What Electric Utilities Need to Know About Natural Gas Infrastructure

As of July 3, 2017 EPA’s methane leak repair rule appears to be in effect after the U.S. Court of Appeals for the District of Columbia ruled against the Trump administration’s attempts to toss out the rule. Increasingly states are imposing their own leak detection and repair on compressor stations and natural gas pipelines. Even if EPA decides to re-propose a methane rule with far more reasonable compliance dates, maintenance and repairs may still be an issue for some locations.

Utilities should look at three specific concerns in states that already have >60% natural gas generation:

  1. baseload coal plant closure sequencing;
  2. readiness of natural gas storage for utilities to meet winter/summer peak hours under new safety regulation; and
  3. whether gas infrastructure (storage, compressor stations and pipelines) has adequate “work arounds” or gas re-routing to serve power plants during safety or PHMSA/EPA mandated repairs.

The third concern may be the biggest. PHMSA’s new storage safety standards for natural gas storage locations were motivated by Aliso Canyon’s three-month uncontrolled natural gas leak. It is not yet known how many of the nation’s >400 natural gas storage locations might need repairs to meet the new PHMSA standards. In mid-July, the state approved Aliso to reopen but only to operate at approximately 30% of its normal capacity.  If Aliso Canyon’s safety check process is indicative, the six tests took about one month to complete on each well. More than a year after the leak was stopped, only about 34 of the 114 wells are cleared for operation. About 80 more wells await checkup and some will likely need safety upgrades. The nation’s gas storage facilities need similar assessments.

Recently Harvard’s Chan School of Public Health[1] looked at natural gas storage facilities and asserted that many storage locations are designed very similarly to Aliso Canyon’s re-purposed design. The study suggests 210 active but “re-purposed” oil/gas wells are like Aliso Canyon and might be problematic. While we shouldn’t jump to hasty conclusions because there is no indication the other storage facilities and wells are leaking, at a minimum Harvard’s paper begs for more information. Utilities need to better understand their own unique circumstances. Harvard suggests wells in Ohio, Pennsylvania, New York and West Virginia need the highest priority in self-assessments since they don’t have cement zonal isolation methods. I don’t know if Harvard is right or wrong, but their report makes me want to know more about gas storage.

Shouldn’t more be understood about gas storage before making power plant retirement or conversion decisions? Electric utilities have special reliability obligations—serving residential customers, hospitals, data centers, and industrial customers.

Together these considerations suggest utility managers learn more about their natural gas suppliers, gas storage, and the compressor station infrastructure supporting gas delivery to their power plants. Taking a compressor station down might require a methane “blowdown” or safety evacuation affecting pipelines between 5 and perhaps 20 miles away. What happens to the power plant during an unscheduled methane “blowdown”[2] on the pipeline? Is there pipeline re-routing?