Why does anyone even think this would be a problem?
Did the Homo Erectus walking from Africa to Asia in small family groups often murder each other?
Did the Polynesian cross-pacific crews commit suicide en-route?
Did the native americans all go crazy while crossing the land bridge on the way to becoming native americans?
Does this ever happen on submarines?
NASA has been worried about isolation, sex, and infighting since the 60s. Maybe they should stop asking themselves what will happen, a large group of nerds probably isn't the first place you go to find out about these topics.
Oh god no. According to the EIA average US house uses about 30 kWh a day.
Lead-acid batteries do not like to be run down past 50%, and if you want them to last even a few years, 65% is the minimum. So if you want one day of storage, you'll need 75 kWh worth of batteries. A 75 kWh lead-acid battery bank would fill a bedroom. That is not small.
Li-ion has two to three times the energy density. It can also be repeatedly drawn down to 20%, and that number is improving. So for that same 30 kWh home, you would need about 40 kWh of li-ion, so the total battery bank size would be at *least* 4 times smaller, about the size of a small fridge.
But what you really need to do is just improve the homes. Last year I was burning about 15 kWh a day on average, about 1/2 the average US home, and significantly less than the 25 kWh average for Canada. I replaced all the light bulbs with LEDs and upgraded my computer (which uses less energy), and since then my average is 11 kWh. With li-ion, that would be a beer fridge.
A while back an article was/.ed that suggested that jets were a big problem for GHGs. But they didn't have a single number in the article. If you simply looked up the numbers, you'd find that jets give off 10% of the GHGs that cars do. That means that even if you reduce the jets emissions to zero, that would be as effective as reducing the cars only 10%. And we can reduce cars by 10%. Easily.
The point is that, like any problem solving exercise, you start with the biggest problem and then work your way down the list. And in this case, cars are a much bigger problems than jets, so you start with the cars.
And now we have an article that suggests we shouldn't improve home energy use because that would somehow stop us from fixing the problem in "most of the world". Once again, not a single number.
As you can see, the United States and China are the problem. A 10% reduction in China is the same as all of Canada, South America and Oceana put together. So if we're going to fix the problem, that's where you start. And the Chinese are perfectly capable of doing this without our help.
The article is bizarre if you think about it. I shouldn't use LED light bulbs because that lets the power company off the hook to solve their problems? Wow, some logic.
> the Hiiggs Boson either doesn't exists or has different properties than the Standard Model predicts
Well he got his wish, in a way.
The SM doesn't predict any particular mass for the Higgs. It doesn't predict masses at all, except in the way that it defines relative masses, sort of. So if the mass of particle A is 1 then B has to be at least 2 for the theory to work, but it doesn't say that A has to be 1, and if it's 0.5 then B can be 1. A number of new theories do predict masses directly, or have relative masses like the SM, but require those relative masses to be different.
Right now the entire field is basically up in the air over how to continue development, whether that be supersymmetry or multiple dimensions. They both require different Higgs mass, one around (going completely on memory here) 114 GeV and the other a little less than 140.
Atlas and CMS both put the mass around 125, which means both are wrong. This is a good thing, because both systems stink.
> What's worth pointing out is that none of these of super-smart people have > any actual experience with putting warheads in mylar ballons
Ummm, yeah they did. The RBIG's report started development of Minuteman's decoy suite.
> Your entire argument essentially boils down to a false appeal to authority.
The world's leading authorities on the topic. I'll take Hans Bethe's word on the topic over what you offer, which is precisely nothing.
> a good decoy (one which is impossible to distinguish from a warhead), essentially > replaces a warhead thus reducing the carrying capacity of your missile
You clearly have no idea what you are talking about.
A credible decoy weighs a few kilos. Launch support adds to that. A W87 is maybe 200 to 300 kilos. It is generally stated that you can include 10 credible decoys for every RV, and that even the most basic ICBMs will produce 10s to 100s of decoys, along with chaff, booster fragments, etc. Thousands of objects per ICBM would be typical.
Which is every ICBM and SLBM in the world has been packed with decoys and chaff starting in the 1960s. It's simple and cheap and capable of defeating even the most elaborate BMDs through the midcourse.
