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.
First a minor quibble; Space-based cells produce about 4-5 times as much energy as ground based ones, as the sun is always directly "overhead", and there's no clouds (or air) to block them.
And we aren't really working to make solar cells lighter so much as cheaper.
But the real solution seems simple to me - instead of making solar cells on earth and paying the exorbitant shipping costs, we need to manufacture them in space.
I'll even go so far as to admit that there are more.torrents up on TBP that are pointing to files being distributed without authorization than there is the alternative.
I think you're saying the amount is moot, and perhaps in Sweden it is. But if this were being tried in the USA, I'd argue the relative amounts are far from moot, and I for one would be very interested in knowing what the percentages are. Some posters claim it's less than 20%, some claim more than 80%. Is there anywhere that has some real data? I.e. If I grab 100.torrents pointed to by TPB, how many can I expect to point to material that is being distributed illegally?
Granted this is an as yet unrealized technology, but I really wonder what the lumens per watt will be.
For reference a standard 48" T8 fluorescent is about 80 lumens per watt, Compact fluorescent is around 65 lumens per watt, and a 60w A19 bulb (the "normal" light bulb) is about 15 lumens per watt.
Cree has some Gallium nitride LEDs that (they claim) produce a record breaking 130 lumens per watt, but they also have some 100 lumens per watt LEDs and they're also gallium nitride.
Cost of production isn't totally meaningless, but over it's 20 year life, 5 watts means more than $100.
Don't be silly, prison is nothing like school; In prison, you don't have to ask permission to use the toilet. In prison, you have free time when you can think. In prison, you can get time off for good behavior. If you do well in school, they give you extra work. If they make you work in prison, they have to pay you. If you escape from prison, the law comes after you. If you escape from school, the law comes after your family. If prisoners get into fights, the guards separate them. There are organizations dedicated to monitoring conditions in prisons, and keeping them from being inhumane.
Stirling Engines may be the most power efficient, but they aren't the most cost efficient.
Big plants usually use turbines because they can tune the conversion/cost efficiency to whatever is appropriate for their application. Add more stages (fans), improve efficiency but raise the cost.
Before reading the fine article, I thought it would be a PR piece for Ausra.
If you read the stuff at their website, http://ausra.com/, they answer a lot of the questions that have been, and doubtless will be asked here;
It's possible to store thermal energy and use it to produce electricity at night. Some places do receive more sunlight than others, and plants built in those places would be more efficient. They have a nice PDF that shows (among other things) the normal solar radiation for different areas - plants work better in deserts than in river valleys, but there are plenty of places you can build them that are cost effective. Ausra isn't vaporware - they already build a plant in Australia, and they are building one in southern California.
The current plant is cost competitive with scrubbed coal, and future plants are supposed to be on par with unscrubbed coal plants. That last may be hype, but at the very least they can already produce electricity for less than 12 cents a kilowatt, and cutting that in half doesn't seem unreasonable.
Even so, at best these kinds of plants will only supplant oil and coal burning electric plants. We're still going to burn oil in our cars, home heaters, etc.
Disclaimer: I am not affiliated with Ausra, but most of my information about them comes from them, or their press releases, so take it with a grain of salt.
If the idea is to pick an email address that isn't in use, I recommend one ending with ".invalid" as in "address@is.invalid" or "noreply@domain.invalid"
I can see a difference between 600 and 1200 DPI on a printed page, but I can't see any difference between 1600 and 2000 DPI. But I don't think it's DPI that really defines the limit here; According to http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html there are about 120 million rods in the human eye. Even though they aren't evenly distributed, I'd hazard that a 12k x 10k display will be close enough to human perception that further "improvements" in resolution won't be discernible.
We aren't there yet, but it doesn't seem all that far off either.
Instead, look at the fact that it is the ONLY form of AE that can serve as base load. All others are intermitant.
Ausra doesn't say much about how they plan on doing it, but they claim they can store heat energy for use when the sun isn't shining. I'd say government research on storing thermal energy is worthwhile, but frankly, it seems like the private sector is doing that research already.
I thought the point of monitoring the government while they montior us wasn't so much because it's right, but because it's the best we can do. If the only alternatives are "The government knows everything, and so do you" and "The government knows everything, and you don't" then I'd go with the first option. Yes, the first option sucks, but it may very well be that the option "Keep stuff secret from the government" isn't available.
... no matter how high a sampling rate is, it can never contain all of the data present in an analog groove,...
Records are composed of molecules. At a small enough scale, they essentially are digital. Even if every single molecule was placed exactly correctly, a record grove's displacement would still be less accurate than a 32 bit sample. Likewise, the molecules are dragged passed the needle at a discreet rate. Although both rate and depth are much higher than a CD, there is a digital sampling rate and number of bits per sample that would be superior.
I seem to remember the Commodore 64 being instant on.
Really? I remember waiting a very long time. One of the major advantages of Fastload (TM) was that it by-passed the god-awful slow memory test on power up. I suppose "instant" is a matter of perspective.
