A brutal storm ripped through southwestern Minnesota in April and snapped 2,000 power poles. Worthington Public Utilities kept the lights on with a seat-of-the-pants microgrid.
They point to the fact that the affect on equipment has never been studied, and the risks to safety and operations are not well known.
Don Santa, president of the Interstate Natural Gas Association of America, who is also heading up the effort, outlined some of the problems stemming from uncertainty over the quality and composition of imported natural gas in a meeting held at the Federal Energy Regulatory Commission (FERC) in late July:
"In some cases, the tolerances for such compositional variations have not been studied. And perfectly available information has not yet been developed.
"Second, for many customers, particularly residential gas users, the lack of controls or mitigated responses that can be taken should a potentially harmful gas composition make its way to their gas-burning appliances presents an issue.
"Third, there is the effect that rapid changes in the compositional variation of gas could have on the reliability, safety, and integrity of the equipment used by major end-users.
"Fourth, there's the exploration of the role of both historical gas composition variability and regional gas composition differences and how end-users have responded to this to date."
Power Plants: An Operational Nightmare?
To establish a baseline of natural gas quality, the gas industry will have to establish a gas tolerance range for electric generating equipment and a host of other devices in which the higher-Btu LNG, even where blended, may not prove compliant. Many utilities executives are concerned about the costs, as well as other issues.
There already have been instances in which utilities have had to shut down their equipment as a result of inconsistent fuel quality.
In New York, the gas utility KeySpan Energy was forced to shut down a plant several times in 2003 after receiving unprocessed fuel that differed significantly from "what the plant was originally designed to handle," according to a document filed at FERC.
Robert D. Wilson, director of environmental operations at KeySpan Energy, notified FERC on March 22 that "the assumption that existing appliances will not be significantly impacted by gas quality variability would not be prudent and additional technical evaluation is needed prior to drawing any conclusions."
The Edison Electric Institute's Chuck Linderman, appearing at the above-mentioned FERC conference in late July, also raised environmental and structural issues associated with generating plant.
"The environmental side is not as well understood as is the combustion side yet, even though there are, in some cases, continuous emissions monitors on some of these units," said Linderman. "The wrong kind of fuel," he added, "has the potential to create vibration inside the unit. Bear in mind that these are machine-made to very tight tolerances that may create operational difficulties or potential failure of the units."
Impact on Air Emissions
"Certainly," notes Linderman, "with the NOx pressures in this area during the summertime and on the East Coast as a whole, we don't want to do anything inadvertently that raises NOx limits or creates units that are out of compliance with the Clean Air Act in the midst of a heat storm."
At the FERC meeting, Linderman reported that