1 MWp Power Plant in Arizona

Shelley Shelton; The Arizona Daily Star

A planned 1-megawatt solar plant in Avra Valley stands to help Tucson Water conserve energy, though it isn't likely to save the utility any money. Even so, the project — on which construction is scheduled to begin in October — is being hailed as a win-win for Tucson Water as well as for a nearby power utility that is trying to increase the amount of renewable energy it produces in order to meet a government mandate. The Arizona Corporation Commission has ordered that all regulated Arizona utilities must generate at least 15 percent of their power from renewable sources by 2025. That seems a long way off, but the commission has set smaller, incremental goals for the utilities to meet each year until then. Also, more power generated through renewable sources means less need for power utilities to build new plants to meet demand, industry insiders say. The Avra Valley solar plant is being built specifically to provide power to Tucson Water's Clearwater blended-water facility, which provides a little more than half of Tucson Water's total water supply and is projected to handle about 90 percent of Tucson Water's water within the next few years, said Fernando Molina, a Tucson Water spokesman. The new plant would offset about 5 percent of the electricity currently used at the Clearwater facility, which is about the amount of energy needed to produce 6.5 million gallons of water per year. The project came about at the urging of Tucson City Councilman Steve Leal, said Tom Arnold, a senior management analyst with Tucson Water. As it stands, the city owns the land where the solar station will be built, but the city will not own the station itself. That's being left to a company called SunPower, which will build the power plant and be responsible for its maintenance while selling the solar plant's electricity to Tucson Water. "From a strictly financial perspective it's basically a break-even project," Arnold said. But Tucson Water will get renewable energy credits that it plans to sell to Trico Electric Cooperative, which handles the electricity needs for the Clearwater facility. Meanwhile, Trico gets credit from the corporation commission toward its 2025 renewable energy goal, and Trico buys more time until needing to build more plants. The last plant that was built to serve the Trico area was built in 1961, though it's had some upgrades and add-ons since then, said Marsha Regrutto, manager of marketing and services for Trico. "If we could get enough of these systems online to meet growth, we could possibly avoid future generation costs," she said. "All of us (power companies) are getting close to maximizing our system capacities, so the alternative is to build more generation, which is extremely expensive." Leal said he's been trying for at least 10 years to get the city to look at building a solar plant. The beauty of the Clearwater location, he said, is the city didn't have to acquire the land because it already owned 21,000 acres there and wasn't using any of the surface because the land is for groundwater activity. Though the facility will initially be a 1-megawatt outfit, there's potential to expand it to 5 megawatts over time, he said. He wants to hasten the move from fossil fuel dependency to renewable energy, and big solar installations are the way to go, he said. "I'm glad we're putting solar on this building and solar on that building," Leal said. "But it's so incremental. We're never going to gain enough ground to solve the problem. We're all going to be dead."