Arizona Public Service seeks to renovate Tempe plant

The Tempe skyline will be getting a bit of a facelift, all while improving the city's economy and environmental sustainability as well.

Arizona Public Service has announced it will be renovating its Ocotillo Power Plant, located on University Drive in Tempe, near the ASU Karsten golf course.

APS is the largest energy provider in Arizona as well as the state's largest tax payer. It provides power to Flagstaff, Prescott and Yuma, as well of around two-thirds of the Valley, which it shares with the Salt River Project.



The plan is to remove the larger two of four generating units at Ocotillo, and replace them with five smaller, more efficient, more powerful units. Three large storage tanks that have fallen into disuse since the plant's conversion from oil to natural gas in the 1980s.

APS spokesman Steven Gotfried said the new units are a huge improvement over the others.

The new unit are cheaper, more efficient in terms of fuel and water consumption, and they create a better visual,” he said.

James Anderson, who teaches in the ASU School for Engineering of Matter, Transport and Energy, said the environmental changes coming with the renovation are good ones.

In the long term, we need to get away from fossil fuels, including natural gas because of the climate forcing effects of carbon dioxide," he said. "In the shorter term, natural gas is a cleaner fuel that results in lower emission of carbon dioxide per unit energy compared to coal and fuel oil. But as long as there isn’t enough solar, wind and other alternative energy sources then this type of natural gas power plant needs to exist and be renovated from time to time."

The initial investment in the new units will serve to help growth in the Valley, Gotfried said. The plant's generating capacity will go from 320 megawatts to 620, allowing the plant to power 165,000 homes compared to the current 83,000.

The five new units combined will use 15 percent less natural gas and 85 percent less water than the two old ones, will be half of the original 178-foot height and will also be quieter than the old plants, Gotfried says.

The renovation will also increase the amount of property tax they pay on the site, increasing it from $600,000 to $8 million by the fifth year of operation, Gotfried said.

Sustainability graduate student Tony Perez said he thinks that the plan is a good investment for the company.

A lot of older systems need upgrades to be efficient, and it's a lot cheaper to retrofit the old plants than to invest the money elsewhere, like in renewables,” he said.

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