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Comment by barney54 | Hacker News Reader

The LA Times' title for this article is wrong. California does not generate electricity from coal, however, California uses a lot of electricity generated from coal. As the article notes near the end, California uses electricity from coal generated out of state.

According to SNL, "at times, as much as 50% of Southern California's electricity still comes from coal-fired plants, Steve Homer, director of project management for the Southern California Public Power Authority, or SCPPA, told SNL Energy." https://www.snl.com/InteractiveX/Article.aspx?cdid=A-3411331...

This really is a reminder that the writers of articles frequently do not write the headlines. That's a big reason why titles of articles are frequently misleading.

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According to the same source:

> In 2014, less than 5% of California's total energy demand was served by coal and petroleum coke-fired plants, nearly all of it from plants outside the state

Which is followed by what you quoted:

> At times...

So, according to that source, out of state coal consumption can range from 5% to 50%. It doesn't say exactly when the 50% figure was hit, or why.

Peak use vs. average use. A dramatic spike in usage means you need to get power from somewhere (or put up with brownouts), and on occasion that means 50% comes from coal even if it's only for 30 minutes a few times a month.

Stocks versus flows. You integrate power over time to get energy. 5% of the energy comes from coal but up to 50% of the power. That means that much of the time the use of coal power has to be less than 5%. Probably but not necessarily much less.

Can you elaborate? I can't remember that month of Physics when we learned how equations relating to power.

Power is the rate at which energy is flowing. You can get the same amount of energy by either a large amount of power for a short time or a small amount of power for a short time. A way you could have up to 50% coal power but only 5% coal energy is if you use 0% coal for power 90% of the time but 10% of the time use 50% coal power.

Average contribution from coal: 5%

Max contribution from coal: 50%

> So, according to that source, out of state coal consumption can range from 5% to 50%. It doesn't say exactly when the 50% figure was hit, or why.

The quote is from the Southern California Public Power Agency (SCPPA). Their members include LADWP, Anaheim, and other municipal power agencies. The 50% of which he speaks is, like others have noted, for demand (not energy), but only for SCPPA, not all of California. The < 5% is for all of California.

Note that it's 5% for California vs 50% for Southern California.

The reason is pretty simple: California doesn't have many power plants.

I spent a day or two once sifting through California Public Utility Commission archives.

California has not approved a coal plant since at least 1978, mainly due to NIMBY concerns wherever they tried to build them.

I disagree with most things NIMBY, but can you really fault people for not wanting a coal-burning power plant in their backyard given the sheer volume of pollutants released from them? It seems like a great thing that California hasn't approved a new one in 40 years.

Fun fact: a coal plant releases more radiological pollution in a day than a nuclear plant releases in a year.

Fun fact: coal is produces more pollution of all types ranging from radioactivity to CO2 to metals to acid rain generators (SOx/NOx) to ozone (NOx again) to black carbon aerosols (or even black carbon on snow!). Coal extraction is bad for workers and the environment, and it's often dangerous to mine. It is the worst energy technology period.

We're playing stage 3 of Power Grid, and coal is already getting more expensive. Let's just stop burning it now please.

Also we should leave some coal around just in case we destroy society and our descendants need to bootstrap a civilization again. It's hard to do that without an easily accessible fossil fuel.

Measured when and on what coal plant design? It's not like all coal plants can be generalised in such a way.. or can they?

Coal involves burning tons of minerals, concentrating the non-carbon elements of those minerals into coal ash and exhaust. A lot of those other minerals are radioactive or otherwise toxic.

http://www.scientificamerican.com/article/coal-ash-is-more-r...

However, to make a fair comparison you should also consider the toxic byproducts of uranium extraction and purification. Coal is not refined in anywhere near the same degree as reactor-grade uranium.

If you're going to consider those for uranium you also need to consider them for coal.

The energy density of uranium makes it a non-issue. A 1GW reactor fissions about 1 ton of enriched uranium per year. You need about 10x as much raw material, so we're talking about 10 tons of uranium per year.

If you can't reprocess, then you lose about 95% of the fissionable material in the uranium. So you use up 20 tons of material per year, and you need to mine about 200 tons.

