Really? Very cool idea, but some of the claims sound downright ridiculous.
First, the zero maintenance claim that is touted at least 3 times by the article seems suspicious. You can't really leave anything out in the desert sun and not have to maintain or replace it. Sun will disintegrate a lot of material, not to mention wind and sand. Anybody have any info or insight into what material they are using to create the "greenhouse"?
Additionally, the claim that "In fact, because you're creating a greenhouse underneath, it actually turns out to be remarkably good for growing vegetation under there." does not seem to jibe at all with the claimed temperatures ("add in the greenhouse effect and you've got a temperature under your collector somewhere around 80-90 degrees (176-194 F)"). I'm not sure I'm familiar with any vegetation that grows in near 200 degree temperatures.
Does anyone have any actual experience with this kind of tech?
The above link shows an aircraft storage facility in Mojave, California. There are a number of such facilities in the US, and many more worldwide. It was discovered some decades ago that you can leave a plane in the desert for years at a time, and when you come back to it there's very little maintenance that has to be done to make them airworthy again.
There was a story that I read a few months ago that I sadly can't find a link to at the moment. Some years back during one war or another, there was a plane that had engine problems. If I remember correctly, this was in northern Africa. The crew radioed that they were coming back to base, but they never made it. They were flying over a desert area.
A lot of years went by, and some prospectors working for an oil company were driving around the desert looking for places to drill and they came across the wreck of the plane.
The tail of the plane had broken off during the crash, but otherwise the plane was in excellent condition. There was still fuel in the tanks and the batteries were still charged. The oil guys were even able to turn on the lights and get the engines to turn over (might be wrong about that, but I think I remember that). If the tail hadn't broken, they likely could have been able to fly it out of there with not so much work.
So anyway, putting stuff in the desert isn't no maintenance, but it is low maintenance.
I do agree with your assessment about the greenhouse. Deserts are already pretty hot and plants don't grow well there. I don't think 2-3x the temp will be a big improvement.
I'm pretty sure that was part of the plot from The Mummy? :)
In any case, desert is great for preserving stuff in terms of low humidity (ie things don't rot). Not so good for preserving stuff in terms of them getting sand blasted. Especially in AZ where winds routinely hit 100mph+ during gusts and 60mph during windstorms. Not to mention the haboobs.
Also, the prototype of this tower in Spain figured out that the plastics they were using were "not durable enough". I would imagine that means they disintegrated? I'm wondering what they're planning on building this thing out of.
Seems to me like you'd need to keep all the glass clean too, which means more manpower & water/air power to get all the crap off.
I'd be quite curious what the actual maintenance costs will be. Still, no feedstock into the process means that you'd have to have pretty serious component failure to bring the running costs up to oil plants presumably.
Yes, but that brings up a good question. Anyone who owns a computer knows that air isn't pristine. It picks up all kinds of crap. If this beast has as much suction as the article implies, it's going to be inhaling all kinds of debris. I would guess it gets filtered so you don't damage the turbines, in which case somebody's going to have to be cleaning those filters pretty regularly.
That's a good point. Let me clarify. They won't have to pay for a feedstock. They may have to pay to ensure that there isn't damage to turbines, but i would have to think that turbines would be sturdy enough to cope w/ some particulate matter (or that wear and tear would be factored into maintenance costs).
What i'd also be interested in hearing is whether there's a drop in efficiency if particulate matter increases, and if so, what kind of curve fits the inefficiency
I'm trying to figure out how they would keep enough moisture in the "greenhouse." By definition there's a breeze so it's like using an air dryer on your garden - you would need to provide a lot of water to keep the plants and soil moist. That water has to come from somewhere. In addition, evaporative cooling reduces the amount of power the facility will generate and makes it heavier to lift out. Although the density of the air going through the turbines might compensate.
This will be an interesting project. Having lived in Las Vegas for a few years I can certainly see how they expect it to work. However planting grass inside the greenhouse seems a bit much.
The plant will be limited by how much heat can be put into the air inside the 'greenhouse' and overall it will be interesting to see how the feed in replacement cool air without creating dust storms and sucking up birds and what not. I don't suppose someone with Mathematica can build up the spreadsheet using the perfect gas law and the air convection to see if their claims are close. 200MW is 200 sq kilometers of surface area at a nominal solar insolation of 1KW/meter but with an efficency of 10 - 15% and an actual insolation in AZ nearer 800W/m2 that is 1.6M sq kilometers of surface area for 15% conversion rate.
I'm wondering if they have the math they did posted somewhere.
First, the zero maintenance claim that is touted at least 3 times by the article seems suspicious. You can't really leave anything out in the desert sun and not have to maintain or replace it. Sun will disintegrate a lot of material, not to mention wind and sand. Anybody have any info or insight into what material they are using to create the "greenhouse"?
Additionally, the claim that "In fact, because you're creating a greenhouse underneath, it actually turns out to be remarkably good for growing vegetation under there." does not seem to jibe at all with the claimed temperatures ("add in the greenhouse effect and you've got a temperature under your collector somewhere around 80-90 degrees (176-194 F)"). I'm not sure I'm familiar with any vegetation that grows in near 200 degree temperatures.
Does anyone have any actual experience with this kind of tech?