How on earth can such a small device generate so much energy? Wouldn't 1.2 MW of power make it very brittle just like a real kite? Or else why not scale it up and make one 100 times larger that generates 120 MW of power? Since tidal currents are much more reliable (I think) than offshore wind it almost seem to good to be true. There has to be a catch.
28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
31–40 of 192 posts
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#32Since the number 1.2MW didn't mean much to me, modern on-shore wind turbines seem to supply 3-4MW and offshore ones 8 - 12MW. But this seems a lot easier to transport and install compared to cranes and the nightmare of navigating turbine blades on trucks through places. And if these hold up to water and don't cause too many problems for wildlife, there would be a lot less discussions about these "messing up my skylin…
> In April 2022, Minesto announced a detailed plan for large-scale buildout of tidal energy arrays in the Faroe Islands. The large-scale buildout plan sets out a stepwise installation of tidal kite arrays, each with 20-40 MW installed capacity, at four verified locations.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#33More renewable is good.. but there is always one fear in my crazy mind about these: This isn't actually renewable but taking energy out of a huge reservoir (Same for solar if pea counting, but solar is really endless until the end of the solar system).. and if we'd scale it massively the result could be another catastrophe. (Same btw. with geothermal?). (Btw.. I maybe got tidal wrong, so if it is just taking energy f…
It's good that you are aware it's a crazy thought :) Nothing wrong with looking into it though. Wikipedia offers: > Movement of tides causes a loss of mechanical energy in the Earth-Moon system: this results from pumping of water through natural restrictions around coastlines and consequent viscous dissipation at the seabed and in turbulence. This loss of energy has caused the rotation of the Earth to slow in the 4.5…
> If we are being reckless and just want to use power until we figure out nuclear fusion or something better, let's say a million years or so, we can make some 180 PW from tides. But since it would almost all turn to heat, and since that is more energy than the Earth gets from the Sun, that would probably be unwise unless we find a way to get it off-planet with very high efficiency.
I think you're touching on the problem very nicely here: the problem is not "how much raw energy is there" (because there's an absolute fuckton of it) but "when does the impact of capturing this energy - thus removing it from a complex ecosystem whose stability may depend on it - and turning it into something else - thus adding to a complex ecosystem in other ways - becomes a problem", which may or may not come well before the theoretical raw energy cap.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#34More renewable is good.. but there is always one fear in my crazy mind about these: This isn't actually renewable but taking energy out of a huge reservoir (Same for solar if pea counting, but solar is really endless until the end of the solar system).. and if we'd scale it massively the result could be another catastrophe. (Same btw. with geothermal?). (Btw.. I maybe got tidal wrong, so if it is just taking energy f…
And most electricity eventually turns into heat. So there's a limit there too.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#35How on earth can such a small device generate so much energy? Wouldn't 1.2 MW of power make it very brittle just like a real kite? Or else why not scale it up and make one 100 times larger that generates 120 MW of power? Since tidal currents are much more reliable (I think) than offshore wind it almost seem to good to be true. There has to be a catch.
The speed of the tide between those islands is something like 5-6mph, and in some places much much higher (think tens of miles an hour).
Water is 800 times more dense, so moving water contains much much much more kinetic energy when its moving.
But that also means it has a lot more drag. That drag can be quadratic, meaning that you'd need to a monster fucking cable to stop it being dragged away by the tide.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#36Since the number 1.2MW didn't mean much to me, modern on-shore wind turbines seem to supply 3-4MW and offshore ones 8 - 12MW. But this seems a lot easier to transport and install compared to cranes and the nightmare of navigating turbine blades on trucks through places. And if these hold up to water and don't cause too many problems for wildlife, there would be a lot less discussions about these "messing up my skylin…
> too many problems for wildlife There were a meta-analysis regarding population of birds in areas with/without wind turbines, found no statistically significant difference (unlike coal, where difference was huge)
Yep. I mostly meant for or rather caused by this kite. I wouldn't expect it intuitively, as it's just a big object in the water, not moving erratically or obstructing anything.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#37How on earth can such a small device generate so much energy? Wouldn't 1.2 MW of power make it very brittle just like a real kite? Or else why not scale it up and make one 100 times larger that generates 120 MW of power? Since tidal currents are much more reliable (I think) than offshore wind it almost seem to good to be true. There has to be a catch.
The speed of the tide between those islands is something like 5-6mph, and in some places much much higher (think tens of miles an hour). Water is 800 times more dense, so moving water contains much much much more kinetic energy when its moving. But that also means it has a lot more drag. That drag can be quadratic, meaning that you'd need to a monster fucking cable to stop it being dragged away by the tide.
The Grey Dogs channel between the Scottish islands of Lunga and Scarba has a peak flow of about 15km/h with large standing waves - quite incredible to watch this up close and watch the sea shooting past!
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#38It’s just a matter of time before the orcas start playing spikeball with it, hopefully the team considered that.
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#39Since the number 1.2MW didn't mean much to me, modern on-shore wind turbines seem to supply 3-4MW and offshore ones 8 - 12MW. But this seems a lot easier to transport and install compared to cranes and the nightmare of navigating turbine blades on trucks through places. And if these hold up to water and don't cause too many problems for wildlife, there would be a lot less discussions about these "messing up my skylin…
A common blocker for offshore wind is people* complaining about seeing wind turbines on their formerly immaculate horizon. These don't have that problem.
*: e.g. Ted Kennedy. Rich and politically connected people like to live on the coast
Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid
#40While 28 tonnes appears to be a lot of material for generating 1.2MW of energy, it compares favourably when you look at wind turbines. How often does this need maintenance though?
> How often does this need maintenance though?
Moving parts in salt water? Frequently.
The positive thing about this design is that maintenance is potentially much easier than on an seafloor mounted turbine: if the tether is long enough, you can just make the craft surface next to a maintenance vessel with a small crane. No divers necessary, and no giant crane platforms like for offshore wind turbines, either.