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Comment by yread | Hacker News Reader

And can you switch it on when you need to cover the peak of electricity consumption like with a dam? No. You need a gas turbine.

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You need a gas turbine.

Or a battery.

Or a (pumped-storage) hydroelectric plant, to take the discussion back (almost) full circle.

Or "a single GE Haliade-X wind turbine can output 14MW at peak."

You want some storage for when the wind isn’t blowing.

, for which you don't have to destroy a river habitat.

Nope. Most buffering in the US as deployed is natgas, not poison the water lithium.

Isn't it a choice of "poison the water" or poison the air? Are we under the assumption that natural gas is clean?

I was sardonically calling out that a lot of the energy picture is much more complicated than that.

The battery production process (and PV production process) is quite ecologically intensive, and large portions of the reduction in prices we've seen has been by manufacturing in places that don't exactly have high standards for these things.

No power plant works in a vacuum. Nuclear power plants require a connection to the grid to stay functional, as the biggest one in Europe has shown.

> Nuclear power plants require a connection to the grid to stay functional, as the biggest one in Europe has shown.

Not the case for all Nuclear, just really old nuclear. All the ones in Canada (CANDU reactors) have the rods suspended by electromagnets, if the station stops producing power, they drop into the reactor, ending criticality. They also use unenriched uranium (or plutonium or thorium).

Most large power generation facilities must be connected to a load (grid) to operate, nuclear or not.

To operate yes... but to keep safe when the grid goes out? Only NPPs require a permanent grid connection to not blow up. That is the key issue with the Zaporizhzhia NPP - it has been shut down for months, but still the rods need to be cooled, and it's a massive logistical challenge and an absurd amount of risk involved in keeping the grid connection alive and the backup generators supplied with diesel fuel.

> NPPs require a permanent grid connection to not blow up

There is no risk of nuclear power stations blowing up if a power cable breaks!

> Only NPPs require a permanent grid connection to not blow up.

This is untrue, and in the next sentence you contradict this statement when you mention the backup to the power grid: diesel generators which are substantially more portable, and less powerful than an entire energy grid.

“Connection to the grid” versus “storage capacity that doesn’t exist yet” is quite a difference.

Oh no. We have to keep the thing powering the grid connected to it. This will be such a huge logistical hurdle. /s

keep in mind that this is also an area that's been facing more severe drought more regularly, so the dam isn't going to be an eternally reliable source either

Severe droughts are a reason to build more dams, not to demolish them.

For the purposes of keeping water, it wouldn’t be that useful.

The Klamath is far from major population centers, and is not currently part of any long-distance water transfer. (It’s been proposed but has actually been opposed by not only the local fisheries industry but by California.)

Also I think the grandparent is talking more about power generation; there needs to be a baseline level of water to generate power, and they already don’t generate a whole lot. Holding back water also means it isn’t getting used for power generation.

To the contrary. Dams keep water from everything downstream so the recovery from a drought takes much longer.

Dams can release water downstream as needed. Without them, water would just drain out to sea/ocean in the wet season, and in the dry season would be completely gone. Without dams, American southwest literally wouldn’t exist.

Yeah the part you're missing is that the area that controls the dam often wants to keep as much water as possible during times of drought, so there's often a local power struggle... this very dam has faced similar control debates.

Without a dam, during times of drought, the downstream party does not have water either. It is the very presence of the dam that enables considerations of this sort. Without it, the water just drains to the ocean quickly, and neither upstream nor downstream gets any water during dry season.

How bad is a gas turbine? The biggest dam produced 113TWh [1]. Assuming half of that was peak load that needs to be replaced by a gas turbine running (and ignoring the other half), that will produce 35.000t CO2e per year [2].

If 1kg of salmon swims upstream how much CO2 does it sink/add to natural process? Wouldn't it not happen in another river? Or the ocean? Let's say it's 10kg (ie. 10:1). Will 3.500 t/year more of salmon swim upstream Klamath river?

There used to be a lot more salmon in rivers. There also used to be a lot more salmon in the sea. Are there a lot that don't have anywhere to go? Salmons are said to return to their birth place. I think it's fair to say no salmons alive were born in the upper Klamath river as it's been dammed for the past 70 years. Will they go there if they haven't been born there?

Climate change is also affecting salmons with NOAA at some point made a prediction there won't be more salmon runs by 2100, due to warmer streams and acidification [3].

Or did the company running the dams just saw them as uneconomical and it was happy that the state will pay part of the demolition costs to the tune of 250M$ (out of 450M total) [4]?

[1] https://en.wikipedia.org/wiki/Iron_Gate_Dam_(California)

[2] https://www.rensmart.com/Calculators/KWH-to-CO2

[3] https://en.wikipedia.org/wiki/Salmon_run#Prospects

[4]https://www.mercurynews.com/2016/04/07/klamath-river-dam-rem...

Salmon have a 4 year life-cycle, so definitely none have been born in the upper Klamath. Doesn't matter if they'll go there, they'll stock the upper Klamath with fry, and in 4 years you'll have returnees.

The company is Berkshire Hathaway by the way, and the main reason that they saw them as uneconomical is that the state has introduced legislation that they have to provide by-passes for the fish, and it would have cost more to retro-fit that to demo them.

None of these dams ever produced more than the tiniest fraction of even just the commercial value of the fisheries they destroyed. They totally didn't care.

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