I’ve never understood why we do not see better utilization of the space under windfarms for agriculture, cattle grazing, solar panels, etc. I mean, hey, there is a lot of unused space - why not use it for something, as long as it has a low profile so as to not block the wind? Also, if you ever check out the greening of the planet from what is actually the greenest source of energy - hydrocarbons - there is a huge amount of vegetation area being added to the planet each year. Also, just as commercial greenhouses routinely add CO2 to their interior air, to enhance plant growth, food crops grow more productively in a higher CO2 environment, reducing the amount of farmland required to feed the world’s population and livestock.
In my opinion the solution to the problem of the huge space used, is to maximize the frontal area of wind swept, going towards large AWES like the one envisaged on Advanced Kite Networks.
We can easily see that secondary use is quite possible between wind turbines. In contrast, with AWES, the space between unities is occupied by tethers running fast and at low elevation angle, with a significant risk of crash because of a supposed permanent use combined to aerobatic figures, and pulling strong, all that for more efficient crosswind AWES, finally leading to a serious difficulty for another use; or at high elevation angle with less efficient static AWES, and still more tethers, although moving slowly, with the wind, a secondary use being perhaps easier but not so much.
My view is that an AWES farm should produce significantly more energy than conventional wind turbines for the same density per km², to compensate for secondary land use difficulties, not to mention other issues such like reliability.
And also the higher the wind in altitude, the more powerful the wind, but also the lower the yield becomes when exploiting it.
Well only if you say AWE must compete one to one on every installation.
That would be the best of course. And it could be an option as AWE could have access to more fresh wind due to higher altitude. But what Ive seen so far, AWE would also produce less power for the same swept area, making our job harder.
But my main point is really; are we talking about one to one replacement only [replacing VAWT with AWE on the same site]? Or, will AWE enable production at new sites also? In the latter case, you are not really competing, the question is rather if that single installation makes sense for AWE
I agree with Tallak here. Before worrying about space use and competing with wndfarms, demonstrate a single AWE system that is a reliable, economical energy solution for any use, at any time, any place. That would be a start. So far we have not seen it.
Meanwhile, I have been SCRATCHING MY HEAD FOR DECADES about WHY WHY WHY do we see windfarms in SUNNY Southern California, with ALL THAT LAND between the wind turbines, WITH NO SOLAR PANELS installed below the wind turbines, even though the land is available, sunny, and the interconnection is already there?
(Unlike Dabiri’s idea for small, vertical-axis turbines below windfarms, solar panels would be less likely to slow the wind for the regular turbines.)
Could it be that shadows from the wind turbines could damage solar panels?
And we won’t see it until the power to space use ratio is taken into account, until AWES are reliable enough, because space use and reliability are two sides of the same coin, at least until some point. Indeed even if the reliability is solved, it will not be high enough (equivalent to that of regular wind turbines) to prevent the requirement of a higher space use than that of regular wind turbines for an equivalent power.
Otherwise there are AWES that work: Kiwee, SkySails, Kitepower, Kitekraft.
Hello Pierre:
You’ve been hammering away at the space-use theme for years now.
It’s like the proverbial “rearranging the deck chairs on the Titanic”.
As I have tried to hammer home for years, there are “a million ways” to make SOME power from the wind, at SOME cost.
The fact that you can name projects that “work” is nearly meaningless. Makani “worked”, it just didn’t work well enough to ever be connected to the grid, despite seemingly unlimited funding and years of empty promises.
You could just as easily cite any of the oscillating poles, flapping ribbons, etc. demonstrated to produce milliWatts of power for thousands of dollars - but why? What do they have to do with ANYTHING?
Yes, eventually space use would be a main issue.
But that is a few steps ahead of where AWE is now.
As it is now, AWE needs a single proven, reliable use case, that makes economic sense, or at least shows the promise to make sense.
Meanwhile, I’m still dumbfounded that nobody is installing solar panels below windfarms. All that space, with the interconnection and substations already in place! Makes a lot more sense than Dabiri’s misguided vertical-axis scheme, or “dynamic soaring” schemes to affect turbine wakes.
Hello Pierre:
I’m talking about most windfarms, which have no crops OR solar panels between the turbines. In that case, which is the norm, the “choice” is add solar, or add nothing. Unless you want to be the next vertical-axis failure.
The example I used is the desert areas of Southern California, often at higher elevations (more sun) with an extremely good solar resource, and a built-in grid connection (substation). The winds usually get blowing around noon, so solar panels could add power all morning, or on calm days, without even any additional grid-connection capacity. Extra capacity can also be added to the existing grid connection if needed.
