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Simcity Microwave Power by 2050?
Politburo writes "The Drudge Report supplies this interesting Senate testimony. Dr. David Criswell, director of the University of Houston's Institute for Space Systems Operations, proposes that we develop robots to assist in the construction of a lunar solar array. The power from this array would be beamed to recievers on Earth, either directly or via relay satellites. Dr. Criswell predicts that with this project, "the average American income could increase from today's ~$35,000/y-person to more than $150,000/y-person." He also attempts to put to rest the idea that microwave power is unsafe, saying, "Each power beam can be safely received, for example, in an industrially zoned area." I wonder if he's ever played SimCity 2000" And coming soon, Godzilla from a drop-down menu.
Energy Conversion Devices has developed a 30 Megawatt solar machine the size of a football field. The device produces nine miles of solar cell at a time. The amorphous solar cells are not great in terms of ultimate conversion efficiency, but they are unique in that they will put out much more power over their life time than the energy used to produce them. They are great on a watt per dollar basis.
Life is the leading cause of death in America.
the average American income could increase from today's ~$35,000/y-person to more than $150,000/y-person
It better be a lot more than that. By 2050 inflation alone should push a $35,000/year income to $225,000/year (assuming the inflation rates of the last 47 years stay about the same over the next 47).
Never approach a vast undertaking with a half-vast plan.
For all those that are "too cool" for SimCity... Microwave power was a great way to provide good-level, affordable-cost power to the citizens of your city. An array in space would power your land-bound power-station nicely, but the downside to this was that every so often it would miss the power station (oops) and fry something in your city.
Maybe if they play Simcity for awhile, they'll realize that this invention might work much better if they do, in fact, build such a power plant with a few fire-stations nearby... but I'd imagine a real-world application would have some form of laser-alignment system that has the array blocked until it's properly aligned with the receiving station.
This site also has some interesting information on beamed-power research.
There are even competitions!
"Studies have shown that people who eat peanuts live longer than those who do not eat."
The main problem would more likely be what if a cold current of air changes the refractivity of some part of the atmosphere just a little bit so that the beam goes just .1 of a degree off and cooks up a residential neighbourhood instead of providing it with electricity...
Lets check the math on this one. Air has an index of refraction of about 1.000292. The .000292 portion is roughly proportional to the density of the air, which is roughly proportional to the absolute temperature of the air. Assuming a 40,000 foot air column and a beam-to-atmosphere incidence angle of 50 degreees (power to a city in the far north or south from an equatorial-orbit power station), the deflection angle due to refraction is about 0.02 degrees or about 14 feet in total.
This 14 foot refraction is also roughly proportional to the absolute temperature of the air. Between summer (35 C) and winter(-35 C), we have a temperature range of about 23%. So the beam will wander about only about 3 feet over the most extreme temperature variations that are likely. (This calculation is only an approximation, but I am sure it is accurate enough to show that refraction is not a big deal.)
Others will have to comment on scattering.
Two wrongs don't make a right, but three lefts do.
Uh, we bounce lasers from earth to the moon, all day long, every day. They are measuring the distance to the moon, using the speed of light. It doesn't diverge any practical distance at all.
Read here
We are hitting a reflectr 46cm^2 thats A LOT less than a mile deviation. the 46cm is just for things like vibration, and aiming issues.
BTW, this laster tells us the moon is drifting away from the earth, at 3.8cm per year!
After reading the article, it appears the max power of the beam that reaches individual substations is 20% of noon-time sunlight.
I think the FUD slashdot users have built into this system can now safely be ignored.
-Malakai
A Dragon Lives in my Garage
OK, here's my quick off-the-cuff calculations on this:
.6 seconds, as opposed to the approx 2 seconds rtt to luna)
/second. Worst-case, the beam travels the 2km in exactly the 2 seconds of rtt. The hundred meters of beam width will pass over any point along that path in approx .1 seconds, adding 10 watt-hr/sq meter, i.e., 10 watt-hr to our worst-case prostrate person. If I'm doing my calculations correctly, that's about 9000 calories. I occlude about 1 square meter, and mass about 100 kilos. One calorie raises one gram one degree celcius, so that energy would raise my body temperature by .09 degrees celsius, which I doubt I would notice.
.000001 seconds, and then stopped dead for 2 seconds. That would deliver 200 watt-hrs, elevating the temperature of prostrate people in the vicinity by about 1.8 degrees celsius, which would probably be noticable, but unlikely to be deadly (and extremely unlikely to melt the ground to a puddle of glowing magma...) (of course, all of this assumes that the person is absorbing 100% of the transmitted energy.) However, it seems to me that there are reasonably simple ways to make this sort of failure much more difficult (I'm thinking that the relay station is in two components, a transmitter and a colimator, tethered together with the center-of-gravity of the entire structure being in geosync and tidal forces providing tension on the tethers. Put a wave-guide assembly between the transmitter and the colimator so that mis-alignment will turn it from a wave guide into a reflector. That would mean that a drift off-target would require the entire assembly to move, so you've got a lot of inertia guaranteeing that drift will tend to be constant, as opposed to jerking far off target and then stopping suddenly)
assumptions:
the beam is 3.6Gw (which is a fairly large amount...)
collector is 100 M on a side (10,000 sq m)
nearest un-shielded habitation is 2km away
out-of-alignment condition will be noticed immediately, but will take one speed-of-light rtt to shut down (note, if the collector is on the lunar surface, but relay satellites are in geosync, then the rtt from the geosync satellites is about
worst-case scenario is a prostrate person occluding 1 sq. M of space.
calculations:
The beam is delivering 360 Kw/sq m, 100 watt-hrs/sq meter
Now, the *really* worst case scenario would be if the beam traveled the 2Km in
Pound! Bang! Bin! Bash! is this a shell script or a Batman comic?