Tucson Electric Power performs system upgrades and maintenance all year long to make sure our energy grid is ready to run reliably through the hot temperatures, powerful thunderstorms and high energy demands of summer.
In 2025 alone, TEP invested more than $320 million in power lines, transformers, electric switches and other transmission and distribution equipment that we use to deliver service to customers every day.
“Our customers count on us to keep the lights on all year long, but it’s especially important during the hot summer months when we’re all running our air conditioners to stay cool,” said David Wagner, Director of Line Construction and Metering.
TEP has recently completed and continues to work on upgrades that strengthen our energy systems, reducing the likelihood of outages caused by storm damage or other factors that challenge our energy systems during summer months.
Making significant improvements in area substations
TEP made significant improvements to more than a dozen substations that transmit and help deliver service to customers throughout our service area. Some of these upgrades include:
- Investing more than $7 million to add a transformer and additional power lines into and out of the Pantano Substation in southeast Tucson.
- Investing more than $3 million in replacing 138 kilovolt (kV) and 46 kV breakers at the Northeast Substation.
- Investing more than $1 million to replace 138 kV breakers at the Drexel Substation in southern Tucson.
Improving neighborhood distribution lines
TEP invested more than $30 million last year in power lines and systems that connect to homes and businesses throughout our service area. These improvements included upgrading lines with thicker, stronger wires and voltage conversion projects that provide greater capacity to help meet customers’ growing energy needs.
New generation and support systems
Over the last year, TEP has added several new clean energy resources that will serve customers this summer.
A second, 200-MW phase of our Roadrunner Reserve battery energy storage system came online this month, just in time for summer. Both Babacomari Solar, a 160 MW solar project in Cochise County, and the Wilmot Energy Center expansion, a 100 MW solar and 100 MW battery energy storage system, also became operational this year and are now providing service to customers.
TEP also made significant investments to interconnect these systems to our local energy grid. For example, TEP invested more than $11 million to build the 138kV Whetstone switchyard, which allows clean energy produced at Babacomari Solar to be delivered to customers in Tucson. TEP also invested more than $7 million in substation and line upgrades to connect Roadrunner Reserve battery system to the grid.
Investments in our local energy grid support TEP’s efforts to maintain top-quartile reliability scores when compared to other energy providers across the nation. In 2025, a typical TEP customer was without service for just 42 minutes. That compares to a nationwide average above 100 minutes, with a number that falls well within the first quartile of results gathered by the Edison Electric Institute.
