CO2 emissions are a large concern for citizens around the world, and electricity generation plays a major role in the amount of CO2 emissions that are emitted -- both worldwide, and in the United States. In fact, in recent years, electricity generation has made up about 25% of the total CO2 emissions released in the United States.
Even with the push to close old and inefficient coal plants in favor of cleaner renewable energy facilities, the US still released an estimated 1,530,222,205,474.04 kilograms of CO2 emissions from electricity generation (equivalent to the annual emissions of 332,657,001.19 passenger vehicles) in 2020.
One of the more interesting facts about electricity-caused CO2 emission levels is that roughly 42.92% of the emissions came from just 100 power plants out of the 10435 power plants in the United States. You read that right, 0.96% of power plants in the nation accounted for 42.92% of the emissions released from electricity generation in the US. Even though they are larger than average plants, they are still producing significantly more than their share of emissions due to a severe lack of emissions efficiency when compared to other US plants. Most of this lack of efficiency is the result of their choice of fuel types, such as coal and other fossil fuels. The advanced age of these plants is another contributing factor, as they sometimes don’t take advantage of modern-day energy-efficient equipment and methods.
This trend isn’t isolated in the United States, either. Worldwide, the top 5% of polluting power plants account for 73% of global emissions from energy creation. All of these plants are coal-fired and they exist across a diverse range of countries, such as Poland, South Korea, China, and Germany.
As the United States (and the world as a whole) attempts to lower CO2 emissions, it is important for us to truly grasp the impact of the information presented in the previous paragraphs. The fact that only 100 power plants can have such a large impact on total emissions in the United States is astounding.
For individuals and agencies who wish to lower CO2 emissions, it is common to suggest lowering the footprints of individuals, typically by reducing personal energy consumption and switching to electric vehicles. These changes will certainly contribute to the bottom line, but they may not be the best place to focus our energy. Instead, if we really want to lower CO2 emissions, we may be better served by closing and replacing the plants on this list and others like them.
As these power plants are closed, it is important to continue paying attention to the fuel types that will be used in the new facilities that replace them. The data clearly shows that coal is the worst offender. However, coal power plants are regularly replaced by natural gas power plants, which carry their own environmental concerns.
Natural gas carries approximately half of the CO2 emissions per Metric Million British Thermal Unit (MMBtu) that coal does. This is definitely a step in the right direction. Many renewable fuels and nuclear power are considered carbon neutral but even considering life-cycle emissions natural gas still emits...
- 5 times more emissions than solar (including emissions from the construction of solar materials)
- 7.5 times more emissions than conventional hydroelectric
- 15 times more emissions than nuclear power
- 16 times more emissions than wind-powered turbines
Additionally, fracking, one of the processes used to search for and extract natural gas, is one of the most environmentally damaging practices of the modern energy industry . It is surprising then, to realize that natural gas is regularly referred to as "clean" energy . Keen observers will also note that “clean energy” does not have a technical definition that a company would have to abide by. However, renewable and nuclear energy both have clear definitions that are understood by the majority of the general public. The ideal method for reducing CO2 emissions would be to move towards all electricity generation coming from renewable or nuclear energy plants.
For now, as coal plants are closed and replaced by mainly natural gas and some renewable energy facilities, we should see an overall reduction in emissions in the United States. But will it be enough?
