Slashdot Mirror
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.
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.
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
Yes, I don't however see any data on their website about how wide they are planning to build the ring out. If their graphical renderings are accurate, they display a 195 pixel moon with a 22 pixel ring. Given that google tells me the moon's radius is 1737 km, that means the ring should be about 200 km wide.
So considering that we have a 11,000 km ring that is 200 km width, the power generation for the light-facing half should be what you'd expect from 5500km x 200km or 1,100,000 square kilometers. I've seen estimates of 1.2 mw per square km for solar. Using that as a basis we'd expect 1,320,000 mw of constant power generation. Wikipedia says to take off 10% due to conversion inefficiencies of microwave transmission of electricity and we probably should take off another 5% or so for weather and atmospheric disruptions or inefficiencies. That leaves us with 1,122,000 mw of constant power.
As a point of comparison, all the wind power in the entire world added up to 238,351 megawatts in 2011, so it is roughly five times the capacity of that. However, in 2008 the world had an average power consumption rate of 15 terawatts. 1,122,000 mw is 1.12 terawatts, so this project could supply roughly 7% of the worlds electricity if it was operational today.
The moon has an area of 37,932,000 square km though, so if we coated the entire moon and got energy from the sunny side and do the same math we get 19.34 terrawats. So, at our current state of energy usage it could power the world if we coated the moon in solar panels.
I'm not sure about the aesthetics of it though, a racing stripe on the moon.