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Lunar Power
An Anonymous Coward cites this article on ABC News, excerpting: "...the world would have access to a limitless power supply. The moon receives 13,000 terrawatts of power from the sun. Harnessing 1 percent of that energy, he calculates, could replace all fossil fuel power plants on Earth."
It currently costs $10,000 to get 1 lb of material into orbit. How much would it take to get it to the moon? One hell of a lot.
It's going to be a heck of a lot cheaper to burn money to make power than use the moon for a long, long time.
Yeah, except for that Ozone Layer, which has that whole 'filtering' ultraviolet light part, whereas the moon has no atmosphere.
Apparently this dude has never put a marshmallow in his microwave oven.
--All your stolen base are belong to Rickey Henderson
The height of delusional techno-fantasy-masturbation. Come on people, let's think here. What's easier... Getting photovoltaic or thermal concentration arrays up into orbit at the cost of thousands of dollars per ounce and then shipping them to the moon, installing them, and somehow shipping back gigawatts of electricity to earth by radiation..
OR,
putting up photovoltaic or thermal concentration arrays on earth. On your house, your car, in the backyard, on fields, on buildings, on deserts, on woodlands, on fences, on anything that's flat, vertical, or in between, using unskilled labor and unsophisticated tools.
The answer, of course, is to use less energy period. But you can't strap a nuclear warhead onto efficiency, so let's just go with the space rockets to the moon plan instead. Durr.
C'mon editors. My cat could have figured out a better power scheme than this. Even the Hydrogren that is 20KM under the surface of the earth would be cheaper. New national level building codes where we force all new buildings to have solar panel roof tiles and solar colleting windows would be easier to pass by congress. Also, quite frankly, the guys that are still hacking away at cold fusion probably have a better chance of getting it all to work.
Damn I wish this was K5 so I could vote to dump this article.
Pithy, yet ultimately meaningless, phrase expressed with gusto!
You don't take photovoltaic cells to the moon, you build a factory on the moon and make the cells there. Just about everything you need is there: water, minerals and even some things that you don't find that often on Earth.
This is probably as far beyond our immediate capability as getting to the moon was to people of the 1940's - just a matter of time, money and will. The latter seems to be the most lacking.
Washington, DC: It's like Hollywood for ugly people.
Total nonsense?
Sure, you could pursue fusion.
But we may not get fusion. Should we wait
for the PERFECT energy source while we rely on
the bad ones, unstead of using a better one,
while we pursue the goal of fusion, which
(while theortically realizeable) doesn't even
have a timetable associated w/ it?
Furthermore, sure, the short-term costs would be
large, but what are the costs for building and planning a new nuclear reactor?
Solar cells on earth? We have clouds. We have day and night. The moon (thanks to an astronomical quirk) has permanent day and night. Much better
efficiency that we can get. Store it there.
Send it over, microwave style, when the terran
receiver is in place.
Or bounce it off a satellite.
Just because you can conceive of better long term ideas, why should we not pursue a better short term idea, rather than stick to one that's actually harming us?
-Slackergod
Microwave Power?...
Sim City 2000 Anyone?...
Where the hell are my Arcologies?
So, the moon receives 13000TW of power, and we only need 1% of that? Let's do a little math eh...
Solar cells are at best about 20% efficient. For the sake of my argument, that's the number I'm using. The argument stands even if you could imagine getting 50% efficiency from the falling sunlight.
They would need to cover 1% of the lunar surface on BOTH sides of the moon, because only half of the solar panels would be in sunlight at a time.
They would need to cover 5% of the surface, because the cells are only 20% efficient.
Combine those two problems, and you have 10% of the surface of the moon covered in solar panels. Add another 5% because not every portion of the surface is suitable for placing panels. Multiply the result (15% of the lunar surface covered) by about 1.5, to make up for the transmission loss from the moon to earth, and through the atmosphere. Result... over 20% of the moons surface, its TOTAL surface both visible and non, covered with solar panels to get that 130TW the author stated.
Imagine the moon with a bright shiny ring of solar sails all along the left and right edge. If you can't hear every environmentalist and presevationist crying out simultaneously in anger, you are deaf.
"I will trust Google to 'do no evil' until the founders no longer run it." Hello Alphabet.
