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Dangerous, Dirty Diesels Damage Air and Health, New Study Shows

Jan. 2, 2002

Dangerous, Dirty Diesels Damage Air and Health, New Study Shows

Dallas/Fort Worth Faces Particular Danger: State Implementation Plans at Risk; Groups Outline Needed Changes to Rules and Laws to Clean Up Problem

Fort Worth, Texas – Texas’ plans to reduce air pollution may underestimate a potentially significant and dangerous source of pollution: stationary diesel engines. Public Citizen and the Texas Public Interest Research Group (TexPIRG) released a report today, Micropower at the Crossroads , estimating these diesel generators could add an additional four tons of nitrogen oxides (NOx), a smog-forming chemical, to the air per day in Dallas/Fort Worth, pushing the area beyond its limits to meet federal air quality standards.

Engines like these emit approximately seven times more NOx per hour of operation than a central station power plant. To prevent this source of pollution from becoming a bigger problem, Texas needs to clean up the most polluting of these micropower units, encourage the cleaner sources and fund the cleanest sources of micropower.

“Diesel generators are the forgotten smokestacks of electricity production,” said Tom “Smitty” Smith, director of Public Citizen’s Texas office. “Hidden in our communities – near homes, schools and workplaces – diesel generators pollute more and are regulated less than other sources of power. We estimate that there could be as many as 33,134 diesel generators in Texas.. Assuming average operating and emission rates, these 33,000-plus units could emit 16,000 tons of NOx and 900 tons of sulfur dioxide per year statewide. It is crucial that the Texas Commission on Environmental Quality (TCEQ) regulate these units, lest they sabotage our clean air plans.”

Demand for electricity peaks in the summers, when people use their air conditioners most. Hot summer days are also when air quality is at its worst. Most micropower units currently installed are diesel-fueled and are in place to provide electricity in case of emergency. However, some units may also be used for peak shaving, to provide power on days when electricity costs are high in the summer, to provide stable power, or as primary sources of energy.

“Our fear is that in coming years, should power prices rise or should power quality be threatened, diesel generators like these would be used more and more frequently for peak shaving and grid stability, adding to air pollution and potentially threatening the health of neighbors,” Luke Metzger, an advocate with TexPIRG, said.“We have seen this problem develop in California and other states when power supplies got tight.”

Some diesel generators are used for backup and for peak shaving purposes, but responsible users should avoid using them for peak shaving, Smith said. For example, the JPS Health Network’s six generators could emit up to 18.3 tons of NOx per year. JPS says it has not used its generators for peak shaving anytime in the past two and a half years. Hospitals across the state are looking for ways to reduce power costs, which can be done with clean alternatives. The UT-Houston Health Science Center chose solar panels to offset high electricity prices.

In addition to contributing to smog, diesel exhaust contains more than 40 known carcinogens. The California Air Resources Board estimates that a person’s lifetime cancer risk increases by 50 percent if he or she lives near a single 1-megawatt diesel generator that runs as little as 250 hours annually. “These dangers are unacceptable,” said Smith. “Children and the elderly are the most affected by poor air quality. If our clean air plans overlook these black smoke-belching hotboxes, there’s something wrong with the calculations.”

“What can be done? We have a three point plan,” Smith said. “We need to clean up the old, encourage the clean and fund the cleanest. In 2001, the TCEQ adopted rules regulating new micropower units, but these rules didn’t go far enough. They did not address existing units, an oversight that could allow thousands of units to run on the hottest days of the year. These units could contribute tons of pollutants to the air at the most polluted times of the year in attempts to shave peak power costs or to provide grid stability.”

Public Citizen, Environmental Defense and TexPIRG are planning to file a petition for rulemaking at the TCEQ to close this loophole and require all units used for reasons other than emergencies to meet stringent emissions standards, for the sake of our health. The groups will ask the commission to:

  • limit these emergency back-up units to only 100 hours a year;
  • assure that no units are run for maintenance at times that add to pollution problems;
  • require the use of low sulfur fuels; and
  • dispatch the cleanest units first in cases where the power supply is tight.

The groups also plan to ask the Texas legislature to expand the Texas Emissions Reduction Plan to include stationary diesel engines.

“Some kinds of cleaner micropower, such as combined heating and power or cogeneration, can provide reliable power at low cost,” Buehler said. “Providing power on-site eliminates the need for expensive and unsightly power lines and reduces the burden on the electrical grid, thereby cutting back on the number of large, central station plants that need to run. We hope to see legislation introduced that will encourage the cleaner power sources by assuring fair buy-back rates for excess power and change building and insurance codes.”

“We need to fund the cleanest sources of micropower,” Smith said. “Many types of very clean power are ready to replace these old, dirty units, without the plumes of carcinogenic exhaust: solar panels, small wind, biomass and fuel cells can provide power with far less pollution. Though these new technologies cost more than the common diesel generator today, the lower cost of diesel units doesn’t account for the cost of unhealthy air. We will ask the legislature to establish a program to help introduce these new technologies into the marketplace. We expect that the costs of cleaner sources will drop dramatically, as did the cost of wind power after the state adopted a renewable portfolio standard in 1999. The TCEQ and the legislature should clean up the stationary diesel engines that threaten our health and create new programs to assure that we develop new micropower sources.”  

To view the report on the Web, click here .