BY DOT SULOCK
Duke Energy has agreed to shut down the plant at Lake Julian that produces electricity by burning coal. That is good news! One reason why this plant will be shut down is that importing coal to provide North Carolina’s power is expensive, and the money spent on imported coal provides jobs elsewhere. North Carolina utilities paid nearly $1.8 billion in 2012 to import 18.7 million tons of coal from six states, mainly from West Virginia and Kentucky (http://avl.mx/299).
If you go to the U.S. Energy Information Agency website about North Carolina (http://avl.mx/29a), you will learn a lot of interesting things about North Carolina. One of the things that you will learn is that North Carolina does not produce natural gas. So if Duke builds a plant burning natural gas to make electricity in Asheville, it will be the same old story. We will have to import natural gas, and the jobs will be elsewhere.
Another reason for terminating the coal-fired plant is that coal puts carbon dioxide into the atmosphere. The plant at Lake Julian has good scrubbers that remove a lot of the particulates from burning coal, but the carbon dioxide is not removed. Each kilowatt-hour of electricity produced by burning coal puts more than 2 pounds of carbon dioxide into the atmosphere (http://avl.mx/29b).
Most homes use 600-1,000 kWh of electricity each month. Since residential electricity costs about 10 cents per kWh, that means the electric bill for these homes is $60-$100 every month. If your electric bill is about $80 per month, you used about 800 kWh of electricity that month, and producing your electricity put about 1,600 pounds of new carbon dioxide in the atmosphere.
So natural gas is “cleaner” than coal, right? Well, when it comes to carbon dioxide emissions, burning natural gas to produce electricity is still putting a lot of carbon dioxide into the air. According to the U.S. Energy Information Agency at the previous link, natural gas puts 1.2 pounds of carbon dioxide into the air for each kWh of electricity generated. So the electricity for the folks with the $80 electric bill each month still puts 960 pounds of carbon dioxide into the atmosphere each month. And then there is the methane.
What’s methane got to do with this? Obtaining natural gas leaks methane. A July 13, 2015, article in Scientific American (http://avl.mx/29c) points out that 1 pound of methane released into the atmosphere will cause the same amount of climate change as 28-36 pounds of carbon dioxide. According to this article, a 2012 study (http://avl.mx/29d) found that natural gas power generation can achieve climate benefits only if methane emissions are kept lower than they currently are. The study found that methane emissions were about 1.5 times EPA estimates, enough to undo the temporarily good effect of less carbon dioxide from natural gas.
Duke can get enough power to replace the coal plant from other plants and new renewables, wind and solar in particular. If you go to this link — http://avl.mx/29e — you can read the petition of Columbia Energy LLC to sell electricity from its existing 523 MW combined cycle-power generating facility to Duke to replace the existing 379 MW coal-fired plant in Asheville that Duke will be shutting down.
There are two big problems with Duke building this unnecessarily large, 752 MW gas-fired plant to replace the 379 MW coal-fired plant. First, the gas-fired plant will keep operating for its lifetime to replace its construction costs even if solar and wind could replace it much sooner.
The second problem is that, as you have probably already realized, the gas-fired plant will put more CO2 into the atmosphere than the coal fired one did: 379 MW x 2,000 pounds of CO2 per MWh burning coal = 758,000 pounds of CO2 going into the atmosphere every hour the coal-fired plant is operating. Plus, 752 MW x 1200 pounds of CO2 per MWh burning natural gas = 902,400 pounds of CO2 going into the atmosphere every hour the gas-fired plant is operating. And add to that the methane emissions from fracking to obtain the natural gas.
Wind and solar are good for the economy of North Carolina. Wind and solar create jobs in North Carolina. Wind and solar do not emit carbon dioxide or methane. If Duke makes a large financial investment now in an unnecessarily large natural gas plant, that plant will have to continue to emit carbon dioxide for many decades to justify its construction. Fossil fuel electricity is obsolete in 2016. Let’s not keep it going in Asheville.
If any of this seems important to you, you can learn more and communicate your opinion to officials by visiting the websites of NCWARN (http://www.ncwarn.org), Mountain True (http://action.mountaintrue.org/page/speakout/fix-dukes-wnc-plan), Canary Coalition (http://www.canarycoalition.org) or Western North Carolina Sierra Club (http://www.wenoca.org).
You can also contact the N.C. Utilities Commission at firstname.lastname@example.org (put docket # E-2 Sub 1089 in the subject line) and express your opinion.
Dot Sulock has been teaching math full time at UNCA for 40 years and teaches about renewable energy at UNCA and the Osher Lifelong Learning Institute.