I would not have guessed that the solar arrays beneficial effect on precipitation is dependent on them not being too efficient and so releasing more heat than bare desert (which is very reflective). From the article - "The precipitation increase in our solar farm experiments is due to the relatively low conversion efficiency of the panels (15%, typical current conversion efficiency for photovoltaic panels), which res…
I still consider it a win even if solar panels reach 45% efficiency: surplus energy can be used to desalinate and transport seawater for irrigation, or by condensing it from air (releasing the heat of condensation)
That seems a bit excessive, considering that the world energy consumption is only about 18 terawatts (and only about 3 terawatts of that are electrical right now).
Civilisation is to a large extent constrained by available energy, which is why new energy sources have lead to industrial revolutions. As long as you're not spending other resources on it excessively any massive amount of energy surplus can be put to good, previously uneconomical and fantastical-seeming uses. Given enough energy you could regulate the entire biosphere by brute force. And if you ever want to get seri…
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
Miami can only be considered "hottest" because it never gets cold and you consider the average. It actually spends a long time near room temperature. Somewhere like Las Vegas or Phoenix gets both hotter and colder. If we arbitrarily pick 70F as room temperature, Miami has a typical annual high/low spread of approximately 60F-90F or -10 to +20 degrees relative to room temperature. Meanwhile, Minneapolis has a typical…
You should look at section 2.2 in the article. Miami has more cooling degree days (2423) per year than Phoenix (2327) or Las Vegas (1786).
Heat transfer, though, is based on temperature differentials - if Miami is +7degrees every day of the year, and Phoenix is +20degrees only 117 days per year, the energy demands of Phoenix for cooling could very easily be much higher (energy lost through walls, roof would be much higher, as would mass transfer of energy when doors open.) This is irrespective of local construction. Add to this, radiative gain (insolation through windows) is not captured in the degree-days statistic, nor is humidity related cooling (condensing water takes a lot of energy!)
Almost no one in Europe has per-capita energy use anywhere close to the US, so why would China? And I don't think it's just that we have less AC, though that's surely the strongest contributor.
For reference for anyone curious: the US has a final energy consumption of 6.0kW per capita, the EU average is about 2.9kW. (2009 data) At that point, China was at 1.3kW/citizen, Africa at half that, India on the level of Africa and the middle East slightly below the EU with 2.3kW. Wikipedia [2] uses world bank data instead which seems to measure differntly, but the relations are roughtly the same. 1: https://www.eea…
I'm confused by your wording and by wikipedia. Watts are a measure of power, not energy. kWh is a measure of energy.
I guess the votices generated by wind farms quite beneficial in a desert region. Unless you're an ectothermic creature (like a lizard, tortoise, snake, etc...) which relies on the cool of night to hunt food and find water.
Yeah, I was thinking that the cool temps at night are necessary for condensation. Without it, the plant and animal life in the region could be devastated.
If we're talking about deserts, there is next to no plant and animal life, and part of the goal of this would be to change that.
What they do not model is the local effect of the cities that will need to be built to service all these panels. 9,000,000 square KM is a gigantic area. Millions of people will be needed to maintain these farms. Those people will need to either live locally or be transported regularly. The study should model how the presence of those people in such a relatively underpopulated area will impact local climate. 1 person…
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.
> The wind and solar farms simulated in the study would cover more than 9 million square kilometers and generate, on average, about 3 terawatts and 79 terawatts of electrical power, respectively. This study is looking at a combined farm size that's almost as large as all the land mass in the US. https://en.wikipedia.org/wiki/List_of_U.S._states_and_territ...
That seems a bit excessive, considering that the world energy consumption is only about 18 terawatts (and only about 3 terawatts of that are electrical right now).
Well, the extra energy can be used for CO2 capture :)
And the win of an arable Sahara would be just incredible.
If countries like China, India, Malaysia, Nigeria etc. start to have per-capita energy use close to that of the United States, global energy consumption could easily double or triple even without any increase in population. I said "if", but I really should say "when", because this is what's expected to happen as these countries modernize and start getting things like air conditioning on the same scale as US household…
Almost no one in Europe has per-capita energy use anywhere close to the US, so why would China? And I don't think it's just that we have less AC, though that's surely the strongest contributor.
Yeah, I was thinking that the cool temps at night are necessary for condensation. Without it, the plant and animal life in the region could be devastated.
If we're talking about deserts, there is next to no plant and animal life, and part of the goal of this would be to change that.