this post was submitted on 04 Sep 2023
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With climate change looming, it seems so completely backwards to go back to using it again.

Is it coal miners pushing to keep their jobs? Fear of nuclear power? Is purely politically motivated, or are there genuinely people who believe coal is clean?


Edit, I will admit I was ignorant to the usage of coal nowadays.

Now I'm more depressed than when I posted this

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[–] tinkeringidiot 18 points 1 year ago (2 children)

Storage. Coal, natural gas, and nuclear generate power regardless of weather, day and night.

Solar generates plenty of electricity (with enough panels installed), but it slows down significantly under cloudy skies and stops entirely at night.

Wind generates plenty as well…unless the wind stops blowing.

The grid needs power all the time, not just when it’s sunny and windy. For renewables to actually compete, the excess power they generate during sunny and windy times needs to be stored for use when it’s dark and still.

As much as we applaud lithium batteries, our energy storage technologies are abysmally inefficient. We’re nowhere near being able to store and discharge grid-scale power the way we’d need to for full adoption of renewables. The very best we can do today (and I wish I were kidding) is pump water up a hill, then use hydroelectric generators as it flows back down. Our energy storage tech is literally in the Stone Age.

[–] [email protected] 7 points 1 year ago (2 children)

Don't underestimate the battery potential of gravity!

According to https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectricity#:~:text=The%20round%2Dtrip%20energy%20efficiency,sources%20claiming%20up%20to%2087%25. The round-trip efficiency of pumped storage is 70-80%, that's pretty darn good for cheap mass-storage. There's not much more to gain there.

[–] [email protected] 7 points 1 year ago

Pumped water is about the only practical gravity battery, but it has limitations.

  1. It can only be built in a few geographical locations.
  2. This tends to limit it's overall capacity unless you're Norway or Switzerland.
  3. It requires flooding an area to make a storage lake and so has a high environmental impact.
  4. Building power stations inside mountains is difficult and expensive.

So it's great stuff, but I don't think it's going to be the backbone of any storage solution we have.

[–] tinkeringidiot 7 points 1 year ago (1 children)

It works very well, not disputing that.

But, like geothermal power generation (which is also very good), it’s extremely dependent on location. Most populated areas don’t have the altitude differential (steep hills) and/or water supply to implement pumped hydro storage.

Where it can be used, it should be (and largely is - fossil fuel generation does better with some storage as well, since demand is not consistent), but it’s hardly something that can be deployed alongside solar and wind generators everywhere.

[–] [email protected] 3 points 1 year ago (2 children)

With some high voltage long-range transmission lines you could viably do it pretty much everywhere. Just requires some cooperation.

Yes it will slightly reduce efficiency over very long distances, but it's not unreasonable amounts.

[–] tinkeringidiot 3 points 1 year ago

Long range transmission of AC power is limited to about 40 miles. DC can be transmitted much farther, but the infrastructure is substantially more expensive (because it’s more dangerous), so that’s only done for extreme need.

We aren’t getting away from having many power generators all over the place, so one location-dependent storage solution isn’t going to solve all the problems.

[–] [email protected] 1 points 1 year ago

I might also add there's smart algorithms being developed for about 5y+ now that distribute power surplus and deficiency over a grid. This will probably be key. Just take a look at "energy metering".

[–] [email protected] 0 points 1 year ago

ah you already beat me to the response, pumped hydro is already utility scale baseline power supply