Massive Energy Skyscraper Proposed On U.S.-Mexico Border | Hacker News Reader

Massive Energy Skyscraper Proposed On U.S.-Mexico Border

forbes.com

38 pointssamsolomon19 comments

EROEI will kill this thing stone dead, if the world is still thinking rationally.

Note that it is essentially a solar installation, it doesn't really say if it works during the night. But you can safely assume that if it works on temperature, the headline 'nameplate' figure of 500 gw is only available in peak conditions.

It says it uses desalinated water - which is a very energy intensive operation- so at best I figure it would be mildly energy-neutral, at worst it would actually be an energy suck. Then there is the small matter of all the embedded energy in the worlds second tallest structure. The costs are $1 billion for the tower, $100 million for the pipeline, and desal plants are about a $1b a piece these days. That's $2.1 billion invested - not including transmission lines - that's going to take a very long time to earn back.

It looks like a subsidy farming exercise to me, or possibly a stock pump'n'dump scheme.

Any time people think in terms of EROEI they get an upvote from me, as it's the problem with so many plans.

I was hoping from the headline that this was a conc. solar tower or something similar, as have been described in the past and which have a chance of being EROEI positive.

Sadly few people see the world in the eyes of basic physics and energy return on energy investment. Most of the utopians who believe we'll think ourselves out of the energy crisis without having to make any lifestyle changes or depopulate tend to rely on arguments that are almost always EROEI negative.

Wait, what...

1. massive water dependency in middle of the desert

2. dependency on pipeline through foreign territory

3. dependency on foreign border integrity

4. adjunct to military territory

...mmm, what could go wrong?

Follow up: http://www.forbes.com/sites/davidferris/2013/03/26/your-ener...

Do you seriously get surplus energy despite pumping water from 46 miles away and then 2000+ ft up in the air?

I was wondering about that too. Plus the energy required to desalinate the seawater.

http://en.wikipedia.org/wiki/Energy_tower (downdraft)

My first thought was that they were building an updraft tower.

http://en.wikipedia.org/wiki/Solar_updraft_tower

http://www.livescience.com/2644-giant-solar-tower-power-futu...

Me too. The difference is that a solar chimney makes sense, kinda. I have no idea what this downdraft tower nonsense is. Converting potential energy to kinetic? 46 miles of pumping expensive water?

Right... I've heard of the concentrated solar towers which create an updraft to drive turbines in a very tall chimney, and seen suggestions that they COULD be made to be net energy return on energy investment positive. But this one is pretty new to me. I think it's time to pop over to see what the folks on TheOilDrum.com have had to say about this - they must have seen it and are probably ripping it apart by now.

From your link: "no data on a working pilot plant have ever been collected."

I smell snake oil.

I really like the idea of solar updraft tower, where air moves the other way: http://en.wikipedia.org/wiki/Solar_updraft_tower

It's disadvantage is that it requires much more land, but it doesn't require water on the other hand. As someone noticed, the water-powered downdraft version requires pumping water from 46 miles away and then 2000+ ft up.

"Solar Wind Energy has said... that each tower would require a permanent workforce of 1,000 people." Doing what, exactly? That has to be a bogus number.

Is it wrong that the first thing I thought of was this:

http://majorslack.com/pics/screenshots/redalert_03.jpg

A Canadian company, AVE Designs, has a similar idea but with an upward moving vortex...

http://vortexengine.ca/index.shtml

something is not quite right here, does this make sense at all to anybody? even if for some reason air on the top is hotter than the air next to the hot ground, after a short while the draft itself, makes a local equilibrium, and it is hard to believe you can over come this by spraying water and cooling the bottom of the tower, and all of this just by testing on a 4 feet tall model in Maryland?!

My take was that the crucial 'energy' issue was the huge latent heat of evaporation of water that cooled the air at the top of the tower. So, the air falls in the tower partly, maybe mostly, because it is cooler and, thus, more dense, not because the air is more dense because it is wetter (is air less dense than water vapor?) but because it is more dense because it is cooler.

Then I would wonder how to recapture the water without losing a lot of energy, that is, would be fighting the huge latent heat of evaporation again? And I would wonder just why bothering to desalinate the water?

> And I would wonder just why bothering to desalinate the water?

perhaps it sucks to have salt deposits due to the evaporation?

Sure, but's got to be much cheaper to scrape off and shovel out the salt than to separate it by reverse osmosis, etc. Besides, to save on the scraping, might line the relevant areas with some tough, flexible plastic and, then, periodically shut down, remove the plastic, flex it to break off the salt, reinstall, and continue.

One word: corrosion.

I honestly don't think this idea is too far fetched, though it's going to need subsidies to get going. If it all works out, then it would be pretty revolutionary.

What a giant eye sore.

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