grid because they're able to have more of an almost real-time capability of looking at the solar power that is coming on their grid, and can fire up reciprocating natural gas resources if they expect cloud cover to come over one of their large solar projects."

  Under the agreement with the University of Arizona, Tucson Electric Power is dedicating portions of two new renewable energy projects to serving the energy needs of the university: the 247 MW Oso Grande wind farm (above) in New Mexico and the Wilmot Energy Center, a solar-plus-storage system southeast of Tucson that includes a 100-megawatt solar array and a 30-MW energy storage system.

TEP also collaborates with scientists in the UArizona Institute for Energy Solutions to develop techniques to test batteries for storing energy.

Ledbetter said there were a few different factors that drove the recent solar/wind power agreement with TEP.

"It had come to the point where we could do a deal like this so that it would either be cost neutral or save the university money over time, so the economic argument was big. But it was certainly not the only one.

"We did this because it was the right thing to do—we needed to do it," he added. "The university has committed to carbon neutrality by 2040, and we're trying to move that up, to 2035."

As part of the overall agreement, there will be additional educational opportunities involving solar at the university, one involving agrivoltaics. "We have researchers who are interested in the energy, water and food nexus," Ledbetter says. The initial research that has already been done in this area shows that agri-voltaics can help support plants that don't traditionally produce well in a particular climate. Tomatoes, for example, either die or don't produce fruit during hot Arizona summers. In some cases, researchers have actually been able to triple crop production because they have been able to keep the plants cool under solar panels. And the transpiration of the plants can help keep the air cooler around the solar panels, reducing their temperature and increasing efficiency.

While UArizona was not involved in the equipment that was selected for the Wilmot solar and Oso Grande wind projects, the agreement with TEP resulted in the Oso Grande project being scaled up considerably.

The 247 MW Oso Grande Wind Project was among the first U.S. installations of the Siemens Gamesa SG 4.5 145 wind turbines. The 71-meter blade on the SG 4.5-145 turbine integrates aerodynamics and noise reduction features to guarantee a high production of energy, and reduced noise emission levels.  

The 247 MW Oso Grande Wind Project was among the first U.S. installations of the Siemens-Gamesa SG 4.5 145 wind turbines. The 71-meter blade on the SG 4.5-145 turbine integrates aerodynamics and noise reduction features—including Siemens Gamesa's DinoTails Next Generation technology—to guarantee a high production of energy and reduced noise emission levels.

And the wind power from the project's 61 turbines is a good fit for TEP's solar power production.

"This new wind farm will complement our many solar arrays, producing some of its strongest output during the morning and evening hours when we have little or no solar production," said Erik Bakken, Vice President of System Operations and Environmental, at TEP.

EDF Renewables developed the Osa Grande wind project for TEP through a build and transfer agreement for approximately $370 million. The project qualifies for federal tax credits that are expected to recoup more than two-thirds of its cost over its first 10 years of operation, savings that will be passed along to TEP's customers, including UArizona.

The power from the Oso Grande project in New Mexico is being delivered to Tucson through existing transmission lines that connect to TEP's transmission system in eastern Arizona.

The 100 MW solar array and accompanying 30 MW energy storage system located at the Wilmot Energy Center (WEC) is owned and operated by an affiliate of NextEra Energy Resources.

TEP's renewable energy production now exceeds 28 percent of its retail sales. That level is more than double the state requirement for 2021, while approaching the 30 percent goal TEP has planned to achieve by 2030.

Ledbetter had a few suggestions for other universities looking to do similar agreements with utility companies. "Start early," he says. "We were able to get things done with TEP very quickly, but if we started our conversations earlier with TEP, we could have wrapped things up earlier.

"I think there is a lot to be said for partnerships," said Ledbetter, noting all the collaborative work UArizona has done with TEP. "I'd add that like any good negotiation, you should not just focus on one piece—there were a variety of things that were packed into our agreement that made both sides happier." Such as solar demonstration projects on campus. "Little things on both sides can really help move forward an agreement like this."

The Oso Grande wind project is completed, and the Wilmot solar project is close to completion, but there will be more renewable power to come for the university. While it has an urban campus, which places constraints on ground-mounted solar, the university is actively looking at putting solar over parking areas, and on the roofs of some buildings.

"With the parking areas and the roofs on newer buildings, we have something like 4.8 MW of solar we could install," notes Ledbetter.

And on a broader scale, Ledbetter is generally optimistic about renewable energy, and more such agreements happening, with the Biden administration coming to power in Washington. "The new administration has a lot of ambitious climate goals, and I think that will make a big difference not only in how higher education, but also how private industry, approaches these agreements."