Don't worry, the brightest industry brains work on the ozone problem. It will be solved shortly and we'll get a whole lotta power right here.
On the cow manure idea:
A new 750-kW power plant at Tinesdale Farms in Wrightstown, WI, is the first in the state to be powered by cow manure. The facility uses a "digester" to convert the manure to methane, which is then burned to generate electricity. Ag Environmental Solutions, LLC (Wrightstown, WI) owns and operates the facility, and Wisconsin Gas/Wisconsin Electric is buying the power and selling it to its customers. The manure comes from 1,800 cows at Tinesdale Farms, and it generates enough electricity to power 250 homes -- http://www.achrnews.com/.snippy./
Ever need an online dictionary?
If the lunar plan were to be adopted, I wonder what security measures would be implemented to protect this superior technology from those seeking to destroy it?
I think the whole "being on the moon" is a pretty good defense...
--
Benjamin Coates
First of all, that darn atmosphere absorbs a lot of it. Second, that's the energy that keeps you warm and feeds you (plants don't live off of love, you know).
The only way the moon as power source will be practicable will be if we move up there or figure out how to get that energy down here. Neither one is any easy task. You can pretty much forget about the first, and the second involves crazy plans with microwaves. What happens when the aiming device gets hit by a meteor, and the microwaves fry some poor shmuck? oops. Not to mention the amount of power that such a system would lose sending the signal through the atmosphere.
The only way I see space based power being practicable is with some sort of geo-synchronous elevator (the ones that are connected to the planet by a metal cable in sci-fi). Then you could put solar panels, fission/fusion or pretty much any other type of power plant up there, and just let the wires carry it down with a whole lot less risk than a microwave beam.
Don't hold your breath for any practicable space based power in our time, though.
BlackGriffen
Just for kicks and giggles, I thought I'd try to figure out how much area you'd need to cover to pick up that 1% of energy hitting the moon.
Radius of the moon: 6378.1 km
So the area of a disc of that radius is 1.278e8 km^2.
One percent of that is of course 1.278e6 km^2.
Lets construct our solar panels in a band around the equator, so that at any given time, 1% of the sunlight is being collected.
Treating the band as approximately a rectanle, so I don't have to think too hard, 1.278e6/6378.1 = 100.18 km
Now this stripe on a flat disc needs to be translated back to a band on the surface of a shpere. Approximating that band as a cylender, with hight 100.18km, and radius as that of the moon, we get approximately 4.0e6 km^2. For reference, thats tad less than half the size of the United States (9.629e6 km^2).
Build several (or several hundred) big (square-mile-plus) mirror-array collectors throughout the world (the dispersal reduces output fluctuation due to nightfall and weather).
Use the concentrated sunlight to generate steam which generates electricity which can be transmitted to grid subscribers, or to wet areas to generate hydrogen from easily available water (they hydrogen storage further reduces output fluctuations by acting as a chemical battery).
Use the hydrogen to run vehicles, electric generators for off-grid communities, and grid generators when sunlight is scarce.
The startup costs for this can't be any higher than for exploration, drilling, and refining of oil in the millions of wells we've sunk, and the resource costs aren't any lower than free gunk from the ground, and the maintenance can't be nearly as expensive as tankers and oil slicks, so this should work out fine until the sun quits on us.
--Blair
But why:
use photovoltaic
ship power back from the moon?
This was examined back in the 70s and there's a set of even better solutions. Two samples:
1) Put the actual collectors/generators in sync orbit:
Much shorter distance to ship the power.
Much greater surface area than the moon.
Negligible gravity (just tidal and station-keeping forces).
Alternatively: Use the L4 or L5 points - same distance from the Earth but still has the low-gravity and improved surface area factors.
Mine the moon for the bulk of the material, but use a catapult to launch it to orbit. (For L5 there's an orbit using one of the other L points as a lens that requires very little delta-v to perform the final injection, so the catapult does essentially all the work.) Smelt and construct it in orbit.
2) Build a STEAM plant on the ground and launch the pieces into sync orbit, where they're assembled. (Most of 'em go in reusable unmanned heavy-lifters. Much cheaper than the shuttle.)
