Space Based Solar Power Within a Decade? 371
Nancy Atkinson writes "A new company, Space Energy, Inc., says they have developed what they call a 'rock-solid business platform' and they should be able to provide commercially available space based solar power within a decade. 'Although it's a very grandiose vision, it makes total sense,' Space Energy's Peter Sage told Universe Today. 'We're focused on the fact that this is an inevitable technology and someone is going to do it. Right now we're the best shot. We're also focused on the fact that, according to every scenario we've analyzed, the world needs space based solar power, and it needs it soon, as well as the up-scaling of just about every other source of renewable energy that we can get our hands on.'"
Re:So long cables running from space to earth? (Score:5, Informative)
you clearly did not RTFA. microwave.
Re:So long cables running from space to earth? (Score:4, Informative)
Re:So long cables running from space to earth? (Score:3, Informative)
How exactly are they going to get the power back down from space?
Microwave transmission [wikipedia.org].
Every Time I see "Solar Power Satellite" (Score:1, Informative)
Re:I LOVE stories like this (Score:4, Informative)
Obvious by it's absence (Score:4, Informative)
Notably they fail to mention what is expected to be the long pole in the tent - launch costs. Even if Musk and SpaceX succeed, launch costs will still be at least an order of magnitude higher than what is estimated will be required for commercial success of space based power plants.
Re:Ah, microwave... (Score:2, Informative)
This isn't an ion cannon. The effects at the transmitter are minimal, so I'd expect they won't do much to a satellite.
http://permanent.com/p-sps-bm.htm [permanent.com]
Re:So long cables running from space to earth? (Score:4, Informative)
If this article can be believed it's hardly as dangerous as you're making it out to be.
http://permanent.com/p-sps-bm.htm [permanent.com]
Re:So long cables running from space to earth? (Score:3, Informative)
It seems like it could be made pretty safe. Have the receiver constantly sending a keep alive signal back to the satellite as long as the power beam is on target. If the beam drifts off target for any reason, the keep alive stops, and the satellite will stop sending down energy until it can be properly realigned. It does mean that you lose power for a bit, but that's probably preferable to losing power AND nuking some poor schmuck's house.
Military applications (Score:4, Informative)
To deliver power to a certain places in Iraq and Afghanistan it costs well over $1USD/kWh, not mention the loss of human life.
The pentagon is seriously considering SBSP as a viable way to deliver power to not only these locations, but other places of humanitarian interest.
The technology to deliver and deploy SBSP payloads (for it will take many deployments) already exist. Improvements will undoubtedly be made, and with the hopeful completion of NASA's Ares V [nasa.gov] cargo launch vehicle SBSP will be economical for the rest of us. (under 20cents(USD)/kWh.)
As for the microwave radiation concern, it is not as scary as commonly depicted. (Can anyone recall the tale of the discovery of microwave radiation as a cooking tool--something to do with a Snickers bar melting in a pocket? [Who the heck carries a Snickers bar in their pocket?]) If the size of the receiving antenna is increased, the power of the transmitted signal may be decreased on a W/m scale. With a transmitter that can 'dither' the signal over a rather wide swath one can abate errors associated with tracking, solar anomalies and human error.
Military applications, however, are not quite as concerned with stray microwave beams.
Do not forget that SBSP is exposed to the sun for 24 hours--no interruptions!
On another note the Japanese are working on developing devices that may convert solar energy to transmittable energy in upwards of 40% efficiency by converting solar power to laser. [treehugger.com]
Re:So long cables running from space to earth? (Score:5, Informative)
Re:So long cables running from space to earth? (Score:3, Informative)
You know how the latency in a satellite kills that way of communications for gaming, correct? Considering that light travels 180,000 miles per second, and that geostationary satellites are 20,000 miles away minimum, that is a good fraction of a second where the satellite can be knocked out by space debris or what not. Imagine the swath it's aiming at with just a small degree, we are probably talking at least dozens of miles.
OTOH, the energy would be distributed along that entire area, but still.
Re:I LOVE stories like this (Score:3, Informative)
50 tons of gold would be worth approx. $1,558,720,000
Cost of 1 shuttle launch $450,000,000
Ok so some math here, let me see carry the 1...
Ok that leaves us with a measly $1,108,720,000 ok your right fuck that idea, thats not worth it at all... hehe
Re:Feasible, but practical? (Score:3, Informative)
I noticed that too. In particular, the comment about shipping energy around the national (and, conceivably, international) grids.
I suppose one advantage of SBSP is that the aim on the satellite transmitters could be adjusted to one of several ground receiving stations, which would allow the power to travel over smaller distances on the grid. Whether this could actually make up for inverse square losses due to longer transmission paths, I don't know. Still, it's an interesting advantage to SBSP that I hadn't previously considered.
Still, I think you're on the ball with regards to this being far more useful for remote, emergency & military power, and so on, rather than as any kind of baseload gen... it's clearly far too expensive for that, even compared to aging maintenance-intensive nukes, ground-based photo-voltaic solar, and wind, let alone cheap power like gas turbines and coal plants.
Re:Yep (Score:2, Informative)
Yeah sounds pretty hard, fuck it. Thankfully we had the smartest person in the world to indicate the error of our ways. Thanks OP!
Crazy units (Score:3, Informative)
"Almost 200 million gigawatts of solar energy is beamed towards the Earth every second, which is more energy than our civilization has used since the dawn of the electrical age."