> and ABM missiles are much, much, cheaper than ICBM's
The cost exchange ratio is around 20 in favour of ICBMs.
> neglected the developments of the past half century plus
Right, because the laws of physics changed in the last 50 years.
But whatever, there's a massive amount of literature on the topic that can easily be found in Google, dating from the 1950s right into this year. So all the other readers here can peruse that at their leisure and make up their own mind. This will get you started:
It used some pretty clever techniques to measure perceived differences, rather than theoretical. H.265/HVEC won very slightly at very high definition, and increasingly won as the bandwidth was reduced. VP9 was "competitive" only at the highest quality settings. At lower settings, VP9 did increasingly poorly, until it was worse than H.264/AVC. VP9 outperformed HVEC on a single data point, for all the other 269 data points HVEC was varyingly degrees of better.
A quote says it all:
"Substantial quality improvements of HEVC coding algorithm in relation to AVC and VP9 are visible especially for lower bit-rates."
> which, if you believe it, would imply that a whole bunch of very smart people at Google have spent several years wasting their time.
Or that a whole bunch of very smart people *over the entire planet Earth* collectively outperformed a smaller number of very smart people at Google.
> but moving to EV cars now won't make one jot of difference
Moving to EVs will lower emissions by about one half...
> because the electricity we use to charge them comes from... fossil fuels...because the energy we use to charge them comes from a mixture of sources that are, on average, far less polluting than a gasoline engine:
Moreover, the most fantastical rate that we could possibly make the move to EV's is slower than the rate we're already greening the electrical supply, so EV's will continue to improve over time at a rate gasoline improvements can't match:
Which is really besides the point, because the emissions of most of the industrialized world is already below the point where you're better off with an EV:
> 's just like modern dishwashers; they're far more efficient
I have a brand new Frigidaire dishwasher. It's most efficient cycle, using air drying and "eco mode", uses 22 litres of water, takes 99 minutes to complete, and something like 2 to 3 kWh of power. That is in addition to the gas water heater that supplied the hot water.
I can do that same load of dishes in less than 10 minutes, typically closer to five. I use no electricity to do so, and about 15 to 20 litres of water. Those who use a stoppered sink to rinse will reduce water use significantly.
There are much more efficient models on the market, like the 18" Bosch I had in my last house. However, for north american users at least, the average dishwasher is easy to outperform.
> That won't help until aging hippie hand-wringers stop getting their panties in a twist, > and get out of the way of us building a lot more modern nuclear power plants
The only thing stopping nuclear power is the cost of the plants.
They cost $8/W CAPEX and come in sizes of 900MW and up. Finding someone willing to put up the tens of billions of dollars needed to build a typical multi-unit plant is difficult in a market economy. That is the reason, *the only reason*, that more nukes aren't being built.
But just think about your own argument for a second. Do you really believe that nukes are so horribly supported that the entire industry has been stopped dead by "aging hippie hand-wringers"? If you really believe that, do you actually *want* that apparently utterly incompetent industry building nukes?
Here's actual up to date numbers, turn to page 11:
Nukes have put a very very small dent in the problem, and it grows smaller every year. Meanwhile, NG, wind and solar are putting huge dents in it, every year. The last EIA numbers suggest that renewables will be installed at ten times the rate of nukes, on a power-delivered basis:
While I've long been a critic of all ABM programs, and so should in theory agree with the basis of this post, but this article downright stinks. It is clear the author doesn't really understand any of the technical issues he writes about with feigned authority. The baseball analogy section is particularly laughable, picking apart a dumb offhand statement while utterly missing the entire point of the analogy, and failing to consider the issue that the radar can't possibly do what it claims to anyway.
For those of you interested in all of this, I suggest you read the Wiki article on Nike Zeus. The problems with decoys were well known in 1958, and panel after panel of the super-smart (including nobel laureates) examined the issue in depth and basically said that a good decoy is literally impossible to distinguish from the warhead. Why? Because you can put the warhead in a mylar balloon and launch several similar balloons on nearby trajectories, and that's basically that.
