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28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

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Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#61

Post by ben_w »

Y-bar wrote: post #46
ben_w wrote: post #23

Earlier quoted context omitted.

Tidal energy comes from the moon (and the sun) pulling the oceans as the Earth spins. Extracting energy from this effectively increases the drag between the ocean and the land, which slows down the rotation of the Earth. This effect even occurs without extracting tidal energy, and some of the dinosaurs (IIRC) had 19 hour days. The amount of energy in the rotation of the Earth is so huge that this basically doesn't ma…

I propose two possible solutions: A. Build some huge-ass rockets on the moon to accelerate it to offset any slowdown from changes in tidal energy. B. Divert a few billion tonnes of asteroids to crash into the moon's aft, adding both to the moon's velocity and mass. I believe that if we begin working on any of these solutions within a hundred thousand years or so from now we should be able to offset most of the projec…

You'd have to put the rockets/target the asteroid impacts on the Earth, the effect on the Moon from this interaction is to push it into a higher orbit to conserve angular momentum of the combined Earth-Moon system.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#62

Post by jvanderbot »

dsign wrote: post #58
throwbadubadu wrote: post #12

More 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…

Alien archeologists from the future: "Earthlings caused a catastrophe by trying to suck every bit of tidal energy. Via tidal acceleration[^1], they made their natural satellite fall into their planet. The curious thing is that the kind of planetary technology level they deployed to extract energy from the tides was more than enough to build huge rotating habitats, which they even knew of and called O'Neill cylinders[…

Yeah I sometimes wonder about our use of energy.

Like two whole percent goes to cracking puzzles, and if you prove you crack those puzzles we let you buy things. Those puzzles? Guessing hashes for Blockchain. Not cancer or science or engineering, just automated planet wide gambling.

Then how much is used for ads? Like top to bottom, serving ads. Must be a ton. As a planetary anthropologist, seeing how much infra we built to watch people do silly dances or say things on TikTok... Like we're so addicted to ourselves that we built all this to watch ourselves do things.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#63

Post by TotempaaltJ »

debok wrote: post #55
tetha wrote: post #14

Since 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 kettle uses ~1.5KW, a geyser ~2KW, an oven ~5KW, a stove about ~3KW. These are fairly high estimates I got from some quick googling. If you add these all up, and account for some more appliances (HVAC, fridge/freezer etc.), I think it is safe to estimate that a household less than 20KW at peak, even though it is a fairly high estimate. So going backwards from there, 1.2MW = 1200KW and 1200KW / 20KW = 60 households…

> The current national average (through Q2 2022) of homes powered by a MW of solar is 173.

https://www.seia.org/initiatives/whats-megawatt

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#64

Post by jtc331 »

debok wrote: post #55
tetha wrote: post #14

Since 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 kettle uses ~1.5KW, a geyser ~2KW, an oven ~5KW, a stove about ~3KW. These are fairly high estimates I got from some quick googling. If you add these all up, and account for some more appliances (HVAC, fridge/freezer etc.), I think it is safe to estimate that a household less than 20KW at peak, even though it is a fairly high estimate. So going backwards from there, 1.2MW = 1200KW and 1200KW / 20KW = 60 households…

If the average home was using 10kW constant it be using 240 kWh a day, which is enormously high.

In terms of average usage an average sized home in the US is much closer to 50kWh a day, so roughly 2kW average demand. That would mean 1 MW is enough for 500 homes on average. The one thing that doesn’t is peak demand load, say when everyone gets home from work and turns everything on at the same time or a particularly cold or hot day.

Edit: the average US home uses just shy of 1000 kWh a month, or just over 30 kWh a day.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#65

Post by kevinbowman »

debok wrote: post #55
tetha wrote: post #14

Since 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 kettle uses ~1.5KW, a geyser ~2KW, an oven ~5KW, a stove about ~3KW. These are fairly high estimates I got from some quick googling. If you add these all up, and account for some more appliances (HVAC, fridge/freezer etc.), I think it is safe to estimate that a household less than 20KW at peak, even though it is a fairly high estimate. So going backwards from there, 1.2MW = 1200KW and 1200KW / 20KW = 60 households…

Also relevant, houses aren't boiling a kettle and running their oven 24x7, so this is more like worst-case peak load and will be spread across different houses. Having some kind of battery storage closer to the houses will help a lot - the tidal generator can run fairly constantly and fill the battery, and the houses can draw in short bursts from the battery.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#66

Post by DrNosferatu »

The long-term projected levelized cost of the generated electricity really has to hit that $54/MWh target, otherwise the economics won't work - unless you absolutely must use some form of offshore energy production, then I guess it's an interesting niche application.

It will be interesting to see.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#67

Post by methyl »

jtc331 wrote: post #64
debok wrote: post #55

Earlier quoted context omitted.

A kettle uses ~1.5KW, a geyser ~2KW, an oven ~5KW, a stove about ~3KW. These are fairly high estimates I got from some quick googling. If you add these all up, and account for some more appliances (HVAC, fridge/freezer etc.), I think it is safe to estimate that a household less than 20KW at peak, even though it is a fairly high estimate. So going backwards from there, 1.2MW = 1200KW and 1200KW / 20KW = 60 households…

If the average home was using 10kW constant it be using 240 kWh a day, which is enormously high. In terms of average usage an average sized home in the US is much closer to 50kWh a day, so roughly 2kW average demand. That would mean 1 MW is enough for 500 homes on average. The one thing that doesn’t is peak demand load, say when everyone gets home from work and turns everything on at the same time or a particularly c…

I’m really surprised by this data. In Poland, it’s around 2000 kWh/year, which is 6kWh/day - 5 times less!

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#68

Post by Eddy_Viscosity2 »

ljf wrote: post #53
Eddy_Viscosity2 wrote: post #51

I was hoping for some sort of diagram or animation about what this thing is set up and does underwater and how this movement gets converted to electricity. Does anybody know?

Check out the embedded video in the story (link: https://www.youtube.com/watch?v=dkXinDn67Kw ) The turbine (propeller) at the back of the kite rotates and generates electricity. Since this can 'fly' at an angle to the current, the speed of the 'kite' moving through the water, will be faster than the movement of the water - therefore the turbine can be spun faster than if it were just anchored in one spot.

thank you!

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#69

Post by Symbiote »

methyl wrote: post #67
jtc331 wrote: post #64

Earlier quoted context omitted.

If the average home was using 10kW constant it be using 240 kWh a day, which is enormously high. In terms of average usage an average sized home in the US is much closer to 50kWh a day, so roughly 2kW average demand. That would mean 1 MW is enough for 500 homes on average. The one thing that doesn’t is peak demand load, say when everyone gets home from work and turns everything on at the same time or a particularly c…

I’m really surprised by this data. In Poland, it’s around 2000 kWh/year, which is 6kWh/day - 5 times less!

The USA includes many places where air conditioning uses electricity, and some places where heating uses electricity.

They also have huge and inefficient appliances, but that's probably a smaller impact on the figures.

Re: 28-ton, 1.2-megawatt tidal kite is now exporting power to the grid

#70

Post by Super_Jambo »

arethuza wrote: post #37
KaiserPro wrote: post #35

Earlier quoted context omitted.

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!

And of course some lunatics will go and find a way to have fun in them! Here's a sea kayaker at Penrhyn Mawr off Anglesey in Wales.

https://www.youtube.com/watch?v=l5o7qV1Gy04

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