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I did some reading about this yesterday:

* this is a record for the time a turbine has been under the sea without any maintenance, which proves its commercial viability

* because it generates powers during high/low tide, and because the lunar cycle is different to the solar cycle, it could help fill in the parts where solar falls off in a predictable way

BUT:

* Tidal energy is valuable but geographically constrained

* Only a few countries have suitable locations for it (UK, Canada, France, South Korea)

* The Global Technical Potential (in TWh/year) is 1/10th of offshore wind

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"

Anything that stops people fishing a part of the sea is probably a good thing for the environment.
Not to sound like a crazy person, but, does taking energy from tidal waves mean taking energy from the momentum of the earth itself? I read a long time ago somewhere that if we extract enough tidal energy, the earth's rotation could slow down somehow. Obviously as a layperson on this matter I'm not that well-informed but just curious of the possibilities if anyone knows.
Yes, but tides are already sucking a huge amount of rotational inertia out of the Earth all the time even if we aren't actually using it for any practical purpose. The only reason its not a problem is that the Earth has so much rotational inertia to begin with that it will take a very long time to run out.
Maybe these are the windmills that drive the whales crazy? To paraphrase wind-watch.org (sounds non-partisan)

> The obvious concern that most people might guess will be dangerous and damaging to [swimming] wildlife are the spinning blades themselves. While large white spinning [turbine] blades rotating [below] the horizon or in an advertisement seem bucolic, restive, and like the perfect green energy source, the fact is that the tips of the blades can be spinning at up to 200 miles per hour. Those speeding blades can act like a giant blender for large [fish] such as [tuna] and [whales] which fly around the commercial [water] turbines and chop those [fish] up. Biologists have found that even small species of American [fish] regularly get killed from the spinning turbines of commercial [water] turbines.

/s

Only 1 of the four turbines has been able to operate for 6 years without pulling it out the water. The other 3 have needed costly maintenance https://www.waterpowermagazine.com/news/sae-secures-loan-for...

It's a nice idea but costly compared to solar even in places like Scotland.

Imagine if we gave up making cars because we had some failures initially. Everything is costly in the beginning.
Well, they just need to use just the ones that don't require maintenance.
Out of sight, out of mind...
One thing is not immediately obvious is just how hostile that area is.

Firstly sea water is corrosive, plus if you add all the sand and other particles that are in there it becomes abrasive as well.

BUT

the tide also reaches speeds of 30kmh (18mph) twice a day.

Caution, by harvesting tidal energy you're tapping into the potential energy of the Moon, making it move closer to us at an increased speed.
Where I live there's a tidemill that's been running for 850 years.

Still provides power today.

Sounds like they need to get the quality control down pat if only 1 out of 4 of the turbines achieved this goal - still a promising milestone, though.
The real problem: if this technology is viable, it will immediately be attacked with disinformation campaigns (“but it kills dolphins!”), lobbying against it, government red tape, and tariffs.

Solar, wind, and storage can solve most of our energy needs, TODAY, but look at how it’s being treated.

We have debate around this in New Zealand

The problem here is you have a large body of water that is a huge and significant nursery for fish, and the best place for the turbine is where the water narrows.

If the turbine is a barrier to the fish, (and who knows?), then important fisheries may well collapse

This is an objection that needs to be taken seriously and investigated, so I was disappointed that the article did not address effects on marine life.

Personally I think that the turbines and marine life can co-exist, but we need facts, not reckons

Nice.

Tidal power only works where the geography is right. A bay with a choke point to the ocean, like this one, is needed.

Or the mouth of an estuary, or an underwater shelf where currents are forced up or down, or any stretch of water with sufficiently high tidal ranges etc.

There are plenty of places where water is naturally under pressure, tidal power is definitely something we should be pushing for more as a species.

I wish they provided pics of one underwater. I love stuff that invokes a feeling of submechanophobia
The ocean is brutally unforgiving, and until now the skepticism around durability has been justified. But if projects like MeyGen can show that tidal infrastructure can go the distance, it could unlock a huge untapped energy source
They're not exactly the same thing but for comparison, France has the Rance Tidal Power Station that has been producing 250MW for 45 years. South Korean made a more powerful one at 254MW. This pilot produced 4.5MW when all 3 turbines were operating normally.
See also the Scottish company Orbital Marine Energy with their really cool floating design: https://o2-x.orbitalmarine.com/

I believe they specifically designed it to simplify maintenance

Current energy sources are ~all either from solar radiation (indirectly for fossil fuels) or nuclear fission. Tidal energy is cool because it is to a rough approximation from neither of them!
> It’s very hard to take what is essentially a wind turbine normally found on land

To be pedantic, a lot of wind turbines are placed out at sea.

Aren’t we just picking up Pennys when solar and wind are available?
It will be interesting to see how the right disparages this form of non-fossil fuel based electricity generation.
What do these turbines do to Marine life? Fish, dolphins swimming next to the spinning blades. Krill, other micro marine life in the water, disrupted water currents affecting every forms of life?

Because we are not "allowed" to ask these questions, I suspect these environmental efforts are just the vehicles to make money for certain political groups. Just as "freedom on the march" is a vehicle to make money for other groups.