Via Lifezette: 

Without coal as backup, attack on key pipelines or hubs could threaten power for millions of Americans

Energy enthusiasts have been rallying around natural gas in recent years as a replacement for coal in generating electricity. And undoubtedly, the fracking revolution has unleashed more natural gas for power generation. But the resulting push toward a greater reliance on natural gas for electricity production at the expense of coal-fired generation could invite troubling, unintended consequences.

In recent years, Americans have rightly become more concerned about threats to the internet posed by cyberhacking, as well as physical attacks on critical infrastructure. From a security standpoint, there are reasons to be particularly worried about the vulnerability of America’s power grid. This concern is one reason why Department of Energy Secretary Rick Perry has commissioned a study on the reliability of the U.S. power grid.

Right now, there are more than 30 natural gas hubs located throughout the United States, each supplied with processed natural gas from an interstate network of pipelines. It is from these centralized hubs that gas is then distributed to regions of the country demanding large amounts of natural gas — for both power generation and residential use.

What’s of particular concern is the centralized nature of this spidery pipeline network. Each hub feeds a limited number of key pipelines across major population centers. A successful attack on one of these pipelines could potentially halt power generation across a series of metropolitan areas.

A good way to envision this is that, while there are plenty of electricity transmission lines strung throughout the country, there are comparatively few pipelines. And while a downed transmission line can be repaired — with electricity re-routed in the interim — the loss of a major pipeline could mean the complete stoppage of gas delivery to multiple power plants.

The vulnerability of these hub pipelines points to a key drawback of gas-fired power. Natural gas plants do not store reserves, and are thus perpetually reliant on the secure delivery of a steady, inflow of fuel.

Such limitations are all the more striking when one considers that much of the nation’s coal fleet maintains a 30-day supply of coal, rendering them essentially independent of day-to-day constraints. If a supply train is late, for example, or a snowstorm delays a coal shipment, the coal plant remains unaffected— and able to keep generating 24/7 electricity for millions of customers.

Both coal and natural gas, though, generate prodigious amounts of power. And such robust delivery shouldn’t be underestimated. A typical 500-megawatt coal plant can provide enough electricity to power 350,000 homes. A 1.5-megawatt wind turbine, in contrast, can power roughly 332 homes. Unfortunately, wind turbines only generate this full “rated capacity” about 40 percent of the time — since the wind doesn’t always blow as needed.

In order to meet the growing power needs of a continually growing population, the United States needs to keep generating ever greater amounts of electricity. As such, the heavy lifting undertaken by coal and natural gas appears more and more crucial. Coal itself still supplies roughly 30 percent of America’s electricity, and the nation’s sturdy coal fleet proved particularly important during the “polar vortex” chill of 2014.

During the coldest parts of that winter, major utility company American Electric Power reported that 90 percent of its coal plants slated for retirement were running at full speed just to meet that peak demand. And even more troubling is that PJM Interconnection, the regional transmission organization in 13 states, has determined that in the event of another polar vortex-type winter, coal plants will be indispensable for meeting peak demand.

All of this begs the question of whether America can simply entrust its future power grid to a greater reliance on natural gas. The possibility of a disruption on a major natural gas hub is a disturbing scenario that must be contemplated and addressed. And so, if the nation wants to move toward increased natural gas power generation, it seems prudent to fully and adequately take steps now to secure the pipeline network currently underpinning much of the country’s power production.

See the article here.