Everyone has been aware of this issue ever since. Nike-X and LOADS were invented to work at much lower altitudes, where the decoys were no longer a factor (they're balloons, they begin to float once they start to re-enter), while the PRESS series attempted to find differences in ionization or other physical effects of the earliest stages of reentry to the same end. Both ultimately failed - Nike-X could be overwhelmed with MIRV for almost zero cost, and PRESS demonstrated that no such measurable difference actually exists.
No amount of engineering can fix this. All you can do is hope that the decoys have bad trajectories or tumble, with the later being of zero use if it's spherical. It is entirely possible that North Korea has bad decoys, but given that the UK built really good ones in the 60s as part of Chevaline, its certainly not a $10 billion bet I'd make. And then there's the killer problem - you deliberately launch the RV on a "bad" trajectory so its not a threat, and then maneuver after the midcourse onto the target. This problem killed Hardsite, and it only had to work over about 10 miles, not 10,000.
I'm not saying that BMD is a bad idea, but everyone should be perfectly aware that any BMD can be penetrated with some degree of ease. The question, as it has been since the 50s, is whether by spending XXX dollars on improving the defense can be offset by spending XXX on better penaids. NK is a poor country so its a question to ponder, but for anyone else the answer is, and always has been, that it's about 20 times cheaper to penetrate the BMD than build it.
> If you can build giant solar arrays in GEO, you can build small ones and attach ion thrusters to them.
Well, that's just putting the cart before the horse isn't it? We have no idea how to do A, so I think you're a little premature claiming "nope"!
Maybe you should tell Don Kessler that we have it all solved. You know, the guy that they named the "Kessler syndrome" after. He's pretty adamant against SPSs: "Some of the most environmentally dangerous activities in space include [...] large structures such as those considered in the late-1970s for building solar power stations in Earth orbit" I've emailed with him recently, he hasn't changed his mind since 2009 when he wrote that. Ask him yourself.
I did the calcs on this with Don's help a few years back. I recall there being something like a 10% chance that every SPS would cause a Kessler syndrome in MEO. I'll dig up the numbers for you.
So think about the *entire universe* of possible technological advances over time. Draw that as a rectangle.
Now think about all of the technical advances within that rectangle that improve solar power collection at any level. Draw a circle to cover that area. Did you do 10% of the rectangle? 20%? Excellent.
Now draw a circle representing all of the advances in the rectangle that improve solar power collection *only in space*. Draw a circle. That circle will be much smaller, and intersect the first one you drew almost entirely. In the sections that don't overlap you basically have three items, more efficient visible light lasers (more than 50% socket to light, to be exact), lightweight space structures, orders of magnitude lower launch costs.
Now throw darts at the wall. See how often you hit that section.
See the problem?
Now for fun, multiply the areas by the amount of money being spent on each of those.
> The second assumption is that any solar power station has to be photovoltaic
I have to be missing something here though, because I recall rectenna size projections being about 60% the size of a PV field of the same peak. Let me dig into this a bit more...
In the meantime, Do The Math digs a little deeper into that: http://physics.ucsd.edu/do-the-math/2012/03/space-based-solar-power/
> Spectrolab rates their space solar panels for 20 years at GEO
This is not the 20% degradation point I use in my article, this is the "totally dead" point. The "totally dead" point for the average solar panel on earth is unknown, because they haven't been in service long enough to know. All we know for sure is that the vast majority of panels installed in 1982 are still working just fine today (and I know examples from the 1970s). Some have suggested the totally dead point for panels on the ground is at about 100 years, although I suspect silver migration and back-rot will reduce that to the 50 year mark.
Interesting notes though: one is that the lifetime in GEO is higher than LEO which is higher than MEO. Given radiation flux is higher as you go up, one might conclude that the main damage mode is debris.
> Your comparison of operating hours neglects that in space you have 36% higher insolation
That is included in the "I" number. If I was simply day/night, then it would be 8765/2 = 4382. But the I is 2300 for the ground based panels, which is taking all of those other effects into consideration.