Top 100 Dirtiest Power Plants in the United States
|Rank 2020||Rank 2019||Name||City/County||State||Top Fuel Types||MWh Generated||CO2 Emissions||Emissions per MWh Generated||Equivalent Passenger Vehicle Emissions||Age of Plant (years)||Scheduled Closure Date||Toxic Release|
|Franklin County||MO||Coal (99.95%)|
Distillate Fuel Oil (0.05%)
|2||1||Jefferson County||AL||Coal (98.68%)|
Natural Gas (1.32%)
Distillate Fuel Oil (0.00%)
Martin LakeVistra Energy (100.00%)
|Rusk County||TX||Coal (99.92%)|
Distillate Fuel Oil (0.08%)
Monroe (MI)DTE Energy (100.00%)
Petroleum Coke (5.19%)
Distillate Fuel Oil (0.18%)
Oak Grove (TX)Vistra Energy (100.00%)
|Robertson County||TX||Coal (99.25%)|
Natural Gas (0.75%)
|6||7||Gallia County||OH||Coal (99.91%)|
Distillate Fuel Oil (0.09%)
|7||9||Gibson County||IN||Coal (99.68%)|
Distillate Fuel Oil (0.32%)
W A ParishNRG Energy (100.00%)
Natural Gas (9.29%)
|9||12||Sweetwater County||WY||Coal (99.94%)|
Distillate Fuel Oil (0.06%)
FirstEnergy Harrison Power StationFirst Energy (100.00%)
|Harrison County||WV||Coal (99.87%)|
Natural Gas (0.13%)
Distillate Fuel Oil (0.12%)
Prairie State Generating StationIllinois Municipal Electric Agency (15.17%)Wabash Valley Power Association (2.65%)Indiana Municipal Power Agency (12.64%)Missouri Joint Municipal Electric Utility Commission (12.33%)Southern Illinois Power Cooperative (7.90%)American Municipal Power (23.26%)Prairie Power Inc (8.22%)Northern Illinois Municipal Power Agency (7.60%)Kentucky Municipal Power Agency (7.82%)Lively Grove Energy Partners LLC (2.41%)
|Randolph County||IL||Coal (99.63%)|
Natural Gas (0.37%)
John E AmosAmerican Electric Power (100.00%)
|Putnam County||WV||Coal (99.49%)|
Distillate Fuel Oil (0.51%)
|14||19||Fayette County||TX||Coal (99.81%)|
Distillate Fuel Oil (0.19%)
Cumberland (TN)Tennessee Valley Authority (100.00%)
|Cumberland City||TN||Coal (99.23%)|
Distillate Fuel Oil (0.77%)
Distillate Fuel Oil (0.18%)
Distillate Fuel Oil (0.11%)
Waste/other Oil (0.01%)
|18||21||Brilliant CDP||OH||Coal (99.59%)|
Distillate Fuel Oil (0.41%)
|19||36||Trimble County||KY||Coal (93.64%)|
Natural Gas (6.36%)
Distillate Fuel Oil (0.00%)
|20||26||Emery County||UT||Coal (99.85%)|
Distillate Fuel Oil (0.15%)
Comparison of Emissions
To better understand the lopsidedness of the amounts of the emissions being released by these 100 power plants, when compared to the rest of the plants in the United States, it may be easiest to take a look at a few comparisons below.
If the 100 Dirtiest Power Plants are stacked side by side with our most efficient electricity plants, the following facts come to light. The “100 Dirtiest” plants produced 773,430,169.24 megawatt-hours and released 656,833,719,803.18 kilograms of CO2 emissions in 2020. In order to produce the same amount of megawatt-hours, the most efficient plants would only release 2.98% of the emissions that are released by the “100 Dirtiest”.
From another perspective, if we ran the most efficient plants non-stop until they produced the same amount of emissions as the “100 Dirtiest”, the efficient plants would generate more than 33 times the number of megawatt-hours as the dirty plants. These observations get even more extreme as we look at the top 50, the top 10, and the worst offender, Labadie.
Next, let’s take a look at how our dirtiest plants stack up against other countries as a whole. The “100 Dirtiest” power plants in the United States produce more CO2 emissions than the entire emissions totals (not just electricity generation) of all but seven countries. That’s right, if our top 100 dirtiest power plants were their own country, they would be the 8th largest polluting country, when it comes to CO2 emissions, in the world. Additionally, the Top 50 Dirtiest Plants would be the 15th largest polluting country.
The “100 Dirtiest” plants are a huge hindrance to our overall national CO2 emissions totals. In fact, these 100 plants produce only 19.23% of the electricity generated in the United States, while emitting 42.92% of the emissions from electricity generation in the country. The emissions total of 656,833,719,803.18 kilograms of CO2 gases released from these plants is equal to the annual emissions released from the use of 142,789,939.09 passenger vehicles.
In 2019, there were only 108,547,710 passenger vehicles registered in the United States. While total transportation emissions are regularly as high as emissions from electricity generation, it may be a higher impact effort to work towards replacing electricity from the 100 largest offenders, rather than try to change the habits of millions of Americans who rely on personal vehicles on a daily basis.
