Japanese Firm Proposes Microwave-Linked Solar Plant On the Moon 330
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.
Re:I think I've seen this plan (Score:4, Interesting)
I think the article is mistaken, or at least very, very badly phrased. Perhaps "Earthly materials" was a mistranslation of "common materials"? Even TFA says water won't be taken to the moon for construction, instead only hydrogen which will be reacted with lunar oxygen to produce water. And if they need water for construction... well presumably they're talking full on manufacturing. The video offers no useful insights either.
Right on with the global warming bit - for (minimal) added reference I tracked down the numbers a while back, and IIRC the incremental greenhouse effect of one year's fossil fuel CO2 emissions is responsible for trapping something like millions of times as much energy as was contained in the fuel. And that's just in the first year, it will continue to do the same for many decades to come until eventually recaptured by the carbon cycle.
Re:bad bad idea (Score:4, Interesting)
It's not the energy we use that does the warming - the CO2 released from burning fossil fuels captures about a million times as much solar energy per year as there was energy in the fuel, and it does so for many decades before leaving the atmosphere.
Moon Ring Math (Score:3, Interesting)
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 [slashdot.org]. 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 [wikipedia.org] 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 [wikipedia.org], so it is roughly five times the capacity of that. However, in 2008 the world had an average power consumption rate of 15 terawatts [californiaphoton.com]. 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.
Re:11000 miles? (Score:4, Interesting)
Consider that a typical top-end solar panel can get 255 Wp [solarworld-usa.com] (Wp = Watts at Peak) for a panel. The referenced panel holds 60 156x156mm monocrystalline polysilicon cells, totaling about 1.4602m^2 , or roughly 174.6Wp/m^2
1,100,000 km^2 (from above) comes to 192 terawatts of electricity under ideal lab conditions.
Now, that's before we cut it in half (because half the moon will be in darkness), lop off 20% for losses and partially-shady cells (due to angle, not obstacles), and we get ~77.8 terawatts. Oh, and there's one more trick: heat. Heat causes inefficiencies in a solar cell, though a design with radiators on the shady side of the panel can alleviate that fairly well (they do this in space-bound solar panels all the time).
But yeah, overall under *ideal* industrial conditions, we can probably expect a WAG of about 50-60 terawatts (assuming busted cells, maintenance periods, imperfect QA during manufacture, whatever.)