Two of Arizona's largest electric utilities say they are on track to meet the state's requirement that they generate 15 percent of their power from solar and other renewable sources by 2025.

Arizona Public Service, based in Phoenix and serving most of the state, will be generating 10 percent of its power from renewables, mostly solar, by 2015 and will meet the state's standard, said Ted Geisler, AZ Sun program manager for APS.

"We're right now on track to meet the Arizona renewable energy standard of generating 15 percent of our total resource needs by 2025," Geisler said. "In addition, APS has committed to accelerate that goal by generating about 3.4 million megawatt hours of renewables by 2015."

Tucson Electric Power is ahead of schedule to meet the state deadline, said David G. Hutchens, president of UNS Energy Corp. TEP's parent company.

"We're actually a little bit ahead of the game right now, which is nice" Hutchens said.

Geisler and Hutchens made their comments in interviews for Arizona Week's Friday broadcast.

Between the two utilities, enough solar generation will be in place by 2015 to serve 100,000 homes and businesses, they said.

APS has built significant solar energy generation facilities near Gila Bend, with two massive arrays of solar panels now in place on hundreds of acres. A third, to be operated by another company with APS purchasing the electricity, will come online soon, Geisler said.

Hutchens said solar is growing rapidly in Tucson, with installation of solar electricity generating systems on 6,000 homes and businesses and another 1,000 being added annually.

Those are thanks in part to tax credits that help both consumers and utilities to venture into renewables, Hutchens and Geisler said.

In Tucson, Technicians for Sustainability, a leading installer of solar hot water and electricity systems is doing about 200 new systems annually, said its founder, Kevin Koch.

"The very first thing that drives the growth is citizen interest," Koch said. "People in Tucson are interested in solar, and they want solar on their homes. They're asking for it. That's the foundation.

"In terms of making it financially accessible to people, the industry is supported by a... tremendous decrease in the cost of equipment as well as an efficiency of installers such as myself bringing our costs to install a system down," Koch told Arizona Week.

"On top of that, still helping to supplement the cost, we have federal tax credits available," he said. "There's a 30 percent tax credit.

"There's a state tax credit of about $1,000 available, and the utilities are still supporting solar through incentives that are funded by a mandate from the (Arizona) Corporation Commission."

More information on solar energy:

U.S. Energy Information Agency Annual Energy Forecast

Solar Energy Industries Association

REhnu Gigawatt Scale Solar is partnering with University of Arizona solar researchers to build and distribute a solar collector array developed at UA's Optical Sciences Department.

UA Tech Park Solar Zone will host several prototypes for testing solar energy designs, producing as much 13 megawatts, enough to serve more than 3,000 homes. The site includes a 1.6 megawatt array operated by TEP.