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PG&E Makes Deal For Solar Power From Space
Posted by
Soulskill
on Tue Apr 14, 2009 08:15 AM
from the just-watch-out-for-the-shadow-square-wire dept.
from the just-watch-out-for-the-shadow-square-wire dept.
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."
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Recently we covered California utility company PG&E's ambitious deal with upstart Solaren to beam energy to earth from a space-based solar collector. What we didn't know is Solaren's patent also covers the alteration of weather elements with that very same system. "By heating up the upper and middle levels of an infant hurricane, they say they could disrupt the flows of air that power the enormous storms. Air warmed by tropical waters flows up through a hurricane and is vented through the eye into the upper atmosphere. Theoretically, you could heat up the top of the storm and lower the pressure differential between layers, resulting in a weaker storm. "
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Hardware: Beamed Space Solar Power Plant To Open In 2016? 449 comments
Eric_S writes "Anybody who managed to get a decent city going in Sim City 2000 remembers the microwave power plant; now it seems like a real-world equivalent might be coming up on the horizon.
The Pacific Gas and Electricity Company, per this 'interview' with the CEO of Solaren on their affiliated site, announced PG&E's plans to buy 200MW of base-load power from a Solaren beamed space solar power plant by 2016." I wish the skeptic in me would be quiet.
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Not a problem, don't be such worrywarts (Score:5, Funny)
As long as you turn off disasters, beamed solar energy is actually a fairly cost effective power solution.
Re:Not a problem, don't be such worrywarts (Score:5, Insightful)
I sometimes wonder if SimCity has done more damage to the progress of orbital solar than all other causes combined.
Parent
It think they've been duped. (Score:4, Interesting)
Re:It think they've been duped. (Score:4, Informative)
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.
Parent
Re:It think they've been duped. (Score:4, Informative)
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.
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Re:It think they've been duped. (Score:5, Insightful)
The solar constant is about 1.4 kW/m^2 in Earths orbit. I fail to see how they want to produce 200 MW with significantly less than 0.2 km^2 of collector area. Care to explain it to me?
Parent
Excellent headline (Score:5, Funny)
"PG&E Makes Deal For Solar Power From Space"
Is there any other kind?
Re:In all seriousness... (Score:5, Funny)
Parent
Re:In all seriousness... (Score:5, Funny)
Parent
Re:In all seriousness... (Score:5, Insightful)
Yes. But as the Russians found out - any energy source can be used as a weapon. The more people are dependent on it, the better. And such usage doesn't even involve violence - just mention that there might be some service disruptions, outages, etc, if you don't get your way.
Parent
Re:In all seriousness... (Score:5, Funny)
couldn't this also be used as a weapon?
"Tonight we had a most unfortunate accident. A micrometeor hit the satellite, changing it's orientation. The accident, unfortunately, destroyed a coal plant. Again.
Oh, by the way. We're raising the prices 25%."
Parent
Re:In all seriousness... (Score:5, Insightful)
No, it will never get off the ground.
Having said that, Solaren's web site is all about down to earth renewable projects. The 200MW of power the power company has pledged to buy is the equivalent of 40 commercial windmills. My guess is this is a "foot in the door" deal that cost neither party a cent but Solaren now know what the power company are willing to pay. Using this knowledge they can go back at a later date and convert the pie-in-the-sky pledge into a purchase from a normal wind/solar farm that will do the same thing for the same predetermined price.
Parent
Re:In all seriousness... (Score:5, Funny)
I'd be interested to know what effect it would have on an airport for example.
The in-flight meals would be warm for once. Now, if only someone could work out a way of beaming flavour from a satellite...
Parent
Re:Bad idea (Score:4, Interesting)
This is a horrible idea. What happens when the beamer is hit by a micro meteor nocking out the com and pointing the sat at SF?
Forget micrometeors. The real question is: what happens when Solaren goes the Enron way (and isn't bailed out by your tax dollar) and their satellite is allowed to go derelict and drift? Will it leave a narrow trail of roasted humans across California?
Parent
Re:Bad idea (Score:5, Interesting)
Everyone does that every day. It's called the sun. That's where this thing gets its energy from. However, there is a key difference between solar radiation, and the radiation that this machine produces. The reason that we have solar frequencies converted to this frequency, is because it interacts close to nothing with the atmosphere, or just about any organic particle/interference. A lot of matter interacts with very specific frequencies, which is why this frequency will only give power to the designated material. Think of an atom as a football at the center of the stadium. The electrons would be like flies in the bleachers. Now if you want to hit the flies with bullets, you have to aim to where they generally are, or you'll miss. It works kinda like that.
Parent
Re:Bad idea (Score:5, Funny)
Parent
Re:Bad idea (Score:5, Funny)
The effects of microwave radiation on high density airborne smug are still unknown
Parent
Interlock (Score:5, Informative)
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.
Parent
Re:Bad idea (Score:4, Funny)
Parent
Re:Bad idea (Score:4, Funny)
That's not a horrible idea... that's a fabulous idea :)
Parent
Re:Bad idea (Score:4, Interesting)
Considering how far the beam might deviate in 250 ms, I think the reaction time should be made much, much short. Microseconds.
True - the reaction time should be shorter. So try this: The ground station is transmitting a laser signal, which the satellite receives using a system with a VERY limited field of vision. If the signal is interrupted, the power cuts off. That way if the satellite's orientation is disturbed enough to miss the receiver, it won't be able to see the laser...
The keep-alive idea I originally posted doesn't hold up on closer inspection - there's over 100ms of latency in a radio link from the Earth's surface to geosynchronous orbit...
Parent
Re:Bad idea (Score:5, Insightful)
The problem is that a laser beam doesn't go any faster than light speed, either.
The satellite would have to determine on its own whether it's still pointing the right way.
That's why I specified that the *receiver* have a very limited field of vision. If the satellite rotates enough to be off target, it can no longer see the laser. Thus no latency issues.
Parent
Re:I've seen this (Score:5, Funny)
Fools...
Parent
Re:makes no sense (Score:5, Interesting)
Buying desert land isn't "astronomically expensive". It's about the cheapest land there is. There happens to be huge deserts of dirt-cheap (cheaper: sand-cheap) land all around California. Besides, this 2MW satellite probably doesn't even need more than about 25m^2 to receive its beam at 5x solar density. If they wanted to be really safe, they probably could diffuse it over 2500m^2, for 5W:m^2, which doesn't hurt anyone.
The efficiency here is the 30% extra incoming solar power that is otherwise lost in the atmosphere (minus some small lost amount they're tuning the beam to minimize), times the 24/7 uptime instead of about 25% terrestrial due to night/weather/seasons. That's a starting point of 520%. But the other advantage is the much larger area that thin collector sheets can cover in space. Launching costs money per mass, but the collectors can unfurl across kilometers. And the maintenance costs in microgravity/femtopressure are much lower over years, despite the remoteness. After the large initial costs, the ongoing costs per watt are extremely low.
2MW would require only about 40x40m collectors. A square kilometer collector would bring 1.3GW. The geosync satellite beaming to Fresno could receive from collectors in all kinds of other orbits pointing at the hub. This infrastructure could conceivably bring all 17TW of Earth's energy consumption into a series of ground stations from only about 114*114 Km of collectors. A few score hubs around the equator each using a few dozen GW lasers could replace all the coal currently burned for stationary power. The sky is literally the limit.
Parent
Re:makes no sense (Score:5, Informative)
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/ [celestrak.com]
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.
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