So just how bad for us and our environment are the CO2 emissions from electricity generation? This question is especially pertinent to citizens living in the areas directly around fossil fuel power plants, and especially those living near the plants that appear in our “100 Dirtiest” list. Unfortunately, there is no easy way to answer this question. We are all used to seeing the smokestacks of power plants billowing out CO2 and other byproducts of electricity generation into our atmosphere. In fact, it is safe to say that most of us are numb to it.
So what would get our attention? What if these byproducts were pumped into a sealed enclosure. For example, let’s imagine they were released into a giant football stadium. We crunched the numbers and chose one of the largest stadiums in the United States, AT&T Stadium in Dallas, home to the Dallas Cowboys. CO2 is toxic at 100,000 parts per million, AT&T Stadium is 104,000,000 cubic feet, one kilogram of CO2 is 19.253 cubic feet and combined emissions of the "100 Dirtiest" plants in 2020 was 656,833,719,803.18. Using this information, we can come to the conclusion that if the “100 Dirtiest” power plants had their smokestacks redirected and pumped directly into AT&T stadium the air inside would reach a toxic level for everyone in the stadium in just 26 seconds! That's right, these power plants could fill this 100,000 person capacity stadium to the level of toxicity over 1.2 million times a year! The top 50 "Dirtiest" would achieve the same outcome in just over 40 seconds, the top 10 "Dirtiest" in approximately 2 minutes and 10 seconds and the worst polluting power plant of them all, Labadie, in Franklin County, Missouri, would bring the air in the stadium to toxicity in just 17 minutes. Even a single power plant could fill the stadium to toxicity over 30,780 times in a single year.
What Would it Look Like if the 100 Dirtiest Plants Made a Change?
Let’s try some other “What if?” thought experiments. What if the power plants on our “100 Dirtiest” list were able to make some major changes and lower their emissions per megawatt-hour towards a normal level? We can start with the extreme. What percentage of reduction in emissions would we see if all of the “100 Dirtiest” plants were replaced with nuclear or renewable power plants? The “100 Dirtiest” plants average an emissions rate of 849.25 kilograms per megawatt-hour, while nuclear plants average 36.77 kilograms, and renewable plants average 109.74 kilograms per megawatt-hour. These changes would result in a 95.67% reduction in CO2 emissions for a change to nuclear and a 87.08% reduction with a change to all renewable energy.
Or, what if these power plants simply reduced their emissions rate to the national average emissions rate of all power plants in the United States? That average rate currently sits at 454.7 kilograms per megawatt-hour, which would amount to a 46.46% reduction in total emissions.
Let’s keep this thought experiment going to look at some more attainable outcomes.
What if our “100 Dirtiest” all switched their entire production to natural gas instead of coal and oil products? The national average emissions rate for natural gas power plants is 401.25 kilograms per megawatt-hour, which would be a 52.75% drop in the total emissions released by these plants.
Finally, let’s end with an easy one: What if these plants simply set a goal of reaching the average emissions rate of all fossil fuel plants? Not the average of all plants, which would include renewable plants. Just the average for other fossil fuel plants. That average currently sits at 699.69 kilograms per megawatt-hour produced. This would still be a 17.61% decrease in CO2 emissions, simply by striving to be the average of the fossil fuel crowd.
What Fuels Are Powering The 100 Dirtiest Power Plants?
Not surprisingly, coal makes up a vast majority of the fuel that is used in the 100 dirtiest power plants in the United States. Additionally, the power plants on this list use natural gas and petroleum coke. Large inefficient coal plants and those using other fossil fuels, such as natural gas and petroleum coke as their primary fuel make up the entirety of this list of the 100 worst offenders.
Sadly, many of the largest electricity providers in the country have at least some blame to take, as most of the list of biggest offending power plants are owned by these companies. Fortunately, some of these power plants are already scheduled to be closed in the future. The country’s biggest electricity providers and governing US bodies could drastically reduce CO2 emissions from electricity generation if they worked towards an expedited replacement of more of the plants on this list.
Who Owns These Power Plants?
There are 122 separate companies that have ownership stakes in one or more of the “Top 100 Dirtiest” plants. Of these, 27 are investor-owned companies, 25 are owned by municipalities, 22 are cooperatives, 3 are state-owned, and 1 is a federally owned. The company with ownership in the most plants appearing on this list is Duke Energy, with full or partial ownership in 10 of the 100 dirtiest power plants.
