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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

#71

Post by Mistletoe »

ben_w wrote: post #23
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…

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…

> "will too much carbon be subducted for photosynthesis to continue?"

Great, you gave me a new fear. :)

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

#72

Post by Mistletoe »

mukundmr wrote: post #21

While 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?

Yes I’m envisioning this thing covered in barnacles. Surely they’ve thought of that?

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

#75

Post by Super_Jambo »

Tarq0n wrote: post #10
IshKebab wrote: post #3

Definitely seems more feasible than a lot of crazy energy ideas! E.g. I think this makes more sense than the air versions because you don't have problems launching/landing or when the wind stops. Probably the biggest issues I could imagine are maintenance and wildlife. They might be minor issues though. Also in most of the world (maybe not the Faroe Islands) this has to compete with solar & batteries which are gettin…

I wonder to what extent its output correlates with that of wind energy in the same region. Having a reasonably independent set of generating technologies might help with the intermittent generation of sun-based renewables.

I guess power output will basically be the derivative of this tidal height chart: https://www.tide-forecast.com/locations/Gamlagatt-Faroe-Isla...

The steeper the slope the higher the power output.

I think the real question on tidal generation is how costly is maintenance. The sea is just a very unforgiving environment. Salt water and marine life fouling everything are difficult engineering problems that just add more expense than I can imagine wind turbines having.

If they can make tidal work I guess we'll end up in a world where most of their profit comes from keeping the grid alive when it's a calm and there's no sun.

I guess this may mean these technologies aren't going to really take off until we stop using hydrocarbons to make up the shortfalls...

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

#76

Post by ksec »

jokoon wrote: post #54
ksec wrote: post #42

Too good to be true? I assume this does no harm to fish. And electricity can be easily transported back to land ( there was no mention of how this was done in the video ). Since it is portable, small, fits into a 40ft Container. And you could mass manufacture these, ship it with container. There isn't another manufacturing problem and transportation problem like wind turbine. If Yes. You could have tens of thousands…

> Surely there has to be a catch somewhere. Right? Underwater things are expensive to maintain, nothing is 100% waterproof, so rust rust rust. Underwater cables are no joke either, especially if you're building a network of sea cables. Making watertight is not cheap. And there is the question of doing high power electricity under seawater. I'm not an engineer in that field, that I think it is going to being a whole l…

Underwater cables has been done as in all the Network connection across continents. The same with high power electricity under seawater.

None of these are new. However they are all 1 to 1 build up. These new tidal kite requires many to one. And I am not quite sure how this could be done. At least cheaply.

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

#77

Post by Sammi »

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…

Minesto CEO is quoted in local Faroese news saying 800 households:

https://kvf.fo/greinar/2024/02/09/drekin-framleidir-nu-strey...

https://kvf.fo/greinar/2024/02/09/minesto-og-drekin

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

#79

Post by Sammi »

h1fra wrote: post #74

Neat, I just didn't get why they designed it this way vs a regular turbine at the floor of the ocean? if anybody knows

That has been attempted in the same location in Vestmanna in the Faroe Islands. From what I've been told it pulled itself loose immediately, and the anchoring was pretty significant. This kite swims in a figure 8, so I guess that doesn't pull as much on the anchor.

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

#80

Post by gambiting »

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!

Ok, but what do you actually use? I have a very small 3-bed house in the UK, and over the last few months we've been averaging 1100-1200kWh of electricity per month(and we heat using gas, although we do have an electric car).
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