For comparison, corn produces about 0.15 tonnes per hectare, hemp about 0.30 tonnes, and canola (rapeseed) only 1.0 tonnes. So if he's right, it's a very good oil producer, on the order of much harder to grow oil producers like avocado (2.2) or coconut (2.3).
Most kids in my school thought of it as a baby sitting service, not a place of education. Want kids to be interested in school? Give them an actual reason to do well. Let them leave once they have achieved a minimum level of competence in the core subjects. My guess is that about half the students (the half that currently do not go on to college) would work pretty hard at learning the subjects if they knew that once they had mastered them, they would no longer be subject to the school system. Then set up a decent secondary education system, for all those that decide that they need more education, after they've had a taste of the real world.
Many, many people go to college for reasons other than "increasing their money making potential",...
her education was worth all the effort and every penny. She is more rounded, has more confidence and simply learned a great deal.
Going to school is not the only way to learn something.
Solar energy is available 24/7 in space, but it's only about 3 times better than on the surface of the earth. If we could put solar cells into orbit at zero cost, then a SPS system could be cheaper than current tech. One way to do that might be to manufacture them in space in the first place, say by using raw materials from a LEO asteroid.
But making SPS for power on earth isn't the low hanging fruit of space. The first thing we should make is generic satellites. Imagine a standard body satellite with a solar array, an orbital stability tether, a massive gyroscope, and already in orbit. Now if you're a telecommunications company, you don't need to launch all that extra junk, just the "brains" and maybe an antenna. Perhaps they could even custom build satellites to order. The savings in weight/dollars just from already planed launches would be in the billions. Once we can make the satellites we're already paying millions to launch now in space, then making SPS should be cake.
Slashdot Mirror
First a minor quibble;
Space-based cells produce about 4-5 times as much energy as ground based ones, as the sun is always directly "overhead", and there's no clouds (or air) to block them.
And we aren't really working to make solar cells lighter so much as cheaper.
But the real solution seems simple to me - instead of making solar cells on earth and paying the exorbitant shipping costs, we need to manufacture them in space.
-- Should you believe authority without question?
I think you're saying the amount is moot, and perhaps in Sweden it is. .torrents pointed to by TPB, how many can I expect to point to material that is being distributed illegally?
But if this were being tried in the USA, I'd argue the relative amounts are far from moot, and I for one would be very interested in knowing what the percentages are.
Some posters claim it's less than 20%, some claim more than 80%.
Is there anywhere that has some real data?
I.e. If I grab 100
-- Should you believe authority without question?
Granted this is an as yet unrealized technology, but I really wonder what the lumens per watt will be.
For reference a standard 48" T8 fluorescent is about 80 lumens per watt,
Compact fluorescent is around 65 lumens per watt,
and a 60w A19 bulb (the "normal" light bulb) is about 15 lumens per watt.
Cree has some Gallium nitride LEDs that (they claim) produce a record breaking 130 lumens per watt,
but they also have some 100 lumens per watt LEDs and they're also gallium nitride.
Cost of production isn't totally meaningless, but over it's 20 year life, 5 watts means more than $100.
Nice to know that these "may be competitive with other forms of power even after solar subsidies are phased out."
Any idea what the unsubsidized cost per watt is today?
-- Should you believe authority without question?
Spamhaus, and most of the other anti-spam lists, are essentially boycott organizers.
They may not do much personally, but they are advocates for action.
-- Should you believe authority without question?
Hard to find a jukebox these days that charges less than 25 cents a play.
Yeah, I know it's not the same, I'm just saying that the idea of charging per play is hardly a new, untested, unworkable one.
Don't be silly, prison is nothing like school;
In prison, you don't have to ask permission to use the toilet.
In prison, you have free time when you can think.
In prison, you can get time off for good behavior. If you do well in school, they give you extra work.
If they make you work in prison, they have to pay you.
If you escape from prison, the law comes after you. If you escape from school, the law comes after your family.
If prisoners get into fights, the guards separate them.
There are organizations dedicated to monitoring conditions in prisons, and keeping them from being inhumane.
Stirling Engines may be the most power efficient, but they aren't the most cost efficient.
Big plants usually use turbines because they can tune the conversion/cost efficiency to whatever is appropriate for their application.
Add more stages (fans), improve efficiency but raise the cost.
Before reading the fine article, I thought it would be a PR piece for Ausra.
If you read the stuff at their website, http://ausra.com/, they answer a lot of the questions that have been, and doubtless will be asked here;
It's possible to store thermal energy and use it to produce electricity at night.
Some places do receive more sunlight than others, and plants built in those places would be more efficient.
They have a nice PDF that shows (among other things) the normal solar radiation for different areas - plants work better in deserts than in river valleys, but there are plenty of places you can build them that are cost effective.
Ausra isn't vaporware - they already build a plant in Australia, and they are building one in southern California.
The current plant is cost competitive with scrubbed coal, and future plants are supposed to be on par with unscrubbed coal plants.
