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'World’s most powerful' tidal turbine sets sail from Dundee
- KuiN 6y agoScotland is aiming to be a world leader in tidal energy [0]. Which I guess makes sense given we're practically surrounded by pretty rough seas. Shetland has just had a tidal energy electric car charger installed [1]. Bit of a gimmick but the Scottish government is serious about making this a significant source of energy. [0] https://www.gov.scot/policies/renewable-and-low-carbon-energy/marine-energy/ https://www.gov.scot/policies/renewable-and-low-carbon-energ... [1] https://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-56482777 https://www.bbc.co.uk/news/uk-scotland-north-east-orkney-she...
- siquick 6y agoHopefully the region can start developing more long term industry like this as once the oil is over, the north east of Scotland is going to really struggle.
- jules-jules 6y agoIt already is. But otherwise I agree.
- TheManInThePub 6y ago> Scotland is aiming to be a world leader in tidal energy. Which I guess makes sense given we're practically surrounded by pretty rough seas. Rough seas damaging your tidal energy kit are the one thing you don't want. I have mentioned above that offshore wind has emerged the clear winner with respect to offshore renewable energy. Putting moving parts in salt water is always a tough prospect, and wave/tidal simply cannot scale to the extent wind can. I hate to say it, but I suggest many of the experimental wave/tidal schemes under trial are simply for green bragging rights and/or to grab funding for green energy projects...... Funding put forward by well meaning bodies that that would be better directed to other renewable energy sources. EDIT: This is Hacker News, not Reddit. If you disagree with the above please explain why in comments rather than down voting.
- arethuza 6y agoI'm not sure that latter point is actually true: "Downvoting for disagreement has always been ok" https://news.ycombinator.com/item?id=17996858 https://news.ycombinator.com/item?id=17996858
- seg_lol 6y agoI would tilt at windmills, tilting at tidal power is a waste as the projects always sink.
- Qwertious 6y agoBa dum tsssh.
- jacquesm 6y agoThat bar is embarrassingly low. Because nobody really has working tidal energy power at scale.
- wolverine876 6y agoThe same could have been said of wind and solar years ago. The same is said of any innovation. Aren't we on HN?
- jacquesm 6y agoNo, the same could not have been said. Solar and wind have been working for ages in many ways and forms. Tidal has been a pipe dream since the beginning of the previous century. It won't work. Windmills are in use the world over, the power of the sun is what causes the wind in the first place and besides has been used directly using lenses since forever. Getting usable power out of tidal energy is stupendously hard and won't scale. And yes, we're on HN. And yes, having built a windmill (not a toy, one that can power a house) and having worked with innovative solar plants (specifically: concentrators) and finally, having consulted on tidal energy projects I actually think I know what I'm talking about. Tidal energy = uBeam = Theranos.
- wolverine876 6y agoSolar and wind were widely said to be too expensive (and too limited in other ways) to compete, and I'm pretty sure that was in the last 20 years. Fusion hasn't worked out either; I'm not expecting much; I'm glad the research continues. Is fusion also a boondoggle and pipe dream?
- jacquesm 6y agoThe propaganda from the nuclear lobby was never to be believed. Solar has been in widespread use for more than 30 years, wind for millennia. Fusion will work long before we will have tidal energy plants worth writing about.
- TheManInThePub 6y agoI've worked in the UK offshore power industry. Wave and tidal energy schemes have failed to deliver useful and reliable energy after over 50 years of investigation and research funding. Putting moving parts in salt water off the UK coast is always a tough prospect. By contrast, UK offshore wind power is delivering energy cheaper than ever and has emerged as a clear winner. Given the above, I'm honestly puzzled why offshore tidal energy projects are continuing to attract major funding. Incidentally, the argument that the tide is more reliable as it always flows twice a day is a rather moot point, as like wind, the tide doesn't always flow when you want it to.
- nicoburns 6y ago> By contrast, UK offshore wind power is delivering energy cheaper than ever and has emerged as a clear winner. > Given the above, I'm honestly puzzled why offshore tidal energy projects are continuing to attract major funding. Having a diversity of energy sources seems sensible...
