How EDP Renewables is unlocking solar-plus-storage in rural America

Summer may already be long gone, but for residents of northwest Arizona, the memories of brutally hot summers remain. In Bullhead City, close to the Nevada border, high temperatures every day in August 2022 were above 100 degrees Fahrenheit, often nearing or surpassing 110 degrees. 

For Mohave Electric Cooperative, which is headquartered in Bullhead City and serves 37,000 primarily residential members, the high temperatures create huge spikes in power use every summer. 

“One of the unique challenges we have is that we have such a summer-heavy peak,” said Jonathan Martell, Mohave’s chief operating officer. ​“We can have a 100- or 125-megawatt swing between high and low on a day in the summertime.”

EDP Renewables, which operates more than 65 utility-scale renewable energy projects and more than 200 distributed generation projects throughout North America, is well versed in generating renewable energy in a variety of climates, enabling them to respond to the call of companies like Mohave Electric Cooperative that are looking to supply their customers with reliable, cost-effective clean energy solutions.

In the past, Mohave met its summer peak mostly by relying on the combined-cycle natural gas units it could access through the cooperative’s contracts with Arizona Electric Power Cooperative and Arizona G&T Cooperatives, a generation and transmission power supplier in the state. More recently, Mohave has diversified its supply mix with several solar power-purchase agreements. That resulted in Mohave owning a pair of solar projects that combined provide a combined 15 megawatts of power. It’s also partnering with AEPCO on a 20-megawatt solar project near Cochise County, Arizona.

“Years ago, we were heavy with coal and switched predominantly to natural gas,” Martell said. ​“It just made sense with some of the price breaks on solar to do an all-of-the-above strategy and not rely on one [source] where you are exposed when natural-gas prices spike or coal availability declines. With these projects, we have been able to gain even more fuel diversity.”

Another project the nonprofit cooperative is working on to ensure it can meet its sizable summer peak is a 17.6-megawatt solar power plant. The solar farm will be coupled with a 15-megawatt/60-megawatt-hour energy storage system built by EDPR’s distributed generation team, which will bolster reliability. That deployment is expected to be completed in early 2023.

This solar-plus-storage project will give Mohave more fuel diversification, which will limit its exposure to price hikes, especially when the cooperative must purchase wholesale power to meet peak demand.

EDPR’s first utility-scale solar project in Arizona, the 158-megawatt Sun Streams project, came online in Maricopa County in 2019. Since then, EDPR has developed distributed and utility-scale renewable energy projects across the region, including solar-plus-storage, for customers including large corporations, such as Walmart, and local utilities including Salt River Project.

Overcoming long-standing barriers to solar-plus-storage deployment

As the U.S. power system has integrated more and more variable renewable generation, solar-plus-storage has become an increasingly important solution for providing grid stability and reliability. A recent report by Lawrence Berkeley National Laboratory found that 285 gigawatts’ worth of solar-plus-storage projects were in interconnection queues at the end of 2021.

Although cooperatives provide power for approximately 13 percent of the population and have service territories that together cover more than half the landmass of the continental U.S., America’s 900-plus cooperative utilities account for only about 1 percent of total installed U.S. solar. To accelerate deployment, the U.S. Department of Energy’s National Renewable Energy Laboratory helped launch the Solar-Plus for Electric Cooperatives initiative in 2020 to provide education outreach and strategies to quicken the pace of project deployment for co-ops. 

In addition to developing resources to aid procurement of solar-plus-storage projects and highlighting relevant case studies, the initiative also produced a white paper that documents some of the policy challenges that can limit deployments. Key issues include co-ops’ inability to access tax credits and local permitting and zoning bottlenecks. 

For many cooperatives, the decision not to develop solar or solar-plus-storage projects has been purely financial. ​“What they want is cost-effective, price-certain power,” said Richard Dovere, chief investment officer at EDP Renewable North America’s distributed generation business, which as part of EDPR, was named a 2022 Top Workplace. ​“For a while, even on a subsidized basis, renewables didn’t provide that. You can’t blame cooperatives for not buying renewables, because they have to buy cost-effective power for their members.”

“We’re happy to be at the forefront of solar-plus-storage projects,” added Mohave CEO Tyler Carlson. ​“Having spoken to other cooperatives, they’re all weighing the additional cost and benefits of diversifying their portfolios.”

The power of partnership

The recently passed Inflation Reduction Act, which allows nonprofit electric cooperatives to receive direct payments for incentives earned under the federal Production Tax Credit and Investment Tax Credit, is likely to result in more solar-plus-storage projects being built.

The development of the Mohave solar-plus-storage project provides lessons about how cooperatives can deploy these hybrid systems — and highlights advantages for cooperatives that don’t want to develop these projects alone. For Mohave, experienced partners bolstered the efficient and successful development of its solar-plus-storage project. EDPR NA’s distributed generation business contracted with Prometheus Power Group to construct the solar portion of the project and partnered with Stem, leveraging its Athena software platform to optimize the dispatch of the four-hour battery storage system. 

“Stem’s Athena platform offers the visibility and controls needed to ensure Mohave is capturing the full benefits of its solar and the energy storage system, and Mohave can more strategically manage expectations of its dispatch strategy,” said Mary Adam, VP of sales at Stem.

Partners with expertise in the finance, design, construction and operation of solar-plus-storage projects can both help cooperatives deploy solar-plus-storage more quickly and position them to fully reap the benefits of pairing the technologies together. 

Although EDPR is a leader in international renewable development spanning solar, wind, energy storage, offshore wind and green hydrogen, the company can also scale down its approach to a hyper-local focus when projects demand it. According to Dovere, EDPR has managed hundreds of projects that have helped it build up the kind of expertise cooperatives need to call on when considering similar projects with help from funding from the Inflation Reduction Act. 

“With distributed generation, it’s a local business driven by local relationships and expertise,” said Dovere. ​“The best partnerships are the one that takes advantage of the kind of local expertise that Prometheus provided, but also the development capabilities and technical capabilities EDP Renewables brings. The details matter — and you need partnerships to get them right.”

EDPR’s brand tagline, ​“Changing tomorrow now,” reaffirms the company’s commitment to its partners, employees, sustainability, and innovation — leading the energy transition and paving the way to a net-zero-carbon future. EDPR NA was recently recognized by the Houston Chronicle as a Top Workplaces Award recipient in the Houston Metro Area and was also honored with the 2022 Women-Led and Diversity, Equity & Inclusion Practices Awards.