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I am far from an engineer so I have questions. First, is the 3700ft terminus the only way for water to flow? Are tunnels not an option? $150B one time cost is a
by _8j50 4y ago
I am far from an engineer so I have questions. First, is the 3700ft terminus the only way for water to flow? Are tunnels not an option? $150B one time cost is acceptable, the interstate highway cost trillions.
My recurring idea to build next and in parallel or under major interstate highways a water way,sewage route and a high speed railway. The availabiliy of water wherever there is a an interstate highway and railway would solve so many problems including housing and it will be an economic boom. Much more land would be habitable and towns would explode. The economic activity generated will offset the costs in a few decades and this can be all powered by a combination of nuclear (water source), hydro (transmission/route/boosting) and wind+solar (anywhere?).
Actually, my idea was to use nuclear power by the pacific coast, desalinate it, deposit the brine in the desert and send the water to reservoir lakes from which my proposed interstate transportation and utility route will be fed. This will then unsher a new era of the megapolis!
Of course I will need become your leader then, naturally! (Jk).
Can someone more sane tell me how crazy this idea is and why it would cost more than the IHS? You can bond out most of the financing because the profit from rail travel, excess power and water would pay of long term bond interests, you wouldn't need to print new money or anything.
- eesmith 4y ago> Are tunnels not an option? The 3,700 ft terminus refers to the surface elevation of Lake Powell ("Lake Power" in the article) when full. A tunnel 2,000 ft below ground doesn't do any good if you need surface water. Plants don't grow well in tunnels.
- _8j50 4y agoWould the tunnel into lake powell 2000ft below not fill it up still? Is it not possible to fill a half full bucket with a hose at the bottom of the bucket? With storm drainage tunnels , they still fill up the bigger tunnels and reservoirs even though the tunnel terminates under water. What physics thingy am I missing?
- pzone 4y agoImagine a hose in the bottom of a bucket, but the opening to the hose is lowered below the bucket. The flow would go in the wrong direction. So without the elevation step, this project would drain the lake.
- eesmith 4y agoThe physics thingy you're missing is "potential energy." To raise a mass m a height h given the gravity g you need mgh energy. The minimum energy needed to raise 1 kg 1000 meters given gravity of 10 m/s/s gravity = 10,000 Joules. It doesn't matter if you raise the water to the top to pour it in at the surface, or send pressurized water out of vents at the bottom of the lake. With the latter, sure, you're putting the water lower down, but that water is pushing other water up and out of the way, so the end result is the same - if you add more water, the water level goes up.
- ncmncm 4y agoNukes are extremely expensive, and take many years to build. If you are desalinating, you have absolutely no need to run it when the sun is not out. So, use cheap solar. You don't even need photovoltaics; greenhouses suffice. You just need to move the water vapor to someplace cooler to condense out. Pumping sea water to spread out in a coastal desert to evaporate, so the water vapor is blown up to the mountains and fills reservoirs, would be much cheaper than pumping fresh water up, and would provide hydro power besides. You might need to bulldoze up the salt once a year.
- Gibbon1 4y agoI back of enveloped how much solar you'd need to replace water in the California Aqueduct with desalinated. Takes about 4000 kwh an acre foot. Aqueduct delivers around 3 million acre feet a year. About 1.2 X 10^13 Watt-hours. If you assume 5.5 hours of sunlight a day, 365 days a year. You get ~6 GW of solar. That's a doable number.
- ncmncm 4y agoI wonder how that compares to using a big dehumidifier on humid air. 3M acre-ft = 3.7e12 L. At 2L/kWh, that would seem to take >200 GW 24/7. Kind of makes sense... Who would bother with desalination if a dehumidifier would suffice? Is 4000 L/kWh for desalination right? Online I find 285 L/kWh for RO, yielding... 6 GW!
- Gibbon1 4y agoAn acre-foot is 1.233X10^6 liters. So 1.233X10^6 liters/acre-foot divided by 285 L/kWh is 4326 kWh/acre-foot. Checks out.
- ncmncm 4y agoWhile building out the 6 GW, every increment on the way would be incrementally more useful. Start with a 100 MW array and desalinate with that, and just keep adding to it until you are desalinating "enough". I think California announced that shading existing canals with solar, besides cutting millions of gallons of evaporation, would generate 12 GW. But investors really, really want to put all the panels out in deserts.