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Coal Plants Get New Lease On Life With Natural Gas
HughPickens.com writes Christina Nunez reports in National Geographic that in the past four years, at least 29 coal-fired plants in 10 states have switched to natural gas or biomass while another 54 units, mostly in the US Northeast and Midwest, are slated to be converted over the next nine years. By switching to natural gas, plant operators can take advantage of a relatively cheap and plentiful US supply. The change can also help them meet proposed federal rules to limit heat-trapping carbon dioxide emissions from power plants, given that electricity generation from natural gas emits about half as much carbon as electricity from coal does.
But not everyone is happy with the conversions. The Dunkirk plant in western New York, slated for conversion to natural gas, is the focus of a lawsuit by environmental groups that say the $150 million repowering will force the state's energy consumers to pay for an unnecessary facility. "What we're concerned about is that the Dunkirk proceeding is setting a really, really bad precedent where we're going to keep these old, outdated, polluting plants on life support for political reasons," says Christopher Amato. Dunkirk's operator, NRG, wanted to mothball the plant in 2012, saying it was not economical to run. The utility, National Grid, said shutting it down could make local power supplies less reliable, a problem that could be fixed by boosting transmission capacity—at a lower cost than repowering Dunkirk. Meanwhile the citizens of Dunkirk are happy the plant is staying open. "We couldn't let it happen. We would lose our tax base, we would lose our jobs, we would lose our future," said State Sen. Catharine M. Young. "This agreement saves us. It gives us a foundation on which to build our economy. It gives us hope. This is our community's Christmas miracle!"
But not everyone is happy with the conversions. The Dunkirk plant in western New York, slated for conversion to natural gas, is the focus of a lawsuit by environmental groups that say the $150 million repowering will force the state's energy consumers to pay for an unnecessary facility. "What we're concerned about is that the Dunkirk proceeding is setting a really, really bad precedent where we're going to keep these old, outdated, polluting plants on life support for political reasons," says Christopher Amato. Dunkirk's operator, NRG, wanted to mothball the plant in 2012, saying it was not economical to run. The utility, National Grid, said shutting it down could make local power supplies less reliable, a problem that could be fixed by boosting transmission capacity—at a lower cost than repowering Dunkirk. Meanwhile the citizens of Dunkirk are happy the plant is staying open. "We couldn't let it happen. We would lose our tax base, we would lose our jobs, we would lose our future," said State Sen. Catharine M. Young. "This agreement saves us. It gives us a foundation on which to build our economy. It gives us hope. This is our community's Christmas miracle!"
Burning coal is pretty much just turning bulk carbon into carbon dioxide. Burning natural gas (methane, CH4) creates carbon dioxide, too, of course, but also releases energy from burning the hydrogen to make water. As a result, the combustion of natural gas produces less CO2 for the same energy output.
From the Energy Information Agency - Pounds of CO2 emitted per million BTU of energy:
Coal (anthracite): 228.6
Gasoline: 157.2
Natural Gas: 117.0
[I'll apologize for the units - I'm just quoting the result. If you must know, 1 lb / 1e6 BTU is equivalent to 0.43e-3 kg/MJ. Or, just look at the number as a figure of merit: lower is better.]
more data here
That was then. Today we have settled on standardized new-generation plant designs that avoid this problem.
What's really needed is a change in our legal system to eliminate the disproportionate power that small groups of activists have to disrupt construction. Their strategy is to raise costs by imposing phony legal delays on construction after the initial approval.
As a guy who very recently was involved in selling new power station equipment, I can say with 100% confidence that there is no such thing as a standardized power plant design in the USA. I was selling turbines to Duke, Southern Company, Exelon, Luminant, and many others. Every customer wanted something different. Some of them wanted triple redundant instruments on valves, and some were happy with dual redundancy. Some of them wanted the generator protection system to be redundant on 2 different vendor's kit, and some wanted redundancy with identical cabinets from the same vendor. Some wanted a stainless steel oil tank, and some were fine with the carbon steel + epoxy coating tank. Some of them wanted to have a large turbine deck to make maintenance easier, and some were cutting that cost since they were going to flip the plant anyway. We went into great detail about even the most mundane of things. Some of the customers wanted to have all our equipment numbering changed to their (internal and proprietary) numbering standard so that all the plants they owned had the same numbering scheme. No matter what our "standard" design was, someone had a problem with it. These guys know what they want and if it isn't included in your "standard" design, they want a price to make it happen.
This is a different philosophy from Europe and Asia, where standard designs are common and even preferred. But that's the US power market. Toshiba/Westinghouses' standard AP1000 plant isn't good enough for any of the US utilities who can afford to build such a thing. All the customers have their little quirks of wanting to be a little more safe in one area, or a little more convenient to operate, or a little cheaper to build. None of those changes affect the core safety principles of the design, they are just different. They do, however, drive up the build cost. Additionally, these plants don't get build often enough to keep the same crew on each job. By the time you build Unit #2, 10 years has gone by and a lot of the people who built Unit #1 have changed jobs or retired. It is difficult to keep such specialized experience in the economy if it is needed so rarely.
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.