Twice the height of the Empire State - massive solar tower for AZ • Hacker News Board

Re: Twice the height of the Empire State - massive solar tower for AZ

#21

Post by snowwindwaves » Mon, Jul 25, 2011, 3:58 AM UTC

cfgvjkljhgfb wrote: post #18

sliverstorm wrote: post #3

60%? Darn. I was hoping for better after the hype earlier in the article. Don't large steam plants approach 99%? 150,000 US Homes Is that a lot? I hate to (continue to) be a cynic, but it doesn't sound like a lot.

It claims 200MW/150,000 homes = 1.3KW for a US home !!!! So homes in Arizona don't have AC or electrical appliances and are all owned by eco-warriors

all of the appliances are not on all the time, sometimes more power is used, sometimes less. 1.3 kw per hour for every hour in the year is the average.

Re: Twice the height of the Empire State - massive solar tower for AZ

#22

Post by Eliezer » Mon, Jul 25, 2011, 3:58 AM UTC

gavinballard wrote: post #4

For any other Aussies that, like me, vaguely remember the plans for building this near Mildura but can't be bothered watching the video to find out why it didn't happen, the reason cited is a "complete lack of incentives". Sad that something like this couldn't get a dime from the Australian government while the US "welcomed them with open arms" (and, presumably, truckloads of cash).

That's not a good sign. I mean, ideally, you'd want the incentive to be, "It produces power cheaper than coal!"

Re: Twice the height of the Empire State - massive solar tower for AZ

#23

Post by knieveltech » Mon, Jul 25, 2011, 3:58 AM UTC

awarzzkktsyfj wrote: post #17

cbs wrote: post #13

Earlier quoted context omitted.

No, it's because you're splitting hairs when the message was obvious. They used 'height' not 'elevation', and it is common knowledge that the Empire State (Building) was once the tallest building in the world.

'building' is not optional.

Your burning karma thinks otherwise. Go find another hill to die on.

Re: Twice the height of the Empire State - massive solar tower for AZ

#24

Post by knowtheory » Mon, Jul 25, 2011, 3:59 AM UTC

ajkessler wrote: post #16

knowtheory wrote: post #14

Earlier quoted context omitted.

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

Re: Twice the height of the Empire State - massive solar tower for AZ

#25

Post by snowwindwaves » Mon, Jul 25, 2011, 3:59 AM UTC

ForrestN wrote: post #2

Wonderful if it works as described! That's quite a bit of power. I'd be very interested to know comparisons in terms of how long a traditional power plant takes to become profitable, and also how much initial investment this project is requiring.

750 million, payback in 11 years.

for comparison, hydro electric costs about $2 million per megawatt so a 200MW hydro plant would be $400 million, but with associated environmental concerns.

Re: Twice the height of the Empire State - massive solar tower for AZ

#26

Post by Cushman » Mon, Jul 25, 2011, 4:02 AM UTC

ajkessler wrote: post #12

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…

For what it's worth, the article doesn't claim "zero maintenance"— in fact it explicitly says "apart from a bit of turbine servicing now and then."

Now whether that's still a wildly optimistic claim is up for grabs.

Re: Twice the height of the Empire State - massive solar tower for AZ

#27

Post by snowwindwaves » Mon, Jul 25, 2011, 4:04 AM UTC

sliverstorm wrote: post #3

60%? Darn. I was hoping for better after the hype earlier in the article. Don't large steam plants approach 99%? 150,000 US Homes Is that a lot? I hate to (continue to) be a cynic, but it doesn't sound like a lot.

60% was a plant factor, meaning that the 200 MW plant output will be 200 * .6 when averaged over the course of a year, presumably because some turbines will be down for maintenance some of the time, and the temperature difference will be less at times, so it can't always put out maximum power.

And there will be transmission line outages some times too.

60% has nothing to do with the efficiency of the transfer of energy.

He says in the video coal plants run 80% plant factor, nuclear plants would be even higher, probably putting out over 90% of their rated power.

Re: Twice the height of the Empire State - massive solar tower for AZ

#28

Post by geuis » Mon, Jul 25, 2011, 4:05 AM UTC

ajkessler wrote: post #12

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…

Desert environments are extremely good at preserving things, particularly technological devices.

http://maps.google.com/maps?q=Mojave,+CA&hl=en&ll=35...

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.

Re: Twice the height of the Empire State - massive solar tower for AZ

#29

Post by kylec » Mon, Jul 25, 2011, 4:05 AM UTC

    The Arizona tower will be a staggering 800 metres or so tall - just 30 meters
    shorter than the colossal Burj Khalifa in Dubai, the world's tallest
    man-made structure.

Is there any reason why this can't be constructed to be 831 meters tall to edge out the Burj Dubai?

Re: Twice the height of the Empire State - massive solar tower for AZ

#30

Post by [deleted] » Mon, Jul 25, 2011, 4:07 AM UTC

ianterrell wrote: post #6

sliverstorm wrote: post #3

60%? Darn. I was hoping for better after the hype earlier in the article. Don't large steam plants approach 99%? 150,000 US Homes Is that a lot? I hate to (continue to) be a cynic, but it doesn't sound like a lot.

The Census says there are 110,692,000 occupied homes in the US, so 150k is 0.136% of that.[1] That means that there would need to be 738 of them to meet demand. Now, the EIA says there are about 5700 power plants currently operating in the US [2]. Continuing with the back of the envelope math, that's almost 8 times as many as would be necessary if they all produced as much as this one. Pick whatever factor you want f…

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