In comparison, a 1GW coal plant uses about 3 million tons of coal per year. And be real, coal isn't particularly clean to mine either. You need to wash it, and that water ends up just as polluted with heavy metals as the fly ash. Not to mention the human toll - black lung disease still killed about 25k people in the year 2013, and incidence rates (in the active miner population) have actually been rising since the 1990s.

It's the difference between a small-scale mining operation and large-scale strip mining.

> However, to make a fair comparison you should also consider the toxic byproducts of uranium extraction and purification. Coal is not refined in anywhere near the same degree as reactor-grade uranium.

If I understand correctly, these waste products are liquid or solid that can be stored, rather than dispersed into the atmosphere like coal byproducts. (Of course, storage poses its own technical challenges, like warning people in fifty thousand years not to mess with them, and the Hanford site's current leakage problems.)

Fission by-products include irradiated water, radiactive xenon (a problem as that turns out to be a neutron-absorbant and resulted in unexplained power-loss on early nuclear reactors), and other gasses.

There's a lot of crud they're producing.

http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/xenon.html

The radioisotopes are in the fuel, so it doesn't depend much on plant design. In any case, coal technology is pretty standardized by now.

My understanding is that this is from the radioactive carbon-14 isotope which is in the CO2 emitted, at something like one part per trillion. So it should apply to any non-CCS powerplant.

But it's still misleading, since essentially all of that CO2 will remain in the atmosphere, while radioactivity in the form of uranium, plutonium etc. will all rain down to the ground quickly (i.e. "fallout").

Edit: I remembered wrong, carbon-14 isn't the problem. It's uranium etc. in the ash from coal powerplants. Disregard this post.

Per megawatt: see http://www.scientificamerican.com/article/coal-ash-is-more-r...

That's grossly misleading. The first problem with it, is it assume that coal fired plants release their fly ash up the stocks, they don't, not anymore.

The second problem with it is the radio isotopes are Uranium and Thorium which as far as these things go are a nothing burger. AKA they are very weakly radioactive and they don't bio-accumulate.

Third problem with it is fly ash is about as radio-active as plain dirt. Because dirt also has similar levels of thorium and uranium in it.

At the end of the day, the average person would be more exposed to radioactivity from walking by fly ash (in a pond, in a pile, in the air, wherever it is) than from shielded waste. "[...] fly ash most definitely is not more radioactive than nuclear waste. Instead, I think he is saying that if you stood next to a pile of fly ash you’d probably get a bigger radiation dose than if you stood next to radioactive waste that is adequately shielded." [0]

Also statistics helps frame an accurate picture when looking at it in terms of energy, not mass: "'In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.' Our source for this statistic is Dana Christensen, an associate lab director for energy and engineering at Oak Ridge National Laboratory as well as 1978 paper in Science authored by J. P. McBride and colleagues, also of ORNL." [1]

[0] http://www.cejournal.net/?p=410

[1] Ignore the incorrect headline: http://www.scientificamerican.com/article/coal-ash-is-more-r...

> the average person would be more exposed to radioactivity from walking by fly ash (in a pond, in a pile, in the air, wherever it is) than from shielded waste.

This is wrong because your shielding is radioactive. Concrete is radio active, dirt is radio active, fly ash is radio active. Your granite counter top is radio active.

Fly ash sitting in a landfill has zero radio-logical hazard. Because there isn't anything about it that will increase the local back ground radiation level. And because the radio-isotopes have a zero risk profile.

That same cannot be said for nuclear waste.

That is why the original statement is grossly misleading. And why it pops up again and again like bad penny.

Even more fun - a large portion of that release is aerosolized emissions.

Fun fact: both are utterly fucking irrelevant.

There's a Scientific American article from a few years back which points out that coal ash is radioactive. It turns out that, yes, it is, rather mildly. But it's still thousands of times below the the lowest clinical significant level.

The problem with nuclear arises, say, should a core failure occur the radiation exposure received in a few minutes would exceed that of a very long time (I believe it was millions of years) of fly-ash exposure.

Or, when in normal operation of a nuclear power plant you are creating waste products, including the plant structure itself which are deadly for tens of thousands of years. Far longer than any human institutions or even extant languages.

Of the various noxious consequences of coal-fired power generation (and there are many), radioactive emissions are simply not a concern.

> Or, when in normal operation of a nuclear power plant you are creating waste products, including the plant structure itself which are deadly for tens of thousands of years. Far longer than any human institutions or even extant languages.