Other major offenders include Vistra Energy, with ownership in 7 plants, American Electric Power, with ownership in 7, Berkshire Hathaway Energy with ownership in 7 and Southern Company, with ownership in 7 plants. Of the 100 dirtiest power plants, 38 are owned partially or fully by one or more of only five different companies.
While the number of plants a company has ownership in may tell part of the story, potentially a better question to ask is what companies own the largest percentage of the emissions from these "100 Dirtiest" plants. To figure this out, we took the emissions level from each of the power plants that made this list and assigned it based on ownership percentages to the various companies that own each plant. The results can be seen in the table below.
|Emissions Rank||Company Name||Emissions from Ownership in Dirtiest Plants||Production from Ownership in Dirtiest Plants||Emissions per MWh Generated|
|4||American Electric Power||29,608,356,904.5kg||30,075,812MWh||984.5kg/MWh|
|5||Berkshire Hathaway Energy||28,272,807,695.8kg||27,566,353MWh||1025.6kg/MWh|
|8||PPL Electric Utilities||24,463,599,015.7kg||24,735,687MWh||989.0kg/MWh|
|14||Tennessee Valley Authority||13,343,893,555.5kg||13,186,962MWh||1011.9kg/MWh|
|15||Associated Electric Cooperative||12,446,649,481.1kg||13,064,148MWh||952.7kg/MWh|
|18||Basin Electric Power Cooperative||10,093,976,362.5kg||9,579,101MWh||1053.7kg/MWh|
|19||WEC Energy Group||10,004,020,769.2kg||11,052,315MWh||905.2kg/MWh|
Age of Power Plants
Coal power plants have an average lifespan of 46 years. Many owners of coal plants extend these lifespans by making upgrades or replacing equipment that is no longer efficient or functioning. This practice, however, still may result in less efficient power plants, meaning more pollution emitted per megawatt-hour generated than alternatives.
It is safe to say that the older a fossil fuel-powered plant gets, the less likely it is to be running efficiently. As the fleet of coal-powered plants located in the United States continues to age, it is likely that we will continue to see this same drop in production efficiency when it comes to CO2 emissions. In the chart in this section you can see a breakdown of the average ages of the power plants that appear in the “Top 100 Dirtiest Plants” list.
Plants Scheduled to Close
As we previously mentioned, one of the surest ways to decrease CO2 emissions caused by electricity generation is to replace the production of the dirtiest power plants that are still open. This is often a long process, as the electricity generated at these plants must be replaced by new sources. While some of the “100 Dirtiest” already have retirement dates, many do not. Of those that do have a date already set, some have retirement dates that are a decade or more in the future. This is better than nothing, but we would love to see more of these plants being closed and at a faster pace. Here is a breakdown of the scheduled closure dates of all of the power plants in the “100 Dirtiest” list.
Where Are The 100 Dirtiest Power Plants
Above you can see a map of the “100 Dirtiest” power plants in the United States. With a quick glance, you can begin to see states and areas of the country where emissions restrictions may not already be in place. As far as proximity goes, those living closest to the “100 Dirtiest” plants’ locations should be the most concerned. In addition to CO2 emissions, coal power plants (which make up a vast majority of this list) also pollute their surroundings with fine particle pollution. Fine particle pollution is made up of small pieces of fly ash and dust that are expelled during the process of burning coal. These particles are directly linked to numerous underlying health issues, such as chronic bronchitis, asthma attacks, heart attacks, and, unfortunately, death. Additionally, the World Health Organization’s International Agency for Research on Cancer has labeled “particle matter” as a Group 1 human carcinogen.