> cherry-picking a good location is unfair
What, like GEO?:-) Actually it's not that much of a joke, you'll have to move all the comsats out of the way, which would be fun...
But fair enough, point taken. You can use PVWatts to pick another location. Or pick from this list:
> That is true if the efficiency of the panels improve
No, it's true in almost all cases.
Take a cell and put it in space and it will deliver less power. Period. It doesn't make a difference if your launchers get cheaper, or your cells get lighter, delivering less power is delivering less power. Unless your invention makes space launches cost negative dollars, you lose.
1. The panels may get much lighter, till they weigh as much as a sheet of mylar.
Does not help, less power is less power.
But that makes them lighter on the ground too, which lowers their install cost there. And thin cells like this would be perfect for putting in shingles, which makes every residential house and garage a collector.
2. Launch tech improves, and brings the cost of cargo to orbit way down.
Does not help, less power is less power.
3. The tech for transmitting and receiving power through space improves
Now this DOES help. However, this is simply a function of basic radio physics. Google up antenna factor some time. The electronics side of thing is pretty much at the efficiency limit already - I've seen solar inverters with 98% DC to AC conversion efficiency, which is pretty astounding if you think about it.
Then they couldn't be intending "to test the technology in 2018", could they? You need *actual money* to build *actual hardware*.
It was a trial balloon, precisely like this one. Free press for a slow news day.
> That does not change the fact that the math is pretty solid and it would work.
Go right ahead and demonstrate the math in question. Develop from the CAPEX side through to the LCoE. Include OPEX and regulatory loads, if you care to.
Or you could save yourself the trouble and use the spreadsheet I developed. Where should I send it?
> Off the top of my head, I can't see any particularly good reason why a space-based > system should be shorter-lived than a ground-based system.
The reasons are very clearly explained right there and I even linked to the real-world articles I took the numbers from.
>he 'd assumed a similar lifetime for the space-based system
Look at the image at the top of the page. Do you see it? That's Mir's solar panels after about *10 years*. Hubble replaced its panels twice over a period of 13 years. Space absolutely sucks for solar panels.
> Arguably, a space-based system will last less time than a ground-based system.
There's no "arguing" involved, we've had panels in space and on the ground for decades and we know very well how long these things last.
Click the links, it's not like they're going to bite you.
> You've ignored the atmospheric losses suffered by ground-based systems -- clouds, dust, the opacity of air
No, that's what the insolation number takes care of, I. There's a link right in the article to where this number came from, you can click it, type in your location, and find the number yourself. As I mentioned earlier, it definitely includes "clouds, dust, the opacity of air", as well as geometric pointing errors, day/night cycle, and even reflection off snow and dirt on the panels.
> you're also being much more generous in estimating the potential lifetime of ground-based systems
As the links at the bottom of the article note, these are real-world numbers as measured on real systems that have been in the field for decades. If you have better numbers, fine...
PROVIDE YOUR REFERENCES AND DO THE MATH YOURSELF!
> though that depends on how much we value land taken up by solar arrays
Or rectennas. You recall that SPSS's have a downlink portion, right?
No, they don't. The project died, if it ever existed in any meaningful form, because it never had a budget.
It was a trial balloon sent up by the space industry to create demand for new rockets. That's the only reason this idea keeps getting floated, as an excuse to make more rockets or heavy launchers.
> For example I do not see why Tg is different for ground based versus space based systems
The reason should have been explained, which I now realize has not been. Basically it *should* be easier to convert constant "insolation" from the rectenna to AC power than doing the same for variable inputs from the PV panels.
But you know what, you're absolutely right. It has basically no effect on the outcome, and simply confuses matters. I'll update the article and leave a note at the bottom.
Actually I should do that anyway, because NREL *finally* updated the derate in PVWatts from 0.77, which was hopelessly outdated, to 0.86(4?) which is more in line with modern inverters.
> and why it so not eliminated as per the E term
Yes, an update is in order, it would definitely improve it in this fashion. That should have been clear to me when I was writing it. Thanks!
> he leaves out the fact that a space based PV system operates 24/7 with continuous output compared to an earth > based system that has to deal with the vagaries of weather and that pesky thing called "night".
