This is Part 2 of the article, “Is “clean coal” a scam or a legitimate solution?”. To read Part 1: The Problems With Coal – Click HERE
Environmental impacts of “clean coal”
Now that you understand the problems with coal, let’s talk about “clean coal.”
There is, unfortunately, no one exact definition of this term. Sometimes, it is used very broadly to refer to things that are now fairly standard practices in modern power plants, such as washing coal to remove dirt and chemical impurities, as well as scrubbers like the nitrogen and sulfur scrubbers that I talked about earlier.
By that definition, however, “clean coal” is anything but clean, because it still has the environmental problems that I talked about earlier.
Yes, the emissions of some (but not all) potentially dangerous gases are reduced, but those emissions aren’t fully eliminated. In fact all of the harmful mining practices are still in place, and massive amounts of CO2 are still released. So, that usage of the term is really just a scam by politicians and companies to make their product sound benign when it is actually still quite harmful.
Yes, those plants are better than ones that don’t use any scrubbers, but they are still a far cry from anything worthy of the title “clean.”
That broad definition is, however, probably not the most common modern usage of the term “clean coal.”
The more common and technical usage generally refers to “carbon capture and storage” (CCS) methods. There are a variety of CCS methods used, and I won’t bore you with the details, but the basic concept is simply that you trap the carbon dioxide from the coal, and you store it somewhere (usually buried deep in the ground) rather than allowing it to be released into the atmosphere. T
his sounds great, but as you have probably guessed, there are a lot of problems with it.
First, it only deals with the carbon dioxide that is produced by burning the coal.
So, all of those other problems that I talked about still exist. All the erosion, stream pollution, lung cancer, etc., is still there. In fact, those problems become even worse!
You see, CCS methods are not energy efficient. As a result, using them requires anywhere from 16–41% more fuel (depending on the type of CCS) than a regular coal plant uses to produce the same amount of power (Rubin et al. 2007; Rubin et al. 2015).
That means more mining, as well as more emissions for gases other than CO2. As a result, environmental issues other than CO2 are worse with CCS than with regular coal power plants (Viebahn et al. 2007; Cuellar-Franca and Azapagic. 2015).
In addition to all of that, CCS technology only removes 90% of the carbon (Rubin et al. 2007).
Much like the nitrogen and carbon scrubbers I mentioned earlier, that’s good, but that 10% is still a lot of CO2, and, just to be clear, it is a lot more CO2 than we produce from renewable energy sources like solar or wind.
It’s more than the carbon footprints from things like constructing renewable energy sources; Viebahn et al. 2007). Further, once the carbon has been trapped, it has to be transported to wherever it is going to be stored, which also uses energy and releases CO2.
Plus, extra fossil fuels are required to mine the extra coal that we need since CCS plants are less efficient. So the net reduction in CO2 drops from 90% to 86–88% (Rubin et al. 2015). Additionally, although the extra CO2 is buried underground, some of it still slowly leaches out of the ground and enters the atmosphere (Viebahn et al. 2007).
So, when it’s all said and done, CCS plants produce less CO2 than regular coal plants, but they still don’t even approach being truly clean, they still have a much bigger carbon footprint than renewable energy sources, and there are still tons of other environmental and safety problems. Indeed, “clean coal” makes those problems worse, not better.
Economics of “clean coal”
Beyond the environmental issues, there is another massive problem with “clean coal.”
It’s freaking expensive. In addition to the cost of installing the CCS technology, you need more coal to produce the same amount of energy, and, once you’ve trapped the CO2, you have to pay to transport and store it.
As a result, CCS plants are 39–78% more expensive than traditional coal power plants (depending on the type of CSS). Indeed, “clean coal” is so expensive that there are currently only 21 operating CCS power plants in the entire world, even though we have had this technology for decades (to be fair, several other plants are currently under development).
In the interest of fairness, I should make two caveats here.
First, some people are experimenting with carbon capture and utilization (CCU) systems, where the carbon is used, rather than stored. This does reduce the cost, but probably not by enough to be meaningful because production of CO2 is expected to far exceed demand (Dowell et al. 2017).
Second, like with any technology, the cost will come down with more research and widespread use. However, it needs to come down a lot for it to be economical, and the price tag for that research and development is quite high.
Indeed, it’s estimated that we would need to invest $100 billion annually to get this technology where it needs to be.
Before ending this post, I do need to acknowledge one other group of technologies that are sometimes referred to as “clean coal.”
These are technologies that focus on burning coal in more efficient ways that reduce the amount of emissions that are produced, rather than technologies that capture the CO2 after it has been released (for example, the DICE project in Australia).
These projects still aren’t really “clean coal” though. “Cleaner” perhaps, but not clean. They still produce lots of CO2, and they still have all the issues with mining that I already talked about, as well as issues with emissions other than CO2.
A recent issue of Popular Mechanics may have said it best when it refereed to “clean coal” as, “a political pipe dream.”
It is far more expensive than regular coal, and it’s not even clean! It does reduce the amount of CO2 that is released into the atmosphere, but it does not eliminate the release of CO2, and it is less efficient than regular coal plants.
As a result, it requires more coal to produce the same amount of energy, which means that we have to mine even more coal, and coal mining causes a wide range of environmental and health problems including water pollution, deforestation, lung cancer, etc. So when you add all of that up, “clean coal” is an expensive misnomer, not a viable solution.
It’s not clean, and it’s not economically practical.
I promised that I wouldn’t get political, but I do want to leave you with a question to ponder. Namely, if we are going to invest money into cleaner energy technologies (as we need to do), then wouldn’t it make sense to invest that money into the technologies with the fewest impacts on the environment and human health?