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Tapping Solar Wind's Renewable Energy
A few folks noted a story making the rounds about the huge energy potential just blowing past the planet in the form of solar wind. This research involves putting a satellite into orbit with a thousand-meter cable and a 5,000-mile sail to generate more power than the earth currently uses.
Yes, you are. That makes about as much sense as Guam flipping over. The Earth is so large that this would never be able to move it. Further, as the article states, this isn't a sail, rather it's a collector of electrons.
Hoist Number One and Number Six.
Click me. This article is paywalled after you read a few stories, but the paywall is a javascript popup. Noscript lets you read the article.
warning; it's goatse
Your fears are about as substantial as Chicken Little's over the sky falling.
In the exact same way that solar power is considered renewable, and hyrdo power is considered renewable, and wood burning power is considered renewable.
Yes when the sun comes to the end of its life all of those stop. But there are bigger issues at that point...
Launch costs. I'm assuming these will be in geo-synchronous orbit, rather than LEO, so the cost to orbit would be higher.
Reading the article, the larger sized calculations are for example, and not very realistic. How would you unfurl an 8,400 km sail from a current launch vehicle?
Planning to be moderated ± 1: Bad Pun.
You might wanna re-read the summary...it would be using a cable.
You might wanna re-re-read the summary.
The cable is (depending on size of sail) less than 1 km long.
Thus it would be sail -> up to 1km cable --> orbiting power sat ----- ? ----> earth
The ? is either a laser or microwave.
Plus, you could just pick out lobsters precooked and ready to eat straight from the ocean!
God invented whiskey so the Irish would not rule the world.
Compared to fossil fuels it isn't going to run out any time soon. Peak oil is in a few years to a few decades, peak solar output is just before it turns into a red giant a few billion years from now.
The authors original paper ( http://www.lpi.usra.edu/meetings/abscicon2010/pdf/5469.pdf ) is about building the largest practically possible chunk of a dyson sphere. This is essentially the largest piece they think we are capable of building with current technology.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
My question exactly. Or almost exactly -- from the number of zeroes you're using the European "billion" (million million) rather than the North American (thousand million).
But even assuming the latter, a 1 km square sail gives roughly 6 times the energy Earth uses currently (by their figures). And a 1 km square sail is a heck of a lot easier to build than an 8000 km square one.
That number, though, surprises me. Sunlight flux is less than 1.5 kW/square meter at Earth's distance. Call it 2 GW per square kilometer -- nowhere near Earth's energy use (in the 10-20 TW range)*. This is talking about tapping solar wind rather than sunlight, but I find it hard to believe that solar wind flux is that many orders of magnitude more energy intensive than sunlight. If it is -- and despite Earth's magnetic field -- global temperatures are going to be driven mostly by solar wind effects. The numbers in TFA must be wrong, i.e. typical popular science reportage.
(* TFA says an 8,400 km square sail will produce "a billion billion gigawatts", which works out to over 14 terawatts per square kilometer. The numbers are totally fucked up. Somewhere in there I think somebody confused meters with kilometers and/or watts with kilowatts.)
-- Alastair
> Just HOW do you suppose you are going to accomplish [depopulation]?
As an empirical matter, the most effective known formula involves these steps: (1) provide educational opportunities for young women; (2) provide modest economic growth; (3) wait one generation. Items (1) and (2) frequently go very well together.
2*3*3*3*3*11*251
Also, the paper was presented at an astrobiology conference. They are suggesting that an alien civilization is more likely to have built one of these than an actual Dyson sphere (because it seems possible with our own technology within the next 100 years, unlike a Dyson sphere), and they are wondering if we would be able to detect it using our current instruments and techniques. That's the focus of the paper, not the idea that we should actually begin building one.