Steam has the advantage that you don't need to do a lot of fancy processing. Just a turbine, mirrors, pipes, generators, condensers (a flat plate painted black at right angles to the sun or behind the collector mirror, with some more plumbing attached), and a trick microwave transmitter (plus an antenna farm in the desert.) You don't need much water, and it goes around and around without leaking out for decades or more, like the freon (or whatever) in a household refrigerator.
Tesla could have done it (except he'd have used VLF radio for the power feed, at considerable loss).
These proposals and several others were examined in detail by the L5 society (founded by the same Keith Henson who is now in Canadian exile over the Scientology thing).
NASA did a study on number 2, and came to the conclusion that it was too expensive. The L5 society then studied NASA's study and found an error: They'd done it in two steps:
- Design a plant.
- Design a set of vehicles to lift the parts.
The heavy-lift vehicle was sized to lift the largest single part, which was the turbine wheel, which was enormous, making the vehicle very expensive. But it turns out it was enormous only because the plant designer had gone for efficiency with no thought to the launch issue. By sacrificing 10% efficiency the turbine could be reduced to the size of the next largest part, which would enable a much smaller and cheaper rocket to do the job.
With the (unofficial) revised estimates, amortized over enough plants to feed the rate of growth of US power demand at the time, the total capital investment was a bit over a trillion bux. Sounds like a lot. But in fact it was cheaper than building any of the earthbound alternatives for the same capacity. (Fossil fuel and nuclear were both expensive - though nuclear wasn't yet politicized out of affordability - and the remaining options such as water, tidal, wind, biomass, etc. couldn't hack the demand.)
Of course that's without even considering that the fuel is free.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The generators would then convert the energy into harmless microwave beams, which would be aimed at collecting stations on Earth
Apparently this dude has never put a marshmallow in his microwave oven.
You misunderstand the technology.
The household microwave oven uses K-band microwaves. These were chosen because they're strongly absorbed by water, resulting in very efficient heating of most foods. (There are several ranges of frequencies that do that. But K band is absorbed about the right amount to cook food through rather than frying the surface or mostly passing right through.) Microwave ovens also have a very high energy density because the microwaves bounce back-and-forth and build up until they're absorbed by the food (or the transmitter magnetron, which is why they burn out if you run them too long when empty).
The "microwaves" proposed for space solar power downlinks are MILIMETER waves - chosen because they're easy to handle and go RIGHT THROUGH water without being strongly absorbed. That's mostly so they'll go through humidity and clouds without major loss - though it helps that birds don't get cooked either.
At the downlink rectenna farm the milimeter wave energy density is similar to the energy density of sunlight to maybe three times that. But the rectenna is MUCH more efficient than a solar panel at turning it into electricity. And the rectenna intercepts very little light. You can graze cattle under it.
Even if there were an issue with the waves if they hit something ELSE (and for some stuff there is - it would heat up as if a heat lamp was shining on it), aim is not a problem. That's because the downliink is a synthetic-aperture system driven by a pilot beam from the rectenna site. The pilot signal is the only thing keeping the thousands of individual transmitters in phase. So if it's lost the beam defocusses. Most of it misses the planet entierly and the rest becomes nothing more than an annoying milimeter-band radio noise.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Funny you should mention this. Did you know you can get an approximate figure of the speed of light using only a common microwave oven, marshmallows and a ruler? Try this experiment:n 34/marshmal.htm
http://www.physics.umd.edu/ripe/icpe/newsletters/
Somehow nobody has yet linked to Criswell's original article, which was published in the current issue of the Industrial Physicist, put out by the American Institute of Physics, a highly respected research physics organization in the US.
:-)
In other words, Criswell is no crackpot; this is a realistic plan. Read the article. I don't entirely agree with him - I think lunar materials could more effectively be used to construct orbiting solar power satellites - launch from the lunar surface can be very cheap using electromagnetic railgun technology, and in orbit you can get sunlight 100% of the time, not 50% (with solar incidence angle effects to worry about too). But Criswell's scheme is one of the most promising options, and should be considered seriously.
How soon could this be done? Essentially all the technology is in place - the scheme could benefit from some further developments of robotics, but a first launch date of 2010 is not unrealistic, and we could have power from the Moon before we would see anything from ANWR
Energy: time to change the picture.