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PG&E Makes Deal For Solar Power From Space
N!NJA writes "California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016. Solaren would generate the power using solar panels in Earth orbit and convert it to radio-frequency transmissions that would be beamed down to a receiving station in Fresno, PG&E said. From there, the energy would be converted into electricity and fed into PG&E's power grid."
Plus in space solar power is available constantly, rather than being affected by night time, winter hours and weather. As they point out you don't have to pay for the real estate, just the trip to get there.
And it gives more consistent power because you don't get dust settling on the panels. I realise that sounds stupid, but dust can reduce efficiency by a lot in a few years; your costs go up because you have to pay people to be cleaning acres and acres of solar panels.
Classical Liberalism: All your base are belong to you.
There are a number of points you can choose that are geostationary and in shadow less than 2% of the time (as I recall the 1970s proposal). Other schemes call for having multiple satellites that hand off to each other. This proposal is I think of the former variety.
Classical Liberalism: All your base are belong to you.
These beaming systems have interlocks pointed back from the ground receiver to the satellite. If the two get out of alignment, the satellite immediately loses the ground signal, and immediately stops transmitting.
Besides, the beamed power density doesn't have to be very high per square meter. If it's just concentrated 5x from its density in space, it's 6.5KW:m^2. At this system's 2MW transmission rate, is only 308m^2, or a square 17.5m on a side. If it's really RF, even if the interlock failsafe failed, the beam wouldn't do much except fry some unshielded electronics in the way until something else shut it down. I'm sure the multiple layers of government regulators will ensure a lot of "deadman switches" to stop the only thing that everyone guesses could go wrong.
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make install -not war
The trick to remember is that the Earth is actually quite a small part of the sky when seen from a satellite in geostationary orbit. It seems big to us, but it's just a pale blue dot after all.
Classical Liberalism: All your base are belong to you.
Again, no. The microwaves don't interact with organic matter, they pass through. You're not getting cancer from TV broadcasts or mobile phone towers either.
Classical Liberalism: All your base are belong to you.
I mean, what's the worst that can happen when you're beaming 200 Megawatts of energy into my town?
Right now a fusion reactor is beaming sunlight (@ 1366W per square meter, on average) * 271.4 square km of energy at luminal frequencies alone which if I do the math right (even at this level it is by no means sure, I could be off by three orders of magnitude or something, yes I am that dyslexic about numbers) works out to about 370 gigawatts.
The amount of energy is pretty irrelevant by itself, aside from what it can add to the grid.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
How about I convince you they're planning to deliver only 2MW, not 200MW.
They say they'll reach a 17GWh:y delivery once the platform is stable. There's 8765.81277 hours in a year, so that's 17 billionWh / 8765.81277h = 1.9393524 million watts.
The solar "constant" in geosync Earth orbit (about 35Km elevation) is 1366W:m^2. That's 1419.73089m^2, or 0.00141973089Km^2, significantly less (0.709865445%) than 0.2Km^2.
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make install -not war
During most of the year, geostationary satellites spend 100% of the time in sunlight. During "eclipse season" (which happens around the spring/fall equinoxes), they get eclipsed, for a few minutes up to about 70 (at the peak of the season). A discussion of this can be found here: http://celestrak.com/columns/v04n09/
During those times, you could redirect from another satellite, use an alternative power source (batteries, capacitors, fueled generators, etc), and/or have a "brownout". Power outages suck, but if you're in a place where conventional power sources are unavailable/impractical/infeasable, it's better than nothing.
The meek may inherit the earth, but the strong shall take the stars.
I see you aren't an electronics geek, it's simple to make a crystal radio that's powered by nothing more than the radio waves floating around you =) Oh and the solution is simple, you use a feedback loop. You have a continue signal on the ground that tells the satellite to send power, if the beam gets misaligned the ground station loses power and the continue signal stops and the satellite shuts down transmission.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
TFA's math is wrong. TFA says specifically
1700 GWh in an 8700 hour year is just under 2MW. 200MW is enough power for 100,000 homes at 2KW each (a low average), so even their math that 1700GWh is "the annual consumption of 250,000 average homes" is wrong. I think their quoting the numbers in the contract is more reliable than their arithmetic.
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make install -not war
You answered your own question. It cant produce a narrow beam, which is the same reason why it cant cook anybody. You have a large diameter beam (kilometers in diameter) at a low power density (similar to the energy density of sunlight) and a huge rectenna array (say, covering many farmers fields by being upheld on stilts). Yes, this works. I have studied it. Smarter people than you or I have studied it. I swear to god NOBODY on slashdot understands power density. Every frikin time this subject comes up its always "its a weapon!"
Now economic viability and possible electronic interference you can go and argue all you want.
Quitters never win, Winners never quit, But those who never win and never quit are idiots.