That last may be hype, but at the very least they can already produce electricity for less than 12 cents a kilowatt, and cutting that in half doesn't seem unreasonable.
Even so, at best these kinds of plants will only supplant oil and coal burning electric plants.
We're still going to burn oil in our cars, home heaters, etc.
Disclaimer: I am not affiliated with Ausra, but most of my information about them comes from them, or their press releases, so take it with a grain of salt.
-- Should you believe authority without question?
Unlike professors, who are never wrong, always give complete answers, are totally without bias and never mislead.
Seriously, what source of information isn't sometimes wrong, incomplete, biased, or misleading?
-- Should you believe authority without question?
If the idea is to pick an email address that isn't in use, I recommend one ending with ".invalid" as in "address@is.invalid" or "noreply@domain.invalid"
I can see a difference between 600 and 1200 DPI on a printed page, but I can't see any difference between 1600 and 2000 DPI.
But I don't think it's DPI that really defines the limit here;
According to http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html there are about 120 million rods in the human eye.
Even though they aren't evenly distributed, I'd hazard that a 12k x 10k display will be close enough to human perception that further "improvements" in resolution won't be discernible.
We aren't there yet, but it doesn't seem all that far off either.
-- Should you believe authority without question?
Ausra doesn't say much about how they plan on doing it, but they claim they can store heat energy for use when the sun isn't shining.
I'd say government research on storing thermal energy is worthwhile, but frankly, it seems like the private sector is doing that research already.
-- Should you believe authority without question?
I thought the point of monitoring the government while they montior us wasn't so much because it's right, but because it's the best we can do.
If the only alternatives are "The government knows everything, and so do you" and "The government knows everything, and you don't" then I'd go with the first option.
Yes, the first option sucks, but it may very well be that the option "Keep stuff secret from the government" isn't available.
-- Should you believe authority without question?
Street musicians still make money.
A "professional" musician I know claims he makes more money on the street than his does from his label.
-- Should you believe authority without question?
Records are composed of molecules. At a small enough scale, they essentially are digital.
Even if every single molecule was placed exactly correctly, a record grove's displacement would still be less accurate than a 32 bit sample.
Likewise, the molecules are dragged passed the needle at a discreet rate.
Although both rate and depth are much higher than a CD, there is a digital sampling rate and number of bits per sample that would be superior.
-- Should you believe authority without question?
Yeah, but who would do such a thing? http://www.phoronix.com/scan.php?page=article&item=870&num=1
Really? I remember waiting a very long time.
One of the major advantages of Fastload (TM) was that it by-passed the god-awful slow memory test on power up.
I suppose "instant" is a matter of perspective.
-- Should you believe authority without question?
I tend to agree. Do you have any numbers for how it compares to hemp or rapeseed in that regard?
-- Should you believe authority without question?
Lex Worrall, chief executive of Helius Energy, claims Jatropha can produce 2.7 tonnes of oil per hectare. http://www.timesonline.co.uk/tol/news/world/article2155351.ece
For comparison, corn produces about 0.15 tonnes per hectare, hemp about 0.30 tonnes, and canola (rapeseed) only 1.0 tonnes.
So if he's right, it's a very good oil producer, on the order of much harder to grow oil producers like avocado (2.2) or coconut (2.3).
Still 1/5 of algae though.
-- Should you believe authority without question?
My favorite is still NUMOFF.COM, which as the name implies, turns off the numlock key.
Unfortunately, I was unable to find the original 8 byte version, All I have is this bloated 11 byte one;
B8 40 00 8E D8 80 26 17 00 DF C3
-- Should you believe authority without question?
Most kids in my school thought of it as a baby sitting service, not a place of education.
Want kids to be interested in school? Give them an actual reason to do well.
Let them leave once they have achieved a minimum level of competence in the core subjects.
My guess is that about half the students (the half that currently do not go on to college) would work pretty hard at learning the subjects if they knew that once they had mastered them, they would no longer be subject to the school system.
Then set up a decent secondary education system, for all those that decide that they need more education, after they've had a taste of the real world.
-- Should you believe authority without question?
Going to school is not the only way to learn something.
Yes it is, but that doesn't stop it from having other definitions.
Solar energy is available 24/7 in space, but it's only about 3 times better than on the surface of the earth.
If we could put solar cells into orbit at zero cost, then a SPS system could be cheaper than current tech.
One way to do that might be to manufacture them in space in the first place, say by using raw materials from a LEO asteroid.
But making SPS for power on earth isn't the low hanging fruit of space.
The first thing we should make is generic satellites.
Imagine a standard body satellite with a solar array, an orbital stability tether, a massive gyroscope, and already
in orbit.
Now if you're a telecommunications company, you don't need to launch all that extra junk, just the "brains" and maybe an antenna.
Perhaps they could even custom build satellites to order.
The savings in weight/dollars just from already planed launches would be in the billions.
Once we can make the satellites we're already paying millions to launch now in space, then making SPS should be cake.
-- Should you believe authority without question?