this looks WOW worthy! Another airborne generator is Google's Makani.
Google funded this KITE style computer controlled airfoil. Its every boy's dream of an energy machine. When it worked well, they bought the rest of the company.
The simple science take is that it is only the very ends of any wind mill blade that actually produces the power - the hub of the windmill is a drag on its power production. By doing continuous, controlled loops this baby moves about a huge axis and can operate in lighter and stronger winds than conventional windmills.
I can't get the video to play at the moment, but the system that intrigued me when I first saw it was based on a simple kite design with all the technical generator bits on the ground.
The kite flies in loops alternately extending or withdrawing the tether cable. The cable drives a generator on the ground, so all of the heavy parts are land based, and the tether cable itself doesn't need to carry electricity (big technical challenge neatly side stepped).
Not needing the tether to carry power allows for much larger wings and longer cables, and the whole kite can be collapsed as it is just made of fabric like a modern stunt kite. No need for hangars to store your delicate machine in bad weather.
That's cool, and the boom deployment system reminds me of these http://en.wikipedia.org/wiki/SkySails designed for container ships to use wind simply for propulsion, like... a sail! I am loving the innovation in this space, especially with these tethered systems that can be put up and taken down with minimal ground site construction space/time/materials/expense. Hooray for high-tech versions of classic simple concepts!
C. Letellier; That is a strange demand.. Really, all it needs is a 'good' value. why insist on such extremes and say that only the 'best' is going to be worth anything?
As the video expresses, and we've seen with many of the proposed flying windpower solutions, there is steadier and far more powerful wind up at these heights, and in just countless locations. The considerable reduction in fixed infrastructure needed (mostly concrete and steel), and the ability to land these at will, whether for maintenance, for weather that would damage them, air traffic emergencies, or even to park them during dry seasons in order to avert operating costs make this technology possibly very attractive in its sheer flexibility. Add to that the ability to relocate individual or groups of these for any reasons, emergency power, seasonal migratory passage, changing weather patterns, providing boosts to weak points on the grid (??), support for temporary power needs such as construction environments or research facilities.. and this could be a terrific new direction for windpower to move towards, without the gargantuan fields of heavy equipment presently being deployed.
That doesn't mean, however, that there isn't also some good potential for using the power of big storm systems to help us, right where these weather events are also hurting us. But that is hardly their only place of usefulness. It's A point. Not THE point.
~ Bob Fiske
'Look to this day, for it is life!' -sanskrit
Location: Greybull WY north central WY zone 4 bordering on 3
posted 5 years ago
I will bet that it actually increases rather than decrease infrastructure needs if you are going to deploy them on a permanent basis as wind farms. Individual units on a temp basis you may be able to limp along without additional structure but if you are going to deploy them by the hundreds in a wind farm you will need automated hanger buildings for each to hide them from severe storms, navigation systems so the winds can't possibly tangle lines, greater lift capacity to deal with down drafts, heavy duty dopler radar for storm prediction to shelter them when needed, in ground wiring to each launch site. Also the complexity goes up because of the need for counter rotating rotors to deal with torque. By the time you get done deploying all the added things that go with this as a wind farm I am going to guess your needs greater not less. A quick google gives a 1 MW tower having a 232 ft diameter rotor. Assuming double wind speed with elevation that means power production is roughly 4 times meaning a 58 ft diameter rotor might manage in place of the other. Still a really large machine by the time you get enough lift to get that large a generator flying. And remember you will using a non renewable resource in the helium. Just like household balloons leak down over days or weeks so will your flying balloon.
posted 5 years ago
I don't agree. But then, I'm not saying these and the various flying approaches to windpower are supposed to be a silver bullet, either. I just think they have some very real advantages over the massive planted systems we are using predominantly today.
There would surely be more complexity than their test shows, with a few guys and a truck or two.. but if you look at the sheer volume of fixed materials dedicated to present-day windfarms, I think these would have a lot less than them, and the many flexibilities that fixed towers do not.
A key operational savings is the ability to bring the generator and all components right to ground as a matter of course, so that inspections and maintenance work don't require multi-skilled crews working at perilous heights with intensely expensive custom cranes and ships. The hourly costs for that work cut deeply into today's windpower's net gains. There will be a materials tradeoff, since these and almost any of the flying generating platforms will be composed of a number of materials that will likely have high wear, and so a short replacement cycle, such as the tethers, but I would suspect this could still come out way ahead of the massive undertakings involved in today's gearbox replacements, etc, on the big towers.
Many of the points you suggested are long-since solved, and really not additional complications, like left- and right-turning impellers, distribution cabling, ground structures.. they are additional to the basic flying equipment. The idea that the hangars would have to be automated, while not really even an unthinkable proposition these days, is also not likely. I don't assume these flying windfarms are supposed to be crewless.. It could be there is a basic running crew, and additional hands are called in if there are coming storms, etc.. but I don't think this has to be robots just because it's modern. I want to see this industry create some new kinds of jobs.
In any case, and not to argue too much, I also don't claim that this approach is baked in the cake (ie, perfect, wonderful and inevitable). Just that it has some real attractions, as I've mentioned. I agree that Helium would be a serious challenge.. though the more appealing designs I've liked have all been the 'tethered glider' types, not requiring lifting gases, and much easier to store low and tight in smaller structures.. and I would also hope that hydrogen could be an option as well, since it could well be generated using power from the turbines at the site, if necessary, given some water availability as well.. of course.
Location: Greybull WY north central WY zone 4 bordering on 3
posted 5 years ago
Bob. Quick question. were you at UW(Wyo) late 80's early 90's
The reason I think we need good value is the need for those resources on the ground. For example Which takes more concrete and steel? A hanger or a couple of towers? I don't know the answer. Easier service will trade off with greater wear, greater complexity, probably greater costs and certainly greater risks. My guess is that flying gear capable of real power generation will need as much or more infrastructure and its over all operating costs will be higher. I would love to be proven wrong here. Another problem here is visual pollution. What if the sky were full of such things?
And many of the problems can be solved or have been solve, that I also admit. For example if you started with a single lighter than air craft that by itself was capable of lifting say 3 winged craft. Put them all on the same tether. As the winged crafted reached winds they would begin flying enabling you to lift more craft. But for this to be safe you need reliable wind or really good prediction so you know when to reel some of the craft in. If all the winds were going the same direction say the angle was 2 to 1 for your tether. That means to reach winds at 10k feet above ground level you need 20k of tether out. So anything in basically a 4 mile radius circle around your center of deployment is at risk of the wind generating equipment falling on. Not many places in the US where this would be acceptable and they are all remote from people which is not where you need the power meaning higher transmission costs in many cases.
I do think the flying wind generation will be used. Don't get me wrong there. I just don't think land based is the best answer for it in most cases. Now in the ocean having stuff fall isn't likely to kill anyone. What if you put up the same flying tether but design it to run in hurricanes with predictable high winds all mostly going the same direction. Now your wind power potential is through the roof. Ship based so you can move with the hurricane. Now you have a sail of large potential pulling the ship so deploy a tail of submarine generators to act as the brake. Now you can tap the wind power in 2 places. Convert all the power to hydrogen and store it on the ship. The ship will likely need to be a submarine for wave protection. A storm 100 miles in diameter leaves a lot of places to deploy such things.