Dive Brief:

• Tucson Electric Power last week unveiled plans for a power mix that relies more on renewable power and less coal, ultimately aiming to reach 30% green energy in just over a decade.
• TEP's Integrated Resource Plan (IRP) intends to add about 800 MW of renewable power by 2030, and has signed an agreement with NextEra Energy Resources to buy power from a new 100 MW wind facility. The utility is also considering an agreement that could bring another 100 MW online as well.
• The plan also calls for 192 MW of natural gas generation between 2020 and 2022, along with "a number of energy storage projects" sized at about 50 MW, 50 MWh. By 2030, the plan expects 150 MW of new gas generation, along with a 100 MW, 100 MWh storage facility.
• The IRP also calls for shutting down a 170 MW coal-fired unit at the San Juan Generating Station in New Mexico and ending a supply agreement in June 2022 that will take another 170 MW offline at the facility.

Dive Insight:

TEP continues to shift away from coal-fired generation, last week unveiling the better part of a gigawatt of clean energy, just two months after announcing it would go forward with three storage projects designed to improve the resiliency of its grid.

The utility filed its 15-year plan with the Arizona Corporation Commission.

“We’re evolving from a traditional utility to a more technology- and consumer-focused provider of energy products and services while maintaining reliability, convenience and affordability for our customers,” TEP President and CEO David Hutchens said in a statement.

In the next five years, the utility will stop utilizing coal-fired power from the San Juan station. And TEP plans to diversify its generation portfolio by expanding solar and wind generation, aiming for 30% renewable energy by 2030, about twice the level as is required by 2025 under Arizona’s Renewable Energy Standard.

The utility also is preparing for the retirement of the coal-fired Navajo Generating Station, though participants have agreed to run the plant until December 2019 if a land lease extension can be reached. TEP owns 7.5% of the generation, about 168 MW.

While TEP is adding carbon-free energy, the utility is also looking to natural gas. The company said it will add more than 190 MW of gas by 2022 "to provide replacement capacity for the retirement of older, less efficient natural gas steam units at Sundt (Units 1 and 2)." 

Those assets are expected to "assist in mitigating power fluctuations associated with renewable resources," along with a number of energy storage additions. 

"In addition to the 120 MW of battery [energy storage systems] installed by 2021, the 2017 IRP Reference Case Plan assumes the addition of energy storage in 2031," the IRP reports. "This system would be 100 MW x 100 MWh and could provide a combination of ancillary, peak capacity and load‐leveling services."

The storage facilities would build on recent investments at TEP, including a deal with NextEra to build a 10 MW, 5 MWh lithium nickel-manganese-cobalt energy storage system at a TEP substation to help maintain reliability during peak demand periods.