Hi Rod: Thanks for saving me the trouble of posting this.
Their stock has rebounded a bit, but still a fraction of its price in February.
My take:
This is just one more “press-release breakthrough”, authored by the company themselves, as a public relations exercise to maintain optimism for their investors.
If you read through the recent communications carefully, they don’t really say much, and I wouldn’t put too much faith in them. They say data will be available to customers. Customers? (They have customers?) If they have good data, why not make it public? I’ve seen this movie too many times before. I’m not buying it. I believe in the fullness of time, we’ll all see this story slowly fall apart. What would be nice to see would be a story that did not originate in the company itself. Obviously they are going to walk on eggshells and carefully play word games to make everything sound great, but personally, I don’t believe it.
It is both satisfactory and vital to see that the February installation of Dragon 12 has resulted in a three-month period of successful production testing.
I read this as they were able to perform testing for three months without the equipment breaking down. And they were able to capture data to support their business case.
I think this is nice progress report. Looks like they are making some progress. Probably still not there ready to deploy hundreds of these, but that should not have been expected so soon.
Yeah, well, “as you read” is just “as they wrote”.
Where did it say the equipment didn’t break down?
They said uninterrupted testing, not uninterrupted production.
What happened to the thousand homes they were powering?
Where are all the happy people with electricity they didn’t have before?
Where are the suddenly unemployed people who were previously powering this area?
Oh wait - tides are predictable, but still “intermittent”…
How many Kwh or MWh did they produce in 3 months?
Key information mysteriously missing…
It’s easy to just read press-release info and just accept the message as it is hopefully intended to be (mis)understood.
But what is the real story behind it?
Either we will see a lot of these happily powering a portion of our civilization, or it will fizzle out as one more press-release breakthrough.
With our background I think we know a bit better how to read between the lines in these news stories (though the news value is indeed limited). Im sure they would have liked to share the information you want, so the fact that its missing probably means they didnt get there yet.
Though as it stands, I don’t think Minesto commited to a certain date. What they are presenting does actually look like steady progress
[note when I say our background I dont intend to compare them in any way, I just mean your background and my background]
OK well, none of these “powering X hundred homes at remote location Y by date Z” stories has proven true so far.
Let’s remember the original press-releases:
They were supposed to “power 1000 homes” using an intermittent - what was it - 1.2 MW device?
If it ran at full power 100% of the time, that would be 1.2 kW per home.
Maybe if they were small houses with coal or gas for heating, cooking, etc., you could power a home with 1.2 kW continuous. No air conditioning or heating, maybe no hot water… I know my home takes a 10 kW wind turbine (which actually produces 12 kW) and I end up with extra at the end of the year, which i only recently noticed, and started heating electrically. But I would not even notice a 1.2 kW turbine - well I had a couple of them running, and did not notice any difference. but I wasn’t looking that close.
But I’m thinking this tidal turbine might have a similar capacity factor as wind turbines and solar, about 30%, because the tides are not always moving at top speed, if at all. So maybe they could produce 350 Watts per home on average? That casts doubt on their first claim of “powering 1000 homes”, as a start. But it does fit the pattern. Next, this project was not announced as just some test - it was supposed to be the real deal - a ready-for-prime-time installation to power a certain number of homes.
But then even THAT story is quickly watered-down - now it’s just “a test”, “verification”, getting “data”, “reducing uncertainty”, you know, stuff like that.
If they wanted to make good on their original claim, and pretend they were in fact powering 1000 homes, full-time, for 3 months, they could have included the only relevant data required to back up that original statement, which would have been how many MegaWatt-hours they produced in 3 months. Then even dumb kids like us could have done the simple arithmetic (maybe with the help of a teacher) to figure out if that original headline about the 1000 houses was correct. Based on their original statements, the ONLY relevant outcome was how many MWh they produced - that’s it - but they did not provide even the slightest hint as to what such a number might be, so… :0…
Big tether fairings
I have been wondering about tether drag for Minesto because the physics involved for subsea tethers is more demanding than for flying devices (forcing a very short tether). It is interesting to note they installed the fairing.
Also interesting to see they installed real 3D fairings rather than tustles. I would think the latter would be much easier to maintain and handle…
Did you mean tussles? I’m not following anyway.
Hi. I am actually not sure what the term is. I was referring to those thin strips of leather that could hang on the back of a country style leather jacket.
I have seen those being used to reduce drag on seismic streamers, a use case nearly identical to Minesto’s I suppose.
The device I am referring to is a simple one made of thick tarp, sewn as a tube into which the streamer is inserted, then having triangular tarp patches hanging after the streamer.
The device is cheap and easy to handle, eg. it could be put on a reel. A solid fairing I suppose could not do that.
I think its easy to make the design for subsea components too fine and detailed. Things grow subsea, parts need to be coarse and solid. For instance, I expect a solid fairing may grow stuck quite quickly. But these are just guessing and speculation. Time will show if Minesto’s fairings do the job or not.
I thought those were called tassels, but google says it is either that or “fringe”. Towing streamers with them:
Note the thin cables, you could wonder if that still works with thicker cables.
For under water flygen I like Minesto’s solution better:
- Likely much better hydrodynamic performance.
- Less likely to catch seaweed or to foul due to the smoother surface and the likely anti-fouling coating, and with that have a likely similar cleaning schedule as the kite. Cleaning a coated surface should also be easier and quicker than cleaning that much fabric all at once. Their business plan calls for servicing every 6 months, but it had been operating without problems for 4 months at the time of this talk so I think the speaker is implying longer time between servicing might become possible.
- Likely modular, so likely easier to make, to replace or to clean individual parts. The airfoils are never in focus in de video, but you do see dark spots at the chord line, which might indicate bolt locations to bolt the two halves together around the cable. You can imagine during servicing that makes it still possible to check the cable itself.
The airfoils do have sharp edges. If they are not aligned during operation that might be a place for seaweed to collect.
The talk has mediocre subtitles so it isn’t the easiest to follow. Some takeaways: partners are interested in hundreds of MW to GW scale farms; tidal is not correlated with other renewable energy sources, which is good; tidal has market potential particularly in Indonesia for example where other renewables are less viable than you’d think; total power delivered is important, so it’s better to focus on that at the cost of capacity factor; future work is also on developing larger kites that can also get closer to the surface and that can extract significant power from relatively slow moving water, which no other technology can. This leaves out a lot, so go watch the talk if you want to know more.