Comment by jillesvangurp | Hacker News Reader

Comment by jillesvangurp | Hacker News Reader

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Coal + gas is no longer 80% of supply in the US. Your numbers are out of date: https://www.eia.gov/outlooks/steo/report/electricity.php

A lot of coal disappeared in recent years and there are quite a few more coal plants closing soon. Coal is not economical anymore. Even keeping existing plants running has become uneconomical.

So, it's more like 58% for gas and coal combined at this point. Some of the coal capacity is replaced with gas but actually most of it is replaced with wind/solar. Gas is actually declining as well the last few years because not all planned gas plants actually make it to completion and some plants that do get built basically are reduced to the role of a peaker plant that only runs when there's a shortage.

Some plans for new plants actually got shelved entirely and there are also some older plants that are no longer economical that are actually getting shut down. Hence the net decline for gas power generation.

So, take that 40% new gas generation with a grain of salt. That might not actually happen. There might be permits and plans for this but that doesn't mean they'll actually build the plants. My guess is that nobody is in a hurry to build new gas power plants right now given the current gas prices. The cost just doesn't add up anymore relative to cheap wind and solar. Even before Russia invaded Ukraine.

Anyway, according to this, renewables grew from around 5% in 2005 to about 13% this year. It will swap third place with nuclear in a few years and number two position shortly after when coal continues to crash.

People are mixing up multiple different numbers and statistics, one being capacity vs generation, and the other being nuclear missing from both posts.

Nuclear stands for 10% capacity, but 20% generation. It do this because nuclear is expensive to build, but once built the operational costs is fairly fixed with low fuel costs. Fossil fuels plats are generally cheap to build but has high fuel costs, and renewables is dependent on weather. As such they both have higher capacity than generation. Coal is slightly the odd one in the mix in that their capacity and generation is about the same.

In term of energy generated, about 60% is fossil fuel, 20% nuclear, 20% renewables (using 2021 numbers).

In terms of capacity, we have 66% fossil fuel, 9% nuclear, 25% renewables.

The prognosis is that in terms of generated power, fossil fuel will decrease, renewables increase, and nuclear stay about the same with a tiny decrease that is related to the overall increase in energy usage.

The prognosis for capacity is an increase in both fossil fuel and renewables. Coal is and has mostly already been replaced with gas. The total capacity is steadily increasing for fossil fuels, while the renewables are increasing also at a slightly faster speed.

40% increase in fossil fuel capacity is still a very bad thing. If the market is investing in increasing the capacity to burn fossil fuel then there is a reason for it. They are intending to burn fossil fuel, and that for several decades into the future. At the same time we will see a higher portion of the generated energy coming from renewables since it is more economical to generate energy from renewables during optimal weather conditions. Any gas being burned during a windy/sunny day is an unnecessary expensive source of energy, unless the initial construction costs of renewables is greater than the profits of the total periods of optimal weather conditions.

I didnt see where your 40% fossil generation increase was sourced, but if that is being used to replace fossil burning cars and fossil burning heating, then its still a positive. And, if it doesnt actually get used much, thats even better. And, if when it does get used its burning green hydrogen then thats pretty good.

A lot of this is wishful thinking, as are many green initiatives.

Hydrogen is very much not green right now. There's a ton of research into practical green hydrogen but at the moment it's not and it's at least a few years off because you know, research.

Thanks for that link, pretty illuminating.

For anyone curious, breakdown of US power generation in 2021 was (4200 TWh total):

  Coal : 22%
  Natural Gas : 38%
  Nuclear : 19%
  Hydroelectric : 6%
  Other Renewables : 14%

Curiously, hydroelectric power production has been flat for the past decade. Is that because we've already tapped out most places where hydro can be productive?

There are also projects to tear out hydro dams, especially smaller ones, because they are ecologically destructive. So while huge dams may generate enough power to justify the ecological cost, a 1MW dam on some relatively minor river may not justify its existence and so it gets torn back out to enable the river to be restored. You can put a bunch of solar panels on malls and office blocks and make up a big chunk of that power without destroying a river, the malls and offices are already our fault because we put them there, so adding solar panels probably doesn't worsen the impact.

A lot of the small dams are also very old and would require a lot of money to keep them running so just tearing them down often turns out to be cheaper long term.

Two issues with hydro:

1) Most of the obvious places have dams already and building new dams is a combination of expensive and disruptive.

2) Droughts and water shortages make the existing hydro plants less productive. E.g. the hoover dam has some issues with that in recent years.

I found it most interesting that "Other Renewables" (i.e. solar and wind) went from ~5% to ~15% in just 10 years. If we can triple capacity again in the next 10 years, we could completely eliminate coal (assuming storage can solve load issues).

> So, take that 40% new gas generation with a grain of salt.

It's not 40% new gas. It's 40% new "not Solar/ Batteries". From the article:

> The remaining 34 GW of planned capacity additions over the next two years will largely come from natural gas (16 GW) and wind (15 GW)

In both cases these are subject to permission fights, because almost the same NIMBYs who oppose a gas plant will also oppose a wind farm, only the locations and arguments are different because in practice these groups tend to be BANANAs (Build Absolutely Nothing Anywhere Near Anyone).

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