Here in the high desert of Southern California, we have both solar farms and windfarms. Nobody has ever mentioned or explained why they are not using the same land. Apparently, people don’t care that ,much about optimizing space. (?)
OK I have an idea for you then. Why don’t you buy a Kiwee system, and go have a meeting with a major windfarm developer, and explain how your temporary, miniature demo unit will power the grid. Don’t mention how awkward it will be to use, how quickly the gearing will wear out, and especially how little power it makes. Seems like you are just stuck repeating the same limited themes. The fact that some wind energy device “works” is only a potential first indicator of viability. I like Kiwee, but it is limited in its applications. More for fun than anything else. Most campsites will not have much wind anyway. most will be in the woods. That;s good, so you don’t wear out your Kiwee.
You can go find many wind energy devices capable of “lighting an LED”, or even “charging a phone”. Nothing wrong with that, but to play in the big leagues, to make a profit by supplying large amounts of power to the grid for 20 years of a power purchase agreement, you need a system that is self-deploying, powerful, economical, and that will last longer than a few days of demo-use before wearing out.
More to address your point, show how a larger version of Kiwee, or SkySails, Kitepower, Kitekraft would be a better choice for a “distributed wind” system powering a farm, ranch, small town, island, etc., than a regular wind turbine and/or solar.
Of course, that doesn’t address your windfarm space optimization theme, but it does seem that having a system that is even worth bothering to run at all, in any location, for any reason, is a first step.
Meanwhile, why doesn’t anyone install solar panels in windfarms? Maybe all the “really smart” people are so busy chasing after ridiculous, unworkable ideas, that simple, workable ideas are just too “simple” for them to bother with! For example. with your supposed concern over windfarm space utilization, when I mention adding solar, which might double production and expand the times when any electricity is being produced, you don’t seem to really care about space utilization. You only seem to care when discussing unlikely, unfinished ideas. Goofy ideas that would crash into or get tangled with wind turbine blades! This is the “Professor Crackpot Syndrome” at work. Forget simple things that work - let’s spend all day, every day, talking about nonsensical, half-baked ideas that are unlikely to ever bear fruit!
The inhabitants are concentrated in the large metropolises. And as you say, there are deserts, so there is a lot of space.
In Europe or other places in the United States, there is no desert, and the land between wind turbines is cultivated. So it is solar panels or farming.
No more than flying wind turbines.
All this is true, and to be economical, an AWES must have a correct power to space use ratio. If only one of the conditions you list and I complete is not met, it is not viable.
I add that it is illusory to think that an AWES could do without the need to maximize its space because there are deserts. Or only do AWES for deserts. But if this prevents tourism in larger areas occupied by AWES, then conventional wind turbines will be preferred.
I would point out that, as often noted by others, there are many many possible use cases for AWE systems where no windfarms are involved, so no windfarm space issues apply. As important as space optimization in windfarms is, AWE systems could find a use outside of windfarms, and outside of crowded areas where space is at a premium. I’m just pointing out, if someone CAN develop and AWE system that could work at a farm, from a boat, offshore, on a mountain, on an island, in the desert, or other open space, then at least it is a valid use case, as a start. After that, maybe it’s time to concentrate on space optimization for windfarms. Sure, it would be great to have a flying windfarm, but a single flying turbine or other AWE system could at least form a valid use-case and pave the way for further development.
When I opened this topic, I did not imagine that it would have been so difficult to master the control of an AWES over a significant period of time, as well as its energy efficiency and its ability to operate in all kinds of winds unless to be recovered, all fully automated.
Pierre: As a counterpoint to my previous assertions, what you are talking about could be a dedicated, large scale configuration aimed toward the specific problem you have been citing.
The power to space use ratio is an issue at all scales of AWE.
This issue is aggravated by the combination of the tether length and the changes of wind directions.
Indeed for a regular wind turbine, the rotor plan is vertical and wind changes only lead to pivot around a vertical axis without taking an additional space. While for an AWES wind changes lead to a displacement of the space use, leading to a requirement of a far higher space use.
At equal power and cost, and assuming that the AWES works well (which is the case with Kiwee for example), a classic wind turbine will therefore be preferred.
An AWES could, however, get away with it if the power is much higher than that of a wind turbine, which requires thinking in the multi MW range; or if the material cost (to be considered over the lifespan, taking into account replacements) is significantly lower than that of a wind turbine.
