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Modeled impact of large-scale wind and solar farms in the Sahara

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Re: Modeled impact of large-scale wind and solar farms in the Sahara

#101

Post by kryogen1c »

peterashford wrote: post #78
kryogen1c wrote: post #67

Earlier quoted context omitted.

The concern is not the output of the sun, but energy moving in an unplanned (and unplannable fashion). In other words, solar panels shade ground that would have been sunned. Windmills change atmospheric differential pressure by removing windspeed. The best case scenario is these changes are negligible, but that is a luck-based result. We have no idea because global climate is not effectively modelable.

You're worried that we haven't discussed the results of something that you admit is not effectively modelable?

Yes.

Just because something is difficult to model doesn't mean the outcome/results can't be wildly dangerous. We should still try and guess the impacts of our actions, but it seems like no one is concerned.

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#102

Post by [deleted] »

peterashford wrote: post #78
kryogen1c wrote: post #67

Earlier quoted context omitted.

The concern is not the output of the sun, but energy moving in an unplanned (and unplannable fashion). In other words, solar panels shade ground that would have been sunned. Windmills change atmospheric differential pressure by removing windspeed. The best case scenario is these changes are negligible, but that is a luck-based result. We have no idea because global climate is not effectively modelable.

You're worried that we haven't discussed the results of something that you admit is not effectively modelable?

[deleted]

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#103

Post by Tade0 »

sandworm101 wrote: post #86
infogulch wrote: post #44

Earlier quoted context omitted.

This line of thought interested me so I went and looked for some numbers. The 10 sqkm 648 MW Kamuthi Power Plant [1] was built in record time in 2016 at a rate of 11 MW/day with a crew of 8500, which comes to about 2 months. This project is many orders of magnitude larger, lets be generous and say there is a 20x economy of scale in this project above Kamuthi: 100 sqkm / mo / 8500 crew. With 100 such crews (a lot) it…

1% per year? So some bits of these solar plants will last a century or more? I'd put a 20-year expectancy on everything, to cover both degredation and periodic upgrades. That is 4%+ per year. Nothing functional lasts for a century in the desert.

That figure is for the power generated only. Exposing the panels to the elements is likely to cut the life of some of them short.

But all in all it's essentially a rock generating electricity in certain circumstances. Not much to go wrong here.

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#104

Post by whatshisface »

selectodude wrote: post #79
whatshisface wrote: post #77

Earlier quoted context omitted.

> The three-car garage McMansion with double-height ceilings and a double-height foyer is a ridiculous amount of space to cool down and heat up for a single household. That's definitely not a significant contributor to American energy usage, given that not everyone in America is a millionaire.

There are 139 homes for sale in the Dallas Metroplex that have 6 or more bedrooms for $600,000 or less.

There are 1.318 million Dallas residents. 139/1.31M = 0.0001. Not too significant.

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#105

Post by DoctorOetker »

xyzzyz wrote: post #45
abecedarius wrote: post #20

Earlier quoted context omitted.

How would you go about it? Lots of high-voltage lines, or is there something else that'd make more sense for this unusual setup?

Standard 800 kV DC line from Algeria to Berlin (2400 km) would incur less than 10% transmission loss.

What's the maximum current carrying capability for this standard 800 kV DC line?

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#106

Post by DoctorOetker »

polaritron wrote: post #91
DoctorOetker wrote: post #82

Earlier quoted context omitted.

I totally agree with you, but if any of the many variations of space elevator becomes possible, you can balance the energy and momentum of mass moving up, by mass going down perhaps returning tourism or valuable materials mined off earth

Which is also awesome, but not an argument against installing massive, terawatt capacity photovoltaic solar arrays across a desert.

did it occur to you ... perhaps I wasn't arguing against terawatt capacity PV solar arrays across desert? ;)

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#107

Post by delecti »

lostlogin wrote: post #94
delecti wrote: post #54

Earlier quoted context omitted.

One really good example would be water desalination. I'm sure the neighbors of the Sahara could use a glut of fresh water.

A great use for the power, but also another destabilising thing for them and all the interested foreign powers to fight over.

Unfortunately I think you're probably right. It's really a shame how many otherwise great things we miss out on because people suck. Constant "this is why we can't have nice things."

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#108

Post by tim333 »

DoctorOetker wrote: post #105
xyzzyz wrote: post #45

Earlier quoted context omitted.

Standard 800 kV DC line from Algeria to Berlin (2400 km) would incur less than 10% transmission loss.

What's the maximum current carrying capability for this standard 800 kV DC line?

Not sure for a standard line but the record is "1100 kV voltage, a 3,000 km (1,900 mi) length and 12 GW of power". So presumably 11,000 amps or so for that one. I guess you can have as much current as you want by making the cable thicker.

Being built in China here approx https://www.google.co.uk/maps/dir/Guquan,+Putuo,+Zhoushan,+C...

It's quite an impressive looking thing (vid) https://www.youtube.com/watch?v=VZ2KfrP_R3s

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#109

Post by bobthepanda »

whatshisface wrote: post #104
selectodude wrote: post #79

Earlier quoted context omitted.

There are 139 homes for sale in the Dallas Metroplex that have 6 or more bedrooms for $600,000 or less.

There are 1.318 million Dallas residents. 139/1.31M = 0.0001. Not too significant.

That's not that amazing of a metric. For starters, households are what track to a house, not residents. Then you also have to consider what proportion of that population is looking to buy a house at any given time; most people tend to stay in a purchased home for a long time, so they may already live in a McMansion style house.

Re: Modeled impact of large-scale wind and solar farms in the Sahara

#110

Post by DoctorOetker »

tim333 wrote: post #108
DoctorOetker wrote: post #105

Earlier quoted context omitted.

What's the maximum current carrying capability for this standard 800 kV DC line?

Not sure for a standard line but the record is "1100 kV voltage, a 3,000 km (1,900 mi) length and 12 GW of power". So presumably 11,000 amps or so for that one. I guess you can have as much current as you want by making the cable thicker. Being built in China here approx https://www.google.co.uk/maps/dir/Guquan,+Putuo,+Zhoushan,+C... It's quite an impressive looking thing (vid) https://www.youtube.com/watch?v=VZ2KfrP…

so transporting 1 TW would be a hundred of those in parallel
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