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Ars Technica reports on a paper investigating how much each power plant contributes to global emissions, using data from 2018. “The study finds that many countries have many power plants that emit carbon dioxide at rates well above either the national or global average.

“Shutting down the worst 5 percent of this list would immediately wipe out about 75 percent of the carbon emissions produced by electricity generation.”
It should surprise nobody that all the worst offenders are coal plants. But the distribution of the highest polluting plants might include a bit of the unexpected.

For example, despite its reputation as the home of coal, China only has a single plant in the top-10 worst (bottom-10?). In contrast, South Korea has three on the list, and India has two. In general, China doesn’t have many plants that stand out as exceptionally bad, in part because so many of its plants were built around the same time, during a giant boom in industrialization. As such, there’s not much variance from plant to plant when it comes to efficiency. In contrast, countries like Germany, Indonesia, Russia, and the US all see a lot of variance, so they’re likely to have some highly inefficient plants that are outliers.

Put a different way, the authors looked at how much of a country’s pollution was produced by the worst 5 percent when all of the country’s power plants were ranked by carbon emissions. In China, the worst 5 percent accounted for roughly a quarter of the country’s total emissions. In the US, the worst 5 percent of plants produced about 75 percent of the power sector’s carbon emissions. South Korea had similar numbers, while Australia, Germany, and Japan all saw their worst 5 percent of plants account for roughly 90 percent of the carbon emissions from their power sector. When it comes to carbon emissions, the worst 5 percent of power plants account for 73 percent of the total power sector emissions globally. That 5 percent also produces over 14 times as much carbon pollution as it would if the plants were merely average…

Simply boosting each plant’s efficiency to the average for the country would drop power sector emissions by a quarter and up to 35 percent in countries like Australia and Germany. Switching them to natural gas, which produces less carbon dioxide per amount of energy released, would drop global emissions by 30 percent, with many countries (including the US) seeing drops of over 40 percent. Again, because China doesn’t see a lot of variance among its plants, these switches would have less of an impact, being in the area of 10 percent drops in emissions. But the big winner is carbon capture and storage. Outfitting the worst of the plants with a capture system that was 85 percent efficient would cut global power sector emissions in half and total global emissions by 20 percent. Countries like Australia and Germany would see their power sector emissions drop by over 75 percent.
Overall, these are massive gains, considering that it’s not unreasonable to think that the modifications could be done in less than a decade. And they show the clear value of targeting the easiest wins when it comes to lowering emissions.

Read more of this story at Slashdot.