Utah's largest oil refinery is getting into the electricity business.

Officials of San Antonio-based Tesoro Petroleum Corp. on Wednesday unveiled plans for a $25 million natural gas turbine generator that will produce roughly 22 megawatts of electricity — enough energy to light up 20,000 homes.

Most of the new electricity will be used to power Tesoro's Salt Lake refinery, capable of processing 60,000 barrels of crude oil a day. Excess electricity will be sold back into the power grid, enough oversupply to power 4,000 to 5,000 homes in the Salt Lake area, said Tesoro chief executive Bruce Smith, who added that the turbine is the first Tesoro has commissioned.

When operational by February, the so-called cogeneration plant will essential eliminate Tesoro's need to buy electricity from Utah Power, which largely supplies most of the state's electricity through coal-burning plants.

In addition, waste heat at a temperature of 920 degrees Fahrenheit from the turbine will be used to produce steam, an essential component in the refining process in producing gasoline, diesel and jet fuel. Because of the steam-producing component, Tesoro will retire the refinery's existing 50-year-old steam boilers.

Tesoro's cogeneration plant marks the fourth in the state, according to Scott Gutting, president of Energy Strategies, a Salt Lake consulting firm.

"This type of project shouldn't be the exception. It should be the norm," Gutting said. "Other states have a lot. Utah is way behind."

About 100 to 150 similar turbines can be found in the western U.S., said Greg Barr, vice president of Solar Turbines Inc., a San Diego company that manufactures and packages the turbines. Thousands more of the turbines exist around the world.

"What's new about the turbines being provided here is the emissions technology. It's the lowest (nitrogen oxide) dry combustion system that we are currently producing," he said, referring to a "greenhouse" gas.

Those environmentally-friendly features seemed to please city officials.

"When people think of cutting-edge environmental practices and technology, the oil industry does not always jump first to mind," said Salt Lake Mayor Rocky Anderson. "The net impact of this facility's operations on global warming through greenhouse gas emissions will be reduced almost to zero."

Another advantage, instead of burning off by-product gases from the refinery's hydrogen-rich fuels, gases now can be used to power the turbine.

"Every time anybody goes by a refinery it's, 'Oh, gee, why don't they do something with that flare.' Now you can," said Quentin Stewart, program manager for Solar Turbines.

Salt Lake-based CEntry Constructors & Engineers, a Layton company, will oversee construction of the plant, which is estimated to employ up to 40 people and 32 engineers.

E-MAIL: danderton@desnews.com