An example of the problem of the space occupied by wind turbine farms:
https://www.ans.org/news/article-933/wind-nuclear-infographic/
Optimally, wind turbines should be placed at least 7-15 diameter widths apart.
Not too far from:
You can learn about basic problems of energies then give your opinion.
It only states that wind farms occupy land. It doesnât quantify the costs of that. It also isnât about offshore wind, which is I think where most development is nowadays.
My opinion is on how to compare solutions: you start with the costs associated with the current situation and compare that with your proposed solution. Itâs one of the first questions anyone should ask.
No. Please before replying take tour time to read the link I mentioned, and also read carefully what I wrote.
Yes.
The link doesnât answer my questions above. Also it is outdated.
Iâll ask you to carefully read what I wrote above. Iâm being reasonably precise I think.
This idea of yours has the benefit of it just being rearrangements of wind turbines compared to convention, so it should be more straightforward to compare the costs of doing it like this. Iâm not asking for the cost of your first proposed solution in this thread, and others like it, because there are too many unknowns for those.
Itâs a density problem. If the question of cost came naturally from density, you would have had the answer a long time ago.
Iâm using precise language. I used the words âgive figuresâ and âquantifyâ, to put the problem in numbers. A possible answer should have numbers. You could also say that you donât know or care.
If you carefully read my answers and the link I provided, which is still valid, you would have a quantified answer to the density problem.
I guess that the price per km² to pay would be lower in Antarctica than in ChicagoâŚ
I will end this discussion.
Some elements about the costs of offshore wind turbines are on Wind farm costs â Guide to an offshore wind farm.
They donât include capacity density concern which is another field.
As I mentioned (âItâs a density problemâ) the studies about arrangements offshore in this topic include the capacity densities.
For the offshore version: The ring which supports the aerofoils can be a skeletal structure, made in sections and of neutral buoyancy, mainly several metres below the water line with â conning towers / floats â above water and on which the aerofoils are mounted to ensure they are well clear of any storm / freak waves. This achieves 3 things: (1) Boat access to the generating hub. (2) Very little stress on the support structure due to waves as most is below the water. (3) The support structure and the links to the hub create a friction link to the water. The structure and the water become a giant flywheel of millions of tonnes storing multi GWh of energy. As with any battery / flywheel there are losses but Couette flow analysis indicates that this is relatively minimal.
Welcome to the forum @GuyM.
Thank for your presentation. If necessary, please correct any possible misinterpretations including mine, concerning the system as a whole and the flywheel effect.
Thank you for the welcome.
The real advantage of including the flywheel is that energy from winds above the generatorâs capacity can be stored kinetically to supplement the power from lighter winds. The more frequent the change in wind speeds the greater the advantage. The cost of a system tends to be relative to generator capacity and the cabling infrastructure. Increasing the annual production by using a flywheel in this manner reduces energy cost but more importantly lowers the lifetime CO2 emission rate per unit of power generated.
What about water friction/drag? This sounds like a broad, sweeping idea, with few details and no numbers behind it.
The losses can be found using Couette flow analysis. I gave PierreB an example which I note he has published with my consent ( 20 May ). Like any storage system there are losses but in this case it is surprisingly minimal. We tend to think of driving a boat or ship through the water rather than allowing the water itself to rotate at different rates depending on depth and position.
Hi @GuyM
I think itâs a concept worth studying.
Iâd understand better though, If the large-contained-rotary-water-mass-flywheel was in the centre and therefore had less surface area and less speed at the interface to induce friction. Also the speed of sails wants to be multiples of wind speed to be efficient e.g. it makes sense for sailed parts to be at a large diameter if you want a low rotary speed but high efficiency.
Can the sailed elements be foiled yachts tied together around a large perimeter? Can the yacht ring use radial lines (Lines tighten and change toward angled under torque loading) line inward to pull the large mass around?
Iâm probably talking nonsense though
If you make the foiling yacht ring heavy maybe that could lift to help reduce drag
I think the flywheel would loss momentum. So it would store a lesser kinetic energy due to a lower linear speed. Moreover more mass can be stocked at the periphery.
I think continual powering of a giant oceanic whirlpool would continually sap energy from the system, reducing output most of the time, and any âenergy storageâ would be fleeting and brief, mostly useful only for smoothing output, if at all.
The idea is apparently to raise output during lulls to maximize generator capacity utilization, but I think pushing all that water in a circle would instead reduce output so you would need a smaller generator because you are throwing away so much power to rotate all that water.