So pulverize the nuclear waste product, including the "deadly" plant structure itself, mix with other stuff, and spread it evenly in a large landfill. Or even better, make fine powder and throw it into the atmosphere. With a bit of wind, everything will be well below "lowest clinical significant level."

Sounds horrible? But that's exactly what coal plants do!

Chemist James Lovelock, one of the authors of the Gaia hypothesis, suggested dispersing nuclear waste throughout nature preserves. Animals can adapt to the radiation pretty quickly at low levels and it would discourage humans from developing the preserves.

"The solution to pollution is dilution."

Small amounts of highly radioactive waste are easier to deal with than large amounts of low-level waste. There's also the problem that the ecosystem may concentrate heavy metals, much as aquatic ecosystems do. As you move up the food chain in fish, mercury concentration increases, to the point that swordfish now have a warning.

"Normal radiation emissions" from nuclear power plants do not include decomissioned structures.

You disagree with most things NIMBY because it is generally used as a pejorative. However, the basics of the term is pretty benign.

E.g., people who are pro urban density tend to be NIMBY on things that expand car usage. Then they label anti-density people as "NIMBY", as if that really means anything. The fact is that they're both NIMBY, just on different issues.

Everyone is NIMBY on something.

It's not a great thing to deny new permits and then import the power from out-of-state. It's less efficient because you have transmission losses.

Modern society is pretty cool, but it does have some costs. I have little patience for people who want all the benefits of modern society but none of the costs.

I don't really fault anyone for being opposed to things they don't like in their neighborhood.

The problem is systems that gives property owners a veto over other people's property.

Also, given that coal plants emit huge amounts of CO2, their "back yard" is arguably the entire planet.

> California has not approved a coal plant since at least 1978, mainly due to NIMBY concerns wherever they tried to build them.

This seems like a misleading statistic. Since you have looked at the numbers, how many natural gas power plants were built over the same time period? I can think of at least two just in my county.

> First, the share of California's total megawatt hours of power generated by burning coal dropped from 1% in 2007 to just 0.2% in 2015.

> Second, in a report that the agency released last week, California saw a 96% decrease in coal-fueled electric power consumption during the same time frame. That is the steepest fall by percentage of any state.

That reads to me like the title is correct but incomplete - coal energy production and consumption are both down significantly.

Ok, we've attempted to make the title more accurate. If anybody suggests a better title, we can change it again.

My suggestion: California's minimal coal-generated elecricity imports fall another 96%

Problems with title as it stands:

1. Suggests California has (or had) considerable coal-based generation. It doesn't and didn't.

2. Suggests California's reliance on coal-fired electricity was high. It wasn't.

3. Fails to disclose that a small quantity of imported power has been reduced yet further.

It's actually almost a perfectly anti-informative headline. Reading it you'd form a mental state nearly perfectly counter to reality.

But the article does address both the in-state generation and consumption. It doesn't do a great job of clearly separating the two, but it mentions that both are down dramatically.

Here it explicitly refers to all power fueled by coal as different from power generated by coal in-state:

"Second, in a report that the agency released last week, California saw a 96% decrease in coal-fueled electric power consumption during the same time frame."

And goes into the reasons why this shift is affecting not just in-state generation but consumption of out-of-state coal power:

"“What the bill basically said is, if you’re going to sell power in California, you have to be as clean as the power that we burn here in California,” said Dan Jacobson, legislative director for the advocacy group Environment California."

It even calls out a plant in Nevada as one of the plants providing power to CA that was taken offline:

"For example, the 1,636-megawatt coal-fired Mohave Generating Station in Laughlin, Nev., shut down at the end of 2005. Southern California Edison had a 56% interest in the plant."

Even the article that OP links to supports the LA Times article, rather than refuting it.

We're happy to change the title to a more accurate one, or back to the original if it's best. But we need user help to figure these things out—it's impossible to study all the articles well enough to get the nuances right.

Ok, the original title was accurate and describes what's in the article.

Per the article there is one coal power plant still active.

It's run by Argus (the sometimes good, sometimes bad company from Arrow) near San Bernadino.

Yep. LA uses a lot of power from the Intermountain plant, in Utah: https://en.wikipedia.org/wiki/Intermountain_Power_Plant

Titles are written by click-bait experts.

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