- TheManInThePub 6y agoThat is why we have a diversity of wind farms! Wind turbines scale much more easily than wave/tidal, both the size of the turbines themselves (much larger than a wave/tidal system could ever be) and where they can be located around the UK coast. A diversity of renewable energy sources is sensible (nuclear, wind, biofuel etc), but wave and tidal are difficult to scale and have failed to deliver.
- Quarrelsome 6y agodoesn't mean they will always fail to deliver.
- Guthur 6y agoI think that unless you drastically change the parameters of the implementation then yes it does mean it will always fail.
- yosito 6y agoDoes anyone have a link to an explanation of exactly how this turbine works? I'm particularly interested to know whether it's bi-directional, how power is transmitted back to shore, and how it's anchored in place.
- harry-wood 6y agoyes I'd like to know more details. This video shows a bit more: https://www.youtube.com/watch?v=9hN3dBpPu8Q https://www.youtube.com/watch?v=9hN3dBpPu8Q Bi-drectional? Looks like those adjusting flaps are to make it bi-directional yes, but maybe the angled legs mean it has a preferred flow direction (I'm guessing). How power is transmitted back to shore? The video seems to show, in red, some good old "big fat cable" technology. It's described only as powering the Orkney Islands. I wonder if surplus energy there can be fed back to the mainland grid. How it's anchored in place? Two massive mooring cables front and back. The main central cylinder floats, with the legs and rotors dipping down into the water (Maybe obvious, but not to me at first)
- yosito 6y agoThanks! This video was exactly what I was looking for.
- papercrane 6y agoI can't find a lot of detail, but to answer a couple of your questions. > how power is transmitted back to shore, Article says there is a static sea-bed cable that that is connected via a "dynamic" cable to the turbine. > how it's anchored in place. > whether it's bi-directional Very high level overview of the platform here: https://orbitalmarine.com/o2/ https://orbitalmarine.com/o2/ It shows an forward and aft mooring points, so my assumption would be is that at anchors are put in the ocean bed and that the whole structure is held in place by cables. It also shows a "Two-bladed pitching hub allows bidirectional operation", so I take that to mean the blades are rotated in the hub depending on which way the tide is flowing.
- lmilcin 6y agoWhat about having huge floating object with huge amount of extra buoyancy chained to the bottom? As the tide tries to lift the object the force could be converted for various purposes. This can be used basically anywhere where there are significant tides and where bottom can be reached easily. It is the same as other gravity storage methods except uses buoyancy.
- TheManInThePub 6y agoI have a report from a first year undergraduate on my shelf that suggested this.... A simple calculation shows you need an enormous volume float to generate a useful amount of power. A tidal range of a few meters isn't that much potential energy applied to a float of limited volume: by contrast, there is much greater mass of water in the sea to generate energy from.
- deleted 6y ago[deleted]
- lmilcin 6y agoOkay, some calculations. An object displacing 250kt of water (ie. size of Ever Given) has a potential of about 0.7MWh per 1m. Most coastal regions see tides above 2m and a lot much higher than that. I say 1MWh extracted daily from from a dumb metal object the size of Ever Given (and potentially much more if you are in are with exceptional tides)? I guess it would depend on how efficiently it can be built and the cost of additional infrastructure (though it would be less if you build it in form of a farm). Remember, it can be used as energy storage, so if you have a large farm you can program it to automatically pull some of the containers deeper to provide power when at low tide. Also efficiency of this can increase with the size of the tank as the amount of materials scales less than linearly. I used Ever Given as an example, but this has been built to be seaworthy and pass Suez Canal. If you don't need to make it seaworthy and don't need to make it to pass through anything and can make it any shape you want you could probably design much larger structure.
- TheManInThePub 6y ago
- seastonATccs 6y agoThe pictures looked like a real life Total Annihilation.
- aliswe 6y agoI thought it looked like a sci-fi "speeder" of some sort. Podracer.
- 4ad 6y ago> It will be anchored close to Orkney where it will produce enough electricity to power 2,000 homes. I can't possibly express my existential torment that I feel when I read statements like this in an article. Just state the damn power in SI units. A close second is measuring the size of something in terms of "football fields" or "Rhode Island" (wtf??). I am pretty sure this is tied into the general innumeracy of the population.
