TEP has submitted an agreement to purchase to the Arizona Corporation Commission (ACC) for review. The total renewable energy capacity will be 160 MW.
Solar power would constitute 107 MW of the total in 7 photovoltaic (PV) arrays in the Tucson area, as well as three concentrating solar power (CSP) systems.
Three of the solar PV arrays would use stationary panels with capacity of 35 MW, 25 MW and 5 MW, while four other solar PV arrays would use single-axis suntrackers with capacity of in 12 MW, 4 MW and two at 5 MW apiece.
One of the CSP systems would be 12 MW in capacity, while the other two would be rated at 2 MW each.
A 50 MW wind farm would be developed near TEP's existing natural gas Luna Energy Generating Station in Deming, New Mexico, and the electricity would be delivered to Tucson through an existing transmission line already used by TEP.
TEP also has agreed to purchase renewable energy from a new biogas generator that would be built at a landfill site in Pima County. It would produce 2.2 MW from methane gas.
Renewable capacity to add to TEP portfolio
Endorsement from ACC would allow renewable energy system developers to finalize financing, secure land rights and clear other regulations, in hopes of completing projects to begin providing power next year or in 2012.
Although some of the planned projects may not be built, the new capacity will represent a significant addition to TEP's growing renewable energy resources.
With funding provided by customers, TEP has developed 10 MW of company-owned renewable energy generating capacity, plus 6 MW of customer-sited systems subsidized by the company's popular SunShare rebates.
“These agreements are the next step in our development of local utility-scale renewable power projects that will help us achieve our renewable energy goals,” explains Paul Bonavia of TEP. “We're looking forward to including these resources in TEP's growing green power portfolio.”
New renewable energy to complement solar systems
The proposed renewable power systems would complement two new solar power systems already planned to be built in the Tucson area by January 2012. Fotowatio Renewable Ventures is building a 25 MW single-axis PV array near Marana, while Bell Independent Power is building a 5 MW CSP plant at the University of Arizona.
ACC has expressed support for TEP's agreements to purchase the output of both systems, which will provide power for 6000 homes.
Before those systems are commissioned, TEP will add 1.8 MW of capacity this year to its 4.6 MW Springerville solar system, which is one of the largest grid-tied solar PV arrays in the United States.
TEP will build a 1.6 MW single-axis tracking array in Tucson this year that could support the utility’s proposed Bright Tucson Community Solar program. That program is awaiting regulatory review, and would allow customers to buy 150 kWh blocks of solar energy produced by solar arrays in the Tucson area.
Arizona wants 15% renewable energy by 2025
The output of the existing and proposed systems will help TEP to meet the renewable energy goals established by ACC through the state's Renewable Energy Standard. The rules require TEP and other Arizona utilities to increase their use of renewable power each year until it represents 15% of their retail energy in 2025.
Tucson Electric Power provides power to 400,000 customers in southern Arizona. It is a subsidiary of UniSource Energy.