Comment by NotAnOtter

3 days ago

As cool as this sounds, I'm not sure I'm as enthused with stuff our oceans full of more tech, which inevitably will wear down, break, and pollute.

It's better than oil (duh), and something that provides power when solar/wind can't is great (duh). I just wish we would give up on approaches that are basically "If we had a few million of these giga-ton structures all over the ocean, they would provide power equivalent to a few dozen nuclear plants"

Lifecycle analysis is a common and increasingly detailed field which includes impacts to manufacture, transport, install, run, and clean-up installations, either cradle-to-grave, or cradle-to-cradle (includes the cost of recycling). I assume for installations like this, those studies have been done.

There's a whole tirade in "Landman" about wind turbines not being green because of this or that thing[0], ending with the statement: "in its 20-year lifespan, it won't offset the carbon footprint of making it". These are just feelings (of the fictional character, but unfortunately ones adopted by real people) that are unconcerned with the facts that, no, the lifecycle analysis shows that wind turbines break even in 1.8 to 22.5 months, with an average of 5.3 months[1].

[0]: https://www.youtube.com/watch?v=wBC_bug5DIQ

[1]: https://pubs.acs.org/doi/full/10.1021/acs.est.9b01030

  • Yes, lifecycle analysis is the holy grail.

    And I'm not qualified to say the tidal based solutions will never beat out Geo/Solar/Win + Batteries. In my informed but non-professional opinion, it seems like this avenue will never ever work at scale.

    From everything I've seen, we have the answer, we're just stuck under the boot of old money oil barons. Solar + wind + geo (depending on the geographic area) for the majority of our power generation. Nuclear + batteries to smooth out the duck curve form the bottom, paired with more aggressive demand pricing & thermal regulations to smooth it out from the top. That's the answer. But lobbyist's going to lobby.

  • Yep, lifecycle analysis is the key lens we should be using when evaluating any energy technology, especially in emotionally charged debates about what’s "green" or not

People aren't terribly keen on what happens when nuclear plants inevitably wear down, break or pollute either.

Mind you the market has tended to give up on tidal power too. The sea is a harsh environment, working there is expensive, and solar cost reductions have simply run over most of the competition. Scotland has seen quite a few innovative ocean energy companies launch a pilot, run it for a few years, then go bankrupt.

  • People are broadly misinformed. Nuclear plants release significantly less radiation than coal based plants, as an example. They do create a lot of waste that we currently don't know how to process, but the quantity is actually shockingly small in the context of a global issue. We're talking several warehouses. Not millions, not all of California. We can just pick some cave in northern Canada or central sahara and bury it there, it seriously isn't that much. It's better than where we currently store the waste which is basically the ocean & clouds.

    Meltdowns are tragic when they occur - but rare. It just gets a lot of press when a city of 50k gets deleted than when global ecosystems fail or a billion people die a decade earlier than they otherwise would due to pollution related helath issues.

    • While all that is true, the problem is specifically how much it can cost in the worst case. There's only been one Chernobyl out of about 400 reactors, and its cleanup cost amortised over all those reactors makes a surprisingly small difference to the cost of electricity, but also Chernobyl was bad enough to be considered a significant part of the collapse of the USSR.

      Likewise, although it's absolutely true we're only talking about a few football fields of even the more voluminous low-level waste (high-level is about the size of one small block of flats), this is difficult to collect when it's a layer of dust spread over a few hundred square kilometres or dissolved in the seawater.

      If one of the UK reactors had gone up like Chernobyl, the UK would have ceased to exist, not because of the radioactive kind of fallout but simply the economic fallout would have done it in.

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    • > We can just pick some cave in northern Canada or central sahara

      You make that sound easy. Finnland did it, France did it.

      But for example Germany started to look for one in 1976, failed, rebooted in 2017 and the current estimate is we might one one in 2060.

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How much will it pollute compared to other technologies? That’s the question to ask.

Thermal plants like coal and nuclear need cooling water, the output of which ends up in the sea too

Anything that stops people fishing a part of the sea is probably a good thing for the environment.

But I don't think the vision here is to fill the seas with millions of machines.

  • I like the idea of solar and support it in general, but the implementation is some places is bizarre. Instead of building solar panels over parking lots, putting them on top of buildings, or using them as covers over fields of crops sensitive to sunlight, lots of places have clear cut forests and absolutely covered mountainsides with them. The reason being that it's cheap and out of sight for most people.

    The vision now might not be to fill the sea with these turbines. But if it turns out they can be made cheaply and deployed cheaply, easily broken machines that nobody will take responsibility for will definitely be littering the oceans by the millions.

This is such a misguided concern I'm wondering if you are concern trolling...

  • How are concerns about ecological impact misplaced when discussing solutions to ecological problems. It feels pretty relevant to me.

    And from everything I've seen/heard, tidal based solutions are just fundamentally incompatible with their product. Keeping sensitive metalic moving parts in saline solution exposed to the sun for years on end - paired with other random things like boating accidents or marine life - it's a non-starter. Constructing these things creates pollution. If it's lifecycle impact is less than oil's, great, I just don't believe we'll ever get to a state where it's better than oil AND (solar/geo/wind) + Batteries.

    • Because the amount of pollution these things generate is clearly totally negligible. Metal in the sea does not matter. And they are an alternative to burning fossil fuels which is clearly far worse.

      They may not be a good commercial idea due to the maintenance cost (hence this article) but the idea that they would pollute the seas and therefore we should burn oil & gas instead completely idiotic.