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Japanese Firm Proposes Microwave-Linked Solar Plant On the Moon
littlesparkvt writes "Harnessing the sun's power is nothing new on Earth, but if a Japanese company has its way, it will build a solar strip across the 11,000 mile Lunar equator that could supply our world with clean and unlimited solar energy for generations." Some of the company's other projects look just as ambitious.
The Lunar equator is 11,000 Kilometers long.
"I do not agree with what you say, but I will defend to the death your right to say it"
Collect massive amounts of power, and beam it towards a planet. What could possibly go wrong?
In a surprise vote at the UN, the General Assembly accepted a proposal from Krasnovia to rename the planet. The new name is "Alderaan."
much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
s/Timely/oldAsFuck/. Hilarious when Huffington Post beats Slashdot to a story by two and a half months.
I am Audience.
Solar insolation on the moon is not dramatically higher than on Earth - around 1400 W/m^2 versus around 1000 W/m^2 on Earth. Granted, a Lunar solar station wouldn't be affected by weather, but Earth based receivers will suffer from efficiency loss during bad weather.
Could they achieve the same result by building a bit larger system on earth, but without the hundreds (or thousands?) of rocket launches it would take to get the materials to the moon to get the thing started?
Besides, who wants to see a big black ribbon around the moon?
A major issue is that the moon is fairly far up Earth's gravity well. It is easy to get things to low-Earth orbit and already tough to get things to even geo-stationary. The main saving of putting anything on the moon will come if you can do a large part of your construction on-site since otherwise moving that much material up is going to be tough. If you are doing automated construction on site you also are going to need to be able to make mainly a lot of solar cells. Solar cells are primarily silicon and there's already been prior research on refining the moon's regolith for silicon to manufacture electronic components and that looks possibly doable but one does need to get over some technical chemistry issues. See e.g. http://www.asi.org/adb/02/13/02/silicon-production.html.
The other issue is distance for power transmission: most designs for microwave power involve power transmission from at most a little over geo-stat at about 35,000 km. The distance to the moon is about 10 times that, so if you don't have a really tight beam, there are going to be issues. Also, since the moon change's position you are going to need a large number of sites on Earth that can receive the beam, and if you can't switch off smoothly between them always (which would itself require massive planet-wide infrastructure), you would still need power sources on Earth (possibly just massive storage facilities?) to deal with those times.
Overall, a really cool idea with a lot of technical hurdles. I hope they can make it work but I'm not optimistic.
Helps when you put the D in there.
That's what she said ... heh heh heh
Shimizu Corporation intersects with Dr. Criswell in another way that I just discovered today after searching for his more recent patents.
We've got to attract technological civilization's population away from natural ecosystems into idealized artificial environments such as Shimizu Corporation's design for what it calls the "Green Float". You can house the entire population of civilization in beach-front property on the boundary of a tropical rain forest where people can swim, fish, hunt and gather recreationally, as well as access the height of urban lifestyle. From there space habitats are likely to emerge so that the natural propensity of these "cells" to replicate endlessly needn't destroy Earth's biosphere. Interestingly, I came up with a geometry that looks very similar to that years ago, with the Solar Updraft Tower Algae Biosphere proforma and, over the subsequent years, I found a floating photobioreactor technology that requires little more than 2 layers of polyfilm that has demonstrated production per cost figures far in excess of what I projected in that proforma. Before I ran across Shimizu Corp's Green Float I had further refined the idea based on the Atmospheric Vortex Engine, which, like Shimizu's "Green Float", is ideally sited in the equatorial doldrums and could make use of the central tower of the Green Float. I posted some preliminary thoughts over at the Seastead Institute's blog.
A key problem I attempted to address in my preliminary thoughts was the early market for energy from the Atmospheric Vortex Engines that would form the nuclei for Shimizu's Green Floats. A big problem was the fact that the electric power markets are thousands of miles away from the floating AVEs even if you could build on the order of a terawatt of oceanic power transmission lines thousands of miles long. Early markets are critical for attracting capital -- the lack of which renders such grandiose ideas "non-starters".
I had thought it would be very nice to have a microwave transmission technology that could dynamically switch the power distribution to achieve the holy grail of "dispatchable" power generation for peak loads, but wasn't aware, until just now, that Dr. Criswell's recent revision of his patent serves precisely that purpose.
Seastead this.
You got your units wrong here, I'm afraid. The source you are referring to is not speaking about 1.2 MW per square km. It is speaking about 1.2 MW per km of road. Roads are pretty thin, so installing solar panels along them does not result in many square kilometers per km.
This mistake leads to your result being off by a huge amount. The solar constant is 1.361 GW per square km. Normally this is reduced by 30% by the atmosphere, but that does not apply in space. Neither are there clouds to worry about, so we can pretty much use this number directly, after dividing by pi to account for the lunar day/night cycle, giving us about 0.45 GW per square km. High-end satellite solar cells get up to 29% efficiency. Using that, we get 0.13 GW per square km. With an area of 11,000 km by 200 km = 2.2 million square km (we have already taken the night into account in our numbers), that results in a total production of 286 TW, which is 19 times the world's current total energy use. Of course, one has to get this energy down to earth somehow too. This seems to have an efficiency of about 85% (possibly squared - unclear). That partially negates the advantage of being outside the atmosphere, but we still end up receiving 206-243 TW.
So no, the main objection to this plan isn't that there wouldn't be enough energy available. It is how much resources would be spent making it. I think one will need some sort of self-replicating solar-cell-producing robot on the moon to avoid this requiring too many launches. But I have not read the tehcnical details of their plan.