With natural gas prices at their lowest levels in years, Tucson Electric Power Co. hasn't been burning coal at its south-side power plant lately.
Environmentalists want to keep it that way.
On Thursday, groups including the recently formed Tucson Climate Action Network, and the National Institute for Peer Support, demanded that TEP commit to quit burning coal entirely at the mainly natural gas-burning H. Wilson Sundt Generating Station on East Irvington Road, citing the health effects on local residents and the need to slow global warming.
The groups, which also include the Clean Air Task Force, Physicians for Social Responsibility, 350.org and the Sierra Club, called on TEP to switch solely to cleaner-burning natural gas at Sundt. One of Sundt's four generating units can burn either coal or gas; the three others now burn only natural gas though they were built to use fuel oil or gas.
At a small rally in a grassy park near the Sundt plant, organizers cited a report by the Clean Air Task Force that blames coal operations at the Sundt plant alone for serious public-health effects.
The group estimated that as of 2010, particulates from the plant's coal burning was responsible for four deaths, six heart attacks and 68 asthma attacks per year, with those and related ailments costing more than $28 million annually.
Jim Driscoll of the National Institute for Peer Support Climate Project said those numbers are estimated and may seem abstract, but they represent real health effects.
"TEP makes a lot of efforts to be a good citizen, but when they decide they can save money by switching to coal, four people are going to die, and all those other negative effects - that's not being a good neighbor," said Driscoll, a longtime political and environmental activist.
Though about 80 percent of the power TEP generates comes from coal, the company has shown by mainly burning gas at Sundt that coal could be eliminated from the local plant, he said.
"Here it ought to be a no-brainer, so we thought we'd hold it out to them," Driscoll said.
TEP hasn't burned coal at Sundt since last year but the company has no current plan to stop using coal there in the future, TEP spokesman Joe Barrios said.
Coal contributes to a diversity of fuel resources that helps hold down electric rates and ensure system reliability.
"It's not all about price in terms of deciding what fuel to use, but it's certainly a consideration because those costs fall to the customer," Barrios said.
The company has been moving toward more generating resources based on natural gas as well as renewable energy such as solar, Barrios said, noting that the Sundt plant uses recycled landfill gas, and a pending project would use an innovative solar-thermal power system to help run the plant's existing generators. Sundt is powered up mainly during periods of peak power demand or to replace other resources down for maintenance.
Though it is not without its own health effects, natural gas has plummeted in price from more than $10 per thousand cubic feet in 2008 to around $2.50 recently.
While TEP has a large stockpile of coal at Sundt ready for future use, Barrios said a current three-year coal supply contract expires at the end of this year and no decisions have been made on future contracts.
On Thursday, a small but passionate group of local environmental activists gathered to make their demands at Augie Acuña-Los Niños Park, with children playing nearby at Los Niños Elementary School and the Sundt plant's smokestacks in the background.
Nationally, 126 coal-fired power plants are operated in residential areas - with at least 10,000 people living within a three-mile radius - and their health effects fall disproportionately on lower-income and minority neighborhoods, according to SourceWatch, a project of the Center for Media & Democracy.
The group says that 56,609 people live within three miles of the Sundt plant, while 1,947 live within a mile of the plant.
The gathering was called in coordination with "Connect the Dots," a global series of events this week organized by 350.org, a group advocating for awareness and action on global warming and climate change.
The elimination of coal-fired power plants such as the TEP furnace is needed to reduce global warming, though the groups acknowledged that recent research suggests natural gas may be as bad as coal in that regard.
"In the 21st century, Arizona and TEP can do better by focusing on the sun's energy, clean energy, instead of dirty coal," Patsy Stewart of 350.org said.
Though TEP has been recognized for its efforts to boost solar and other renewable energy resources, Driscoll said those efforts fall short. "Those solar things are a drop in the bucket," he said. "TEP's not doing enough, and in that regard, the industry's not doing enough, society isn't doing enough."
While utilities now face stepped-up public and regulatory scrutiny of coal-fired power generation, a federal mandate about 30 years ago pushed the Sundt plant into coal operation.
TEP was ordered in 1981 by the U.S. Department of Energy to convert the Sundt plant to coal-fired capability under the Power Plant and Industrial Fuels Act of 1978, which sought to cut America's reliance on foreign oil amid the energy crisis. That law was rescinded in 1987.
The coal conversion was completed on the plant's Unit 4 in 1988; a project to convert a second unit was later abandoned.
Did you know?
The first generating unit at the Irvington Generating Station went into service in 1958, and three more were added by 1967.
The plant was renamed the H. Wilson Sundt Generating Station in 2003 to honor a former longtime board member.
Contact Assistant Business Editor David Wichner at email@example.com or 573-4181.