The Arizona Corporation Commission has voted to allow Tucson Electric Power to sell more solar energy to the city of Tucson.

The city gets about 4 percent of its power from renewable sources, and the vote will allow it to purchase up to 10 percent of its power from those sources, said Doug Crockett, the energy manager for Tucson.

Tucson Electric Power is now allowed to sell power to the city from a solar-power generating facility northwest of town, in Avra Valley. TEP leases the city-owned land for solar collectors, Crockett said.

“The reason we’re especially interested in pursuing the community solar now is that the options for us to capitalize on future utility rebates that TEP has offered in the past are really diminishing," he said.

The city's ability to add solar to existing municipal buildings is also reduced. It has 500 kilowatts to one megawatt at several buildings, including the Tucson Convention Center, public safety training academy and the Price Service Center.

"We're purposely only subscribing 50 percent of the monthly load, so that we do have an incentive to lower energy use at those sites," Crockett said.

But, solar is not possible on all city buildings.

“We’re really running out of large city facilities with either large rooftops or ground space, simultaneous with large electrical loads, that would justify paying to install the solar ourselves," Crockett said.

Tucson spends more than $30 million on utilities, and about $17 million of that is on electricity, he said.

The city will pay a one-cent premium for the solar power, but won't have to pay two surcharges. Crockett said the city should save money for the 20-year contract for this solar power, because it expects the surcharges to rise. It's the same concept available for homeowners that purchase solar power without generating it on site, he said.

The city can purchase up to 10 megawatts of solar electricity from the Avra Valley generating site.

In addition to saving the city money, Crockett said the agreement with TEP also allows the city to reduce its greenhouse gas generation, which complies with the city-signed Kyoto Protocol.