15 May 2021

TEP's Largest Solar Plus Storage System Now in Service

15 May 2021  by   

Tucson Electric Power can deliver more solar energy than ever before — including when the sun isn't shining — with Tucson's newest and largest solar power system now online.

The new Wilmot Energy Center (WEC), located on 1130 acres southeast of Tucson International Airport, includes a 100-MW solar array and 30-MW battery energy storage system — each the largest of its kind on TEP's local energy grid. TEP will purchase power from the WEC under a long-term agreement with an affiliate of NextEra Energy Resources, its owner and operator.

The batteries will be charged by 314,000 solar panels that can track the movement of the sun for increased production. On most days, TEP will charge the battery in the morning and early afternoon when solar resources are most productive, then deliver stored energy during peak usage periods. The WEC will produce enough energy over the course of a year to serve the annual electric needs of about 26,000 homes.

"Storage makes solar power even more valuable by helping us provide clean, renewable energy when customers need it most," said Susan Gray, TEP president and CEO.

Battery storage is critical to a clean energy future because it helps utilities provide reliable service with growing levels of wind and solar resources. Storage can help smooth out imbalances when clouds block the sun or wind patterns shift and can store clean energy for periods when customers need it most.

This month, TEP will also start delivering power from its new 250-MW Oso Grande Wind project in New Mexico. With the addition of the two systems, TEP has the ability to produce nearly 26% of its power from renewable resources. The systems are a big part of TEP's plan to provide more than 70% of its power from renewable resources and reduce carbon emissions 80% by 2035.

"These systems more than double our large-scale renewable energy resources and represent a big step toward the cleaner, greener grid we're building for our customers," Gray said. "TEP is taking action on behalf of our community to protect our climate."

In addition to providing cleaner energy for every customer, the new systems allow TEP to provide 100% clean energy to the University of Arizona's main campus through an innovative long-term partnership. The agreement is the largest bilateral renewable energy agreement between a university and an electric utility in North America and enables the school to offset all of the greenhouse gas emissions associated with its purchased electricity.

"I am incredibly proud and grateful the University of Arizona is partnering with TEP on this important initiative," said University of Arizona President Robert C. Robbins. "Building a sustainable future is one of the university's strategic priorities, and this project will have a huge impact in reducing our carbon emissions. I am very excited for what we will be able to accomplish together."

The Oso Grande Wind farm will generate enough power each year to serve the annual electric needs of nearly 100,000 homes. Located on 24,000 acres of desert in southeastern New Mexico, the Oso Grande site was chosen for its proximity to transmission lines and its strong wind, particularly during the morning, evening, and overnight hours, when solar arrays produce little or no power.

With both the WEC and Oso Grande online, TEP will have 628 MW of large community-scale wind and solar resources, with more arriving soon. The 99-MW Borderlands Wind Project, being built about 100 miles south of Gallup, New Mexico, is expected to be in service by the end of 2021. TEP customers also have installed more than 29,000 rooftop solar systems with a combined capacity of about 300 MW.

These renewable resources support the ambitious clean energy goals outlined in TEP's Integrated Resource Plan, which describes how TEP will serve customer energy needs over the next 15 years. By replacing coal-fired power plants with less carbon-intensive resources, TEP's plan will avoid the production of more than 50 million tons of carbon dioxide over 15 years — equivalent to taking three-quarters of a million cars off the road.

Customers can check TEP’s renewable energy output anytime by visiting the Clean Energy Tracker here. Updated every three minutes, the gauges and graphs provide a real-time look at how TEP is satisfying customer energy needs with wind and solar power.

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