Let's see. 200 million gigawatts * 1 second = 0.2 exajoules. Worldwide energy consumption is on the order of hundreds of exajoules per year.
This article must be using the wrong units somewhere, but I guess that's just the status quo nowadays.
Re:Tiny effect (Score:3, Informative)
You do realize that microwaves don't have any effect besides heating water (and other bipolar molecules) and causing sparks to fly off metal (which is how the energy gets collected)? They aren't scary nuclear radiation, they just make you uncomfortably hot. Make the beam wide enough and it won't hurt anyone or anything.
Re:God's Speed and Good luck! (Score:3, Informative)
Nobody cared during the life of Nikola Tesla.
Although his idea was that everybody/everything would have a collector antenna to tap in. Not very commercial for him, the project was stopped.
Yes, granted the are gigajoules sent the Earth every s, for *free*, its still far to be the salvation from fuel...
Re:So long cables running from space to earth? (Score:3, Informative)
Umm, you are so wrong, one of the power plant options was satellite microwave. I remember it clearly, and it's mentioned in the wikipedia entry [wikipedia.org]. Obviously you don't get to build the space based part, just the ground based receiver. As I recall, it was an expensive option and I rarely used it.
Not so much... (Score:5, Informative)
First figure that the cost of putting a kilo in orbit is NOT going to go below $300, period. Not if you're lifting stuff into space with any sort of chemical rocket. So the cost of a kilowatt of SPS power is going to be MUCH higher. OK, you're PV cells are lets say 400% more efficient, but then you also have to build a giant rectenna or 10 and losses beaming power back to Earth then eats up 50% of your efficiency gains, so hey, it is only 10x more expensive than putting it in Nevada!
The other problem is we still have no idea how to build really large structures in space. Obviously it can be done, but anyone who thinks the basic engineering of that solution will not cost 100's of billions of $ is well, another O'Neil, and if he was even order of magnitude on with his numbers it would be happening now. It is a lot harder than people think. It is a lot harder than engineers think (who usually only underestimate by about 300%).
What we need is HUGE quantities of power. The US needs 15 TERAWATTS of renewable energy installed base in the next 20 years. The gating factor is cost, not efficiency. Instead of screwing around for 20 years figuring out how to build it in space, for no clear benefit, we need to just BUILD IT NOW. Time is a wasting.
Re:So long cables running from space to earth? (Score:3, Informative)
There are NOT MASSIVE LOSSES IN THE GRID! "Although losses in the national grid are low, there are significant further losses in onward electricity distribution to the consumer, causing a total distribution loss of about 7.7%.[6] However losses differ significantly for customers connected at different voltages; connected at high voltage the total losses are about 2.6%, at medium voltage 6.4% and at low voltage 12.2%.[7]"
-- http://en.wikipedia.org/wiki/National_Grid_(UK) [wikipedia.org]
Re:Do the math, folks (Score:5, Informative)
Parent post is good, but it's really much simpler than that.
Cost per kg to send something to GEO orbit: $10,000
Cost of solar cells per kg: $400
Space-based cells produce about twice as much energy as the same panels on the ground.
So until launch costs drop to equal to the cost to build the panels, it'll be cheaper to just build twice as many panels on the ground.
Space-based power is a factor of 20 away.
Re:Tiny effect (Score:3, Informative)
Nope, the proposed frequency is the same as microwave ovens.
http://en.wikipedia.org/wiki/Solar_power_satellite#Wireless_power_transmission_to_the_Earth [wikipedia.org]:
To minimize the sizes of the antennas used, the wavelength should be small (and frequency correspondingly high) since antenna efficiency increases as antenna size increases relative to the wavelength used. More precisely, both for the transmitting and receiving antennas, the angular beam width is inversely proportional to the aperture of the antenna, measured in units of the transmission wavelength. The highest frequencies that can be used are limited by atmospheric absorption (chiefly water vapor and CO2) at higher microwave frequencies.
For these reasons, 2.45 GHz has been proposed as being a reasonable compromise. However, that frequency results in large antenna sizes at the GEO distance. A loitering stratospheric airship has been proposed to receive higher frequencies (or even laser beams), converting them to something like 2.45 GHz for retransmission to the ground. This proposal has not been as carefully evaluated for engineering plausibility as have other aspects of SPS design; it will likely present problems for continuous coverage.
http://en.wikipedia.org/wiki/Microwave_oven#Principles [wikipedia.org]
A microwave oven works by passing non-ionizing microwave radiation, usually at a frequency of 2.45 gigahertz (GHz) (a wavelength of 12.24 centimetres (4.82 in), through the food.
(Emphisis mine)
There is also some infared wavelengths that can be used, but IIRC, they're less efficient.
Right! (Score:3, Informative)
All we have to do is put a gigaton or so of unobtainium into geosynchronous orbit and then weave a cable 35,000 miles long out of it, lower it to the Earth, and then figure out how to make a vehicle that can climb a cable for 35,000 miles.
Worse yet, if we fail it is a serious problem. We can't even build suspension bridges with 100% reliability. Whoever thinks we're going to build a beanstalk right on the first try is probably wrong.
I put beanstalks into the 'who knows what might be possible in a century or two' category. Even if we DID know how to make one it would likely take decades or more to build it.
(there are better ideas than beanstalks, launch lines and fountains come to mind).