The Arizona Corporation Commission has approved two large energy storage projects by Tucson Electric Power (TEP).
TEP has entered into long-term agreements with E.On Climate & Renewables and NextEra Energy Resources for construction of two systems under 10-year contracts. The utility said that the project partners delivered bids which allow TEP to build both systems for less than the original estimated cost to build one 10 MW energy storage solution.
“We hope that innovative systems like these will help us achieve our long-term renewable energy goals without compromising the reliability or affordability of our service,” said David G. Hutchens, TEP’s President and CEO, in a statement. TEP is working to deliver at least 30 percent of its power from renewable resources by 2030, doubling the state’s 2025 goal.
In June 2015, TEP issued a request for proposals to lease a large, 10 MW energy storage system. With bids submitted by more than 20 qualified vendors, TEP was able to select two competitively priced proposals.
“Because our project partners were motivated to demonstrate the capabilities of their respective technologies, they submitted favorable bids that will allow us to build both projects for less than our original estimated cost to build a single 10 MW system,” said Carmine Tilghman, a TEP Senior Director who oversees the company’s renewable energy programs. “These systems will help us build a more resilient grid at a reduced cost to consumers.”
The other 10 MW storage battery is lithium titanate oxide and will accompany a 2 MW solar power array located at the University of Arizona Science and Technology Park southeast of Tucson. E.On is building that facility and should complete it by the first quarter of 2017.
TEP will use the systems to boost power output levels and maintain voltage frequency on the regional electric grid. These large-scale battery options also can help prevent outages during period of high demand, providing about 5 MW of power for up to an hour.
The storage options are cheaper for the utility than building new generating resources, TEP reported. It also allows TEP to defer costly investments in other system infrastructure.
TEP said it will continue investing in large solar arrays and other community scale renewable resources that add cost-effective capacity to its renewable energy portfolio. TEP anticipates an additional 800 MW of new renewable capacity by the end of 2030, boosting its total renewable energy portfolio to about 1,200 MW.
TEP delivers electric service to about 417,000 customers in Southern Arizona. TEP and its parent company, UNS Energy, are subsidiaries of Fortis Inc., which owns utilities that serve more than 3 million customers across Canada and in the United States and the Caribbean.