While 32 different states have at least one power plant in our “Top 100 Dirtiest Power Plants” list, the states with the most plants appearing on our list are Florida, with 9 power plants in our “100 Dirtiest”, Texas, with 9 plants, and West Virginia, with 7 power plants. Emission levels on a state-by-state basis vary quite significantly. You can see this in the table below, which features the top five dirtiest power plants (as measured by CO2 emissions) for each state.
|State||Plants||Emissions from Top 5 Plants||% of Total State Emissions from Top 5 Plants||% of Total State Production from Top 5 Plants||Emissions per MWh Generated||Equivalent Passenger Vehicle Emissions|
Oak Grove (TX)
W A Parish
Fayette Power Project
Gavin Power, LLC
W H Sammis
W H Zimmer
H L Spurlock
Mill Creek (KY)
FirstEnergy Harrison Power Station
John E Amos
Pleasants Power Station
FirstEnergy Fort Martin Power Station
J H Campbell
Midland Cogeneration Venture
Dearborn Industrial Generation
James H Miller Jr
H Allen Franklin Combined Cycle
E C Gaston
Hillabee Energy Center
West County Energy Center
Hines Energy Complex
Stanton Energy Center
Laramie River Station
Dry Fork Station
McIntosh Combined Cycle Facility
Wansley Combined Cycle
Prairie State Generating Station
Baldwin Energy Complex
E D Edwards
Milton R Young
Intermountain Power Project
Lake Side Power Plant
York Energy Center
Lackawanna Energy Center
Homer City Generating Station
James E. Rogers Energy Complex
Sherwood H Smith Jr Energy Complex
Elm Road Generating Station
Port Washington Generating Station
South Oak Creek
Jeffrey Energy Center
Lawrence Energy Center
As you have read in previous paragraphs, the "Dirtiest Plants" in the United States make up a lopsided proportion of the overall pollution of the electricity industry when considering their megawatt hour production amounts. The "Dirtiest Plants" account for 42.92% of emissions and only 19.23% of production. Predictably, the same trend can be seen in most states throughout the country. However, it is interesting to note some of the worst offenders while also pointing out those states that don't suffer from this trend.
The states of New Hampshire, Massachusetts, and District of Columbia all have power plants that pollute, but the major difference between these states compared to the rest of the country is that the pollution from their worst polluting plants is actually in proportion with the amount of electricity that those power plants produce. While we'd love to see the emissions totals lower than they are, at least these states are not suffering from the production inefficiencies that the country as a whole is. On the other end of the spectrum, the states with the worst efficiency rates in their most polluting plants are Kansas, Vermont, and Tennessee. These states all have plants that pollute amounts significantly higher than their "fair share" based on their production totals. Take Kansas for instance. The "Dirtiest Plants" in Kansas are Jeffrey Energy Center, La Cygne, Lawrence Energy Center, Holcomb, and Nearman Creek. These five power plants are responsible for 88.64% of the CO2 emissions in the entire state of Kansas. You'd expect that if they were responsible for that much of the pollution they must at least be making a majority of the electricity in the state, right? Wrong. These same five power plants produce just over 31.47% of the total electricity generated in the state. Improving the efficiency of, or better yet, closing the doors of these five power plants while opening other plants that operate on more efficient fuel types would significantly alter the CO2 pollution picture in the state of Kansas.
The data doesn’t lie. If the United States intends to get serious about reducing C02 emissions, the problem of our 100 Dirtiest Power Plants needs to be addressed in a more substantive way. Changes in personal energy consumption habits can go a long way towards bringing down our country’s total CO2 emissions, but they can’t fix the problem of our 100 Dirtiest Plants. To truly reach its clean energy goals, the U.S. will need to create and execute a more complete strategy for resolving the massive amount of CO2 released by the plants featured throughout this article.
- Estimation based upon data release by the EIA (https://www.eia.gov/electricity/data/eia923/), the EPA (https://www.epa.gov/sites/production/files/2020-04/documents/ghg-emission-factors-hub.pdf) and https://www.parliament.uk/globalassets/documents/post/postpn268.pdf^
- This number was calculated using a combination of data that is released annually by the EIA that can be found at https://www.eia.gov/electricity/data/eia923/ as well as other sources referenced in this list^
- Dirtiest refers to the most CO2 emissions from an individual power plant. Emissions data is based upon EIA Form 923 (https://www.eia.gov/electricity/data/eia923/), EIA Form 860 (https://www.eia.gov/electricity/data/eia860/), and EPA emissions factors (https://www.epa.gov/sites/production/files/2020-04/documents/ghg-emission-factors-hub.pdf)^
- Calculations were made using ppm toxicity guidelines at https://www.cdc.gov/niosh/idlh/124389.html^