Not only that, but vertical-axis turbine blades typically travel at 4 times the wind speed, so, please let me understand - in a 30 MPH wind, the blades will be traveling at 120 MPH, with the high-drag underwater support structure traveling at 120 MPH underwater, dragging âmillions of tonsâ of water around in a circle at something approaching 120 MPH? Is that the idea?
Hi Doug,
And on https://www.maxwindpower.com/ :
It was found that the giant VAWT could produce 300 MW in 11 m/s winds at a tip speed ratio (TSR) as low as 2. The power curve shows over 300 MW between TSRs of 2 and 4.5 peaking at 375 MW at a TSR of 3.
That said the faster the flywheel, the more it is efficient, and the more drag it generates.
I have a question to @GuyM about how the air cushion system works and how it could avoid huge drag of the whole VAWT carousel.
OK so this vertical-axis turbine is supposed to operate at half the tip-speed ratio of a ânormalâ vertical-axis turbine? That would imply 4x the solidity of a regular vertical-axis turbine (4x as much blade in the circle) which would likely cost 4x as much, and be less efficient to boot.
One aspect of âThe Professor Crackpot Syndromeâ just occurred to me as I was out watering palm trees just now (Weâre supposed to have record heat for this date today).
Iâll use the example of âAstroâ Teller who was in charge of âGoogle-Xâ or whatever they called their experimental branch that bought Makani.
I read or watched some of his reasoning, and in my humble opinion, it sounded a bit âout-to-lunchâ. I came away unimpressed. Broad, sweeping âideasâ, supposedly so wise as to be considered âvisionaryâ, to the point where it would be up to other, less-âvisionaryâ underlings to flesh out the details. Result? Makani might be an example: Everything sounded great, until the details emerged, at which point it turned into âWell maybe this isnât going to work out as well as we thoughtâ.
The history of replacing the standard wind turbine with something else has a pretty-much 100.000% failure rate. Maybe there are a few promising tidbits here and there (which I like to think I may have demonstrated), but, overall, no completely new design paradigms have taken hold, and in fact, most have overwhelmingly failed.
There are known symptoms: âVertical-axisâ is one of them. Anyone promoting vertical-axis turbines should know this going in. Yet they are endlessly proposed and often built. There seems to be a certain personality-type involved, and I believe the root of their often-misguided thinking can be attributed to what is called âsingle-factor analysisâ. That means a single aspect of a complex and inter-related set of factors is considered to the exclusion of all the other factors, and then even ignored when that single factor becomes problematic. An example is the typical process of saying vertical-axis turbine are better âbecause they donât have to aimâ, then introducing an âimprovedâ âcycloturbineâ that DOES require aim to constantly adjust blade pitch as the blades transit their circle.
Another example might be fixating on one factor affecting global temps, such as the level of a single trace gas, without truly considering the whole picture, as the former head of the IPCC points out.
Anyway, it is interesting that people still talk about how âsmartâ and âtalentedâ the team hired for the Makani effort was supposed to be, contrasted with the results.
Now donât get me wrong: I get excited thinking about vertical-axis turbine designs too. You never know when someone could come up with a design that so maximizes the good points, that it successfully overcomes the bad points. But I will say, I donât think maximizing friction with the water to the point of creating a giant 2-mile-wide oceanic whirlpool is a sensible approach. To me it is dripping with problems, including everything from the improbable scale on the order of 0.1% of the distance across the entire ocean, to the idea that friction/drag with the water would be intentionally maximized and called âenergy storageâ⌠How about âenergy wasteageâ?
One thing about the internet: It lets everyone be an instant âAstro Tellerâ - soooooo visionary that one is never expected to actually build or demonstrate anything, just spew out such âamazingâ ideas that someone less âvisionaryâ can fill in the pesky details.
Iâd say why not build such a system at a workably smaller scale, and demonstrate whatever supposed superiority is inherent in the concept, THEN suggest it should be built a bit larger. One step at a time.
Which reminds me of another aspect of âThe syndromeâ: âWe have to build it REALLY BIG or nobody will take it seriously!â
Well, honestly, I do not take this idea seriously right now. At a minimum, Iâd be trying to minimize water drag to the maximum extent, rather than trying to spin half the ocean and calling it âenergy storageâ.
What I like about this project is the fact that it points to two key problems of wind energy: density and intermittency.
For the rest we (comprising me) should sweep in front of our door, knowing that we do not stop discussing wind systems that we know will never see the light of day. You can always blame Makani, but what are the results of the other AWES?