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Comment by HALtheWise | Hacker News Reader

I viscerally hate this title, because the top 5% of power plants probably also account for >50% of electrical generation, and the entire exercise is dominated by how small of a plant counts for the statistics. If all the portable generators sitting unused in people's garages counted, I bet that 0.1% of "power plants" would be responsible for 99% of emissions, which would make a great headline but still wouldn't tell you anything meaningful about the world.

I would love to know about how efficiency varies with plant size (are bigger plants more efficient?) but this study is _mostly_ just stating that bigger power plants produce more emissions in absolute terms, which should be obvious to pretty much anyone.

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Please read the article. Near the end they delve into details that may interest you.

Quote: “If the top 5 percent of polluters lowered their emission intensity to the global average for fossil fuel plants, the world’s CO2 emissions could drop by 25 percent, the study found.”

So while these plants emit a lot due to their size, they are also much worse (28%-75% per the article) on a co2/kw generated basis as well. (At least according to this article)

> the world’s CO2 emissions could drop by 25 percent

That's impossible, as the total power-generation related emissions count for less than 25 % of the total emissions [1].

[1] https://www.epa.gov/sites/default/files/2016-05/global_emiss...

That is possible, because the article uses 'global emissions' to talk about 'global emissions from electricity generation'.

It's repeated several times through the article, though it may not be super clear. I think they just wanted to avoid repeating themselves all the time

Your assumption is wrong. Reading the linked paper [0], it measures the CO2 output vs energy output (kg CO2 per MWh), and these are indeed hyper emitting plants compared to other similar sized plants. The paper also discusses the capacity of these plants, which is not even close to > 50% of the total electricity generation, as you suggest.

0: https://iopscience.iop.org/article/10.1088/1748-9326/ac13f1/...

The metric used was emission intensities: emissions per unit of generated electricity

"If coal and oil plants in the top 5 percent of polluters switched to natural gas, global emissions would drop by 29.5 percent."

So, if top 5% just switch to natural gas of the same electrical generation capacity, the global emission still drops by ~30%.

https://iopscience.iop.org/article/10.1088/1748-9326/ac13f1/...

Reading the actual study, it does seem their rank for "top 5% polluting" is total emissions. They do calculate relative intensity, as you say. But the ranking for plants with greatest emissions was done without regard for capacity.

Also, the "73%" reduction would only be for GHG's from electricity-generation, not all sources.

I mean, obviously coal is a pretty awful fuel from an environmental standpoint and it's good to quantify these things. Just reading these are hard when the authors didn't necessarily make 100% clear the last few tables.

Ah, you're right. Both top 5% and top 10 plants are selected based on absolute emission amount.

You're absolutely right, and they probably are a significant proportion of generation. However, a key part of optimization is identifying low hanging fruit - replacing (or augmenting) these plants could help reach climate change goals in really short order. Fission is known for being slower to deploy than other green energy sources, but if we could eradicate this carbon source in 5-8 years, then... damn... that's really impressive.

Sadly, I doubt that will happen.

Taken with a grain of salt, this seems to be most of the low-hanging fruit: https://www.scmp.com/news/china/science/article/3140808/chin...

Can you clarify what you are indicating are the low-hanging fruit? Major cities around the world? Or particularly, Chinese cities?

Doing what, though? Because:

> “Another major reason is that many high-carbon production chains were outsourced from developed nations to Chinese cities, thus increasing the export-related emissions of the latter.”

The solution possibly is something more radical than what you're thinking, because the PRC forcing emissions reductions and driving up manufacturing costs could just cause these industries to jump to the next exploitable developing region. I'm thinking more along the lines of strategies to reduce consumerism in general, or match global product prices to their "true" cost considering environmental damage - ideas most pro-infinite-growth capitalists find untenable.

If some country decided that the operation of these power plants was a sufficiently offensive attack, they could bomb them. This would probably be a disaster for quite a few reasons, but it would strongly discourage the plants from operating.

A gentler approach would be a well designed cross border emission tax. This could make operation of these plants economically impractical.

The plants are being run because they are cheap and have plentiful supply, not because they are the most desirable form of production.

Merely adding a new tax would be the most regressive solution available, as it disproportionately hurts the poorest- the consequences would take longer but could end up just as severe. Maybe they dont have access to plentiful natural gas, or grid storage for renewables. Maybe they simply dont have an economy healthy or government free enough of corruption to invest in the capital required to transition.

A more reasonable approach would be to set up a program that fronts the necessary investments while letting the locals retain control... effectively a free loan. It would certainly meet the criterion of "gentler", at least, and probably cheaper than fuelling the planes and the bombs as well- those things are crazy expensive.

Germany, Japan and SK are extremely wealthy countries. I am sure they can manage if they really want to.

Germany in particular made the stupid decision of shutting down nuclear plants (Fukushima overreaction) and it is pushing this narrative of being a green energy country… to me it sounds like an easy problem to solve once there is enough political attention.

Nobody, not even Germans think it is a green country, they aren't pushing that narrative. Who told you that lie?

Most likely you fell victim to American newspapers lying to you that Germany is pushing a green narrative. After all they lied about Germany moving back to coal. What happened is that Germany willingly delayed reductions in CO2 emissions. It clearly cared about the nuclear shutdown more than the coal shutdown. However, the articles are always about how emissions went up "because more coal" when that never happened. It's lies upon lies.

Germany is a country that is standing still, neither getting better nor worse and likes it that way. It's not green and nobody pretended that it is green.

Most countries are very far away for the amounts of renewable production where one needs grid scale storage before being able to build more wind turbines and PV.

How about taking the money to bomb and instead just like... build replacement plants? Why can't we just directly try to make things better instead of trying to punish people (especially who might not actually have the resources/power to do it themselves)?

Not sure you understand how wars and diplomacy work. Remember how 9/11 strongly discouraged global American military and economic power? Neither. Or how Germany was justly punished into submission for causing WWI. They really were humbled into not starting any more wars weren't they?

I am a massive stan for nuclear and alternative, but the most expedient is probably natural gas turbines.

What should have happened 20-60 years ago is modular LFTR reactors, they had them at Oak Ridge. Closet sized reactors could probably scale quickly.

Whenever I hear that China is the biggest polluter, I think that all they need to do is divide themselves into twelve countries, then none of them would be the biggest polluters anymore.

I think that we should be looking at emissions per capita more, but it is still useful to know what countries could have the bigger impact.

Per capita stats are kind of misleading though because China is still an impoverished nation in many parts that can't emit much but still have a massive population. If you just focused on the per capita of the cities (actual developed areas) vs per capita of cities in the US, Europe etc, the story would flip on its head and revert back to it simply being the biggest polluter.

Or they can just stop producing all that junk for the western world.

A reader emailed to suggest a better title, and we've used their suggestion above.

Where are you coming up with this number: >50% of electrical generation of the entire world from top 5% of power plants -- ?? I went to the link and to the linked article, I didn't see anything about >50% generation, or even what is the actual Wh produced by these plants?

Kind of insane the article and the linked discussion don't include HOW MUCH POWER these places make. I've been reading through those two and I can't find that simple fact.

The Accepted Manuscript's original title is:

> Reducing CO2 emissions by targeting the world’s hyper-polluting power plants

https://iopscience.iop.org/article/10.1088/1748-9326/ac13f1/...

The Bełchatów Power Station in Poland has a capacity of 5102 MW, that doesn't even put it in the top 20 largest power stations worldwide.

https://en.wikipedia.org/wiki/List_of_largest_power_stations

The top 20 list here is almost entirely renewables, among coal plants specifically it is the 5th largest in the world.

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