Abandoning Coal Would Mean Big Strain for U.S. Power Grid
Over-reliance on natural gas as replacement for diverse energy market may endanger supply
There’s plenty of talk these days among energy advocates and environmentalists about the need for natural gas to replace coal as the workhorse producer for America’s daily electricity needs. And coal has undoubtedly been on the ropes in recent years, with both expanded natural gas production and a host of federal regulations cutting coal plants and closing mines. But is the quest to end coal power a sound idea? And can natural gas really supplant coal in providing nationwide base load power generation?
For years, coal produced roughly half of America’s electricity. And it wasn’t until the start of the Obama Administration that the fracking revolution began to unleash more abundant and lower-priced natural gas.
But in tandem with increased natural gas production, President Obama issued a grab bag of federal regulations that greatly hampered coal production. A stringent rule on mercury emissions in 2012 imposed $10 billion in costs, while eliminating roughly 20 percent of America’s coal fleet. A subsequent “Clean Power Plan” in 2015 aimed at ending “carbon pollution” targeted another 25 percent of America’s coal plants. A bureaucratically complex stream rule issued in late 2016 threatened half of America’s coal reserves. And a three-year moratorium on federal coal leases further reduced the nation’s coal supply.
It's no wonder that coal's share of nationwide electricity generation has fallen to roughly one-third of overall power production. But alongside this solid 30 percent, natural gas now supplies another one-third of total electricity, and nuclear power a further 20 percent.
What's particularly relevant here is the concept of "base load power." The United States is a high-energy nation, and it depends on robust power plants to continuously meet minimum daily electricity needs. By and large, these demands are met by a sturdy coal and nuclear fleet.
Why are coal and nuclear so particularly suited to meeting base load power requirements? For one thing, both can run continually, day in and day out, to keep churning out megawatt after megawatt. Part of this ability comes from a built-in benefit of maintaining steady, on-site fuel supplies. A typical coal plant, for example, will stock up on a month's worth of coal at a time — making it a self-contained bunker of ongoing electricity production. Nuclear is likewise self-sufficient — though admittedly more expensive than coal.
The modern U.S. coal plant is also notably cleaner than its predecessors of 30 and 40 years ago. Equipped with expensive, high-tech scrubbing mechanisms and emissions controls, newer coal-fired facilities can trap almost all of the sulfur, mercury, and particulate matter that once plagued the early cities of the Industrial Revolution.
There's still the issue of carbon dioxide (CO2) emissions, though, and concerns about man-made global warming. Encouragingly, newer HELE (high-efficiency, low-emission) coal plants run at higher temperatures and pressures, generating more power and emitting less CO2 per gigawatt generated. It would be nice to see China and India — two countries currently racing to build new coal plants — adopting similar, advanced technologies.
Global warming critics have been quick to demonize coal while enthusiastically urging a brave jump into wind and solar power. Here again, however, base load power matters greatly. Both wind and solar yield only intermittent electricity (because the wind doesn't always blow, and the sun doesn't always shine). And in such cases, grid operators can thankfully call on coal and nuclear plants to ramp up at a moment's notice to supply fill-in power. And so, without such gap-filling assistance from coal and nuclear, the "renewable" adventure of wind and solar would inevitably lead to power shortages and blackouts in heavily taxed grids.
And this brings us to natural gas's emerging role as the presumed steppingstone to a "low-carbon" future. Because natural gas produces less CO2 than coal, environmental advocates see it as the bridge to a "clean energy" infrastructure.
But natural gas has been prioritized for home heating in the United States. And while its share of electricity generation has risen from 17 percent in 2001 to 34 percent in 2016, there are some notable constraints against its mass-adoption.
First, in order to make natural gas the ubiquitous power producer that some envision, the United States would need to build a massive new set of pipeline and delivery systems to accommodate additional power plants. The costs of such investment alone are daunting. But unlike coal supplies delivered by rail, natural gas also remains a high-pressure commodity. The vulnerability of new pipeline systems to extreme weather events, or to malicious attack, means that any service disruptions could interrupt power delivery across wide swaths of the nation.
Natural gas also remains captive to an intricate arrangement of market sales. Grid operators continually hedge their bets in the gas market, splitting their purchases between firm and "interruptible" gas supplies. This can lead to question marks as to whether they have sufficient gas supplies coming in each day to keep power plants running. Typically, natural gas serves as a fill-in producer, supplying extra electricity as needed during peak demand. But such spotty availability would need to be fundamentally revised before the nation could shift away from coal and nuclear power production.
Overall, natural gas now serves as one of a trio of bedrock power producers for America's electric grid. And while natural gas prices have grown more volatile in recent years — and could rise significantly as the U.S. begins to export more supplies to Europe — it supports a diversity of energy production that makes the United States an enviably affluent, safe, first-world nation.
Any rush to completely eliminate coal power and embrace natural gas as the bridge toward a renewable energy future, though, could bump into formidable obstacles. It's admirable to aim for a cleaner energy sector, but real-world problems need to be patiently sorted out, if America is to make such a leap.
Terry Jarrett is an energy attorney and consultant who has served on both the National Association of Regulatory Utility Commissioners and the Missouri Public Service Commission.
(photo credit, homepage image: Joshua Doubek, Wikimedia; photo credit, article image: Ostroff Law)