- jakubp 6y agoSame here. Lack of Watt output and expected (measured?) kWh cost in the lead of the story is baffling.
- davisoneee 6y agoI'm an electrical engineer and an academic. A key part of communication is _knowing your audience_, and communicating what is appropriate for them. Your average reader doesn't need to know how many W this generates. While, yes, HN may appreciate knowing the expected power output, that's basically irrelevant for the average reader. This is from the BBC, not a scientific journal. While your average reader may know that their microwave is 800W, telling them "This turbine will generate <x> kW" doesn't mean anything. They _do_ have a home. If they don't _need_ to know/use Watts on a day to day basis, then the number is just going to be forgotten. However, they _might_ remember "a tidal turbine that can power thousands of homes". It would be lovely if everyone was scientifically literate, but people have other shit going on in their lives. On a pragmatic level, I'd rather society remember the abstract idea of 'how many homes' than _forget_ the precise '<x> megawatts'.
- loonster 6y agoJust define the value in home equivalents after the actual power amount.
- JumpCrisscross 6y agoAs an American reader, home equivalents speaks to the political impact of the project better than wattage. The latter requires the context of the average home's usage in the relevant geography to contextualise.
- everyone 6y agoWow.. Kinda looks like a repurposed submarine
- GiffertonThe3rd 6y agoDoes anyone else, of a certain age, get a distinct 'Thunderbirds' vibe from this?
- ggm 6y agoYes, what's missing is the trapped maintenance crew living in a pond underwater for no reason explained in the plot, and a secret plan to take over the device involving giant sharks
- bb123 6y agoIt is almost difficult to describe someone who hasn’t seen it how powerful tides in the UK can be. Where I live the tidal range is over 12m from low to high tide and flows like a massive fast-moving river at peak times. It can easily overpower small boats and drag them out to sea. The amount of energy moving through the waterway is staggering.
- Mvandenbergh 6y agoVery cool. One of the challenges about building an energy system with lots of variable inputs is that you can't just look at the lowest levelised cost and build only that, otherwise you'd just build wind and be done with it. Adding sources that are not correlated with wind makes the overall grid management problem easier, even if those sources are more expensive the system cost may decrease. Obviously tide, while very predictable, is not dispatchable so not quite as valuable for grid management, but still shouldn't be written off just because it costs a lot per MWh. One thing that does make it hard is that peak water flow only happens in the middle of a six hour tidal cycle. For every location you have a predictable 6 hourly cyclical power curve. There's about 75 minutes between the high tide times in the North of Scotland and Southern England so on a GB grid basis, you can spread the curve out somewhat but still have that cyclical element.
- kitd 6y agoPresumably East/West gives you better differential. IIRC there's 20 minutes difference between high-tide time of the east end of the Solent and the west end. Merging the output from eg West Wales and East Anglia would give you a pretty constant supply.
- jl6 6y agoWhy does this have to float on the water? Wouldn’t it help avoid some of the more extreme dynamic forces by anchoring it just under the water level?
- usefulcat 6y agoLike pretty much any mechanical devices that lives submerged in salt water, I would imagine it's going to require some significant maintenance at some point.
- m0llusk 6y agoIt seems strange that the fan blades are not protected in any way. Isn't this likely to batter marine life and capture floating fish nets? In contrast seafaring impellers are usually ensconced in a large housing that protects the blades and directs flow.
- hinkley 6y agoMy brain keeps trying to turn that into an airplane. On satellite maps that’s going to look like someone ditched an A-10 at sea.
- GnarfGnarf 6y agoI live near the Bay of Fundy (40 ft. tides, highest in the World). We can't make tidal power work because our ice sinks and smashes the turbines. Why? The ice forms on the shore and encases pieces of rock. Huge chunks of ice drift into the Bay carrying the stone nuggets. The chunks erode and shed buoyant ice until the density is > 1, then they sink and the strong current leads them into the blades. Neither is it cost-effective for engineering companies to develop technology for our geography, the conditions are too unique and the inventions don't scale. Pity.
- pvorb 6y agoDoes anyone know why it uses only 2 rather than 3 rotary wings like on wind turbines?