Interesting Links for 27-03-2017

[andrewducker]

How class and gender make your resume less successful (tags: class gender employment OhForFucksSake ) Populism is the result of global economic failure (tags: economics politics ) "I Loved My Grandmother. But She Was a Nazi" (tags: history nazis society ) Russian police arrest anti-corruption leader Navalny, hundreds more in nationwide rallies

Comments

[danieldwilliam]

For me the interest in the Qattarra basin is the potential for pumped storage to help solar manufacture synthetic baseload.

There's a suggestion in the comments about an elevated canal / reservoir system over the ridge rather than a canal or a tunnel through it. So, during the day pump water up to the canal from the Med on one side and from the basin on the other (and perhaps between different parts of the canal system. During the night drop the water in to the basin sea with a net gain from net drop between the Med and the basin sea's water level.

If the basin sea could cope with wide "tide" levels you could scale up quite a large pumped hydro scheme there and get allt the benefits of the damper conditions.

I am unsure if the economics support doing the pumped hydro scheme as a stand alone project or whether it would depend on shipping fees from the canal and thus on the bio-engineering / terraforming of the basin.

I bet Hetromeles would have things to say about it.

(Also there is similar talk about an inland sea in Australia in Lake Eyre. Mostly talk by me. Good job I'm not an evil criminal billionaire.)

[resonant]

My personal preference would be to create a gravity-powered reverse-osmosis desalination plant.

Unfortunately, desalinating sea water is generally done at about 5 to 6 times the pressure you'd get at the bottom of a column of sea water 133 metres high.

[danieldwilliam]

I think that kind of thing turns on what one sees as the primary purpose of the scheme. Is it being done for the energy plant or is it being done in order to create a body of water with usable agricultural land around it. If the latter than it might make sense to forgo some or all of the electricy plant functionality in order to start filling the Depression with fresh water and create a lake rather than a sea.

It strikes me as an awful lot of salt to be selling. (A bit of Google and excel suggest that extracting the salt from the water would give you between 20 and 30 million tonnes of salt over a ten year period which compares with a global market for salt of 300 million tonnes a year. So actually not that much in the grand scheme of things.)

You'd also get about 500 tonnes of gold I think. And other stuff.

I wonder if there is anywhere in the world with a large enough drop that one could run reverse osmoisis just from the head pressure.

[resonant]

What about using the principles of a rail funicular?

It would likely be cheaper and faster to build an electrified rail link than a canal. When power is cheap, haul tanker cars of water to the top of the mountain. When you need power, let them roll down into the depression and extract energy via regenerative braking. Empty the tanker cars at the bottom, and send them back up empty. Unit trains can easily haul 10,000 cubic metres of water at a time, with automated filling and dumping.

[danieldwilliam]

Mmmh, interesting.

Pumped storage round tripping efficiency is about 70-80%. Regnerative braking (in a Tesla) seems to be about 64%. Not a long chalk away. Can't see anything on the round trip efficiency of rail based regenerative braking.

http://www.aresnorthamerica.com/

I guess there's no reason not to do all of it if the Sahara ends up covered in solar panels.