No, actually, I didn't. That is encoded in the insolation number. PVWatts considers day/night, clouds, reflections off snow, dirt on the panels, and all sorts of other factors in its calculations. It's totally crescent fresh, check it out for your own location:
> It certainly won't happen until we get better tech, but never say "never".
You may have missed the point of the linked article. If you improve the tech of the panels, then the relative advantage of mounting them on the ground *improves*.
> But TFA is about some 93 year old retired Chinese geezer "mulling" the idea
Geez, I totally missed that.
It always is, BTW. The entire space power group is made up almost entirely of retired astronauts and rocket engineers. That and the hangers-on like the National Space Society and such. I have yet to meet a single person from the power industry that is even marginally involved.
Slashdot Mirror
Now we can get useless results twice as fast!
For those of you unfamiliar with the history:
https://en.wikipedia.org/wiki/LASNEX
Why does anyone even think this would be a problem?
Did the Homo Erectus walking from Africa to Asia in small family groups often murder each other?
Did the Polynesian cross-pacific crews commit suicide en-route?
Did the native americans all go crazy while crossing the land bridge on the way to becoming native americans?
Does this ever happen on submarines?
NASA has been worried about isolation, sex, and infighting since the 60s. Maybe they should stop asking themselves what will happen, a large group of nerds probably isn't the first place you go to find out about these topics.
> Even lead-acid batteries are quite small.
Oh god no. According to the EIA average US house uses about 30 kWh a day.
Lead-acid batteries do not like to be run down past 50%, and if you want them to last even a few years, 65% is the minimum. So if you want one day of storage, you'll need 75 kWh worth of batteries. A 75 kWh lead-acid battery bank would fill a bedroom. That is not small.
Li-ion has two to three times the energy density. It can also be repeatedly drawn down to 20%, and that number is improving. So for that same 30 kWh home, you would need about 40 kWh of li-ion, so the total battery bank size would be at *least* 4 times smaller, about the size of a small fridge.
But what you really need to do is just improve the homes. Last year I was burning about 15 kWh a day on average, about 1/2 the average US home, and significantly less than the 25 kWh average for Canada. I replaced all the light bulbs with LEDs and upgraded my computer (which uses less energy), and since then my average is 11 kWh. With li-ion, that would be a beer fridge.
A while back an article was /.ed that suggested that jets were a big problem for GHGs. But they didn't have a single number in the article. If you simply looked up the numbers, you'd find that jets give off 10% of the GHGs that cars do. That means that even if you reduce the jets emissions to zero, that would be as effective as reducing the cars only 10%. And we can reduce cars by 10%. Easily.
The point is that, like any problem solving exercise, you start with the biggest problem and then work your way down the list. And in this case, cars are a much bigger problems than jets, so you start with the cars.
And now we have an article that suggests we shouldn't improve home energy use because that would somehow stop us from fixing the problem in "most of the world". Once again, not a single number.
Well here's some numbers:
http://www.epa.gov/climatechange/science/indicators/ghg/global-ghg-emissions.html
As you can see, the United States and China are the problem. A 10% reduction in China is the same as all of Canada, South America and Oceana put together. So if we're going to fix the problem, that's where you start. And the Chinese are perfectly capable of doing this without our help.
The article is bizarre if you think about it. I shouldn't use LED light bulbs because that lets the power company off the hook to solve their problems? Wow, some logic.
> the Hiiggs Boson either doesn't exists or has different properties than the Standard Model predicts
Well he got his wish, in a way.
The SM doesn't predict any particular mass for the Higgs. It doesn't predict masses at all, except in the way that it defines relative masses, sort of. So if the mass of particle A is 1 then B has to be at least 2 for the theory to work, but it doesn't say that A has to be 1, and if it's 0.5 then B can be 1. A number of new theories do predict masses directly, or have relative masses like the SM, but require those relative masses to be different.
Right now the entire field is basically up in the air over how to continue development, whether that be supersymmetry or multiple dimensions. They both require different Higgs mass, one around (going completely on memory here) 114 GeV and the other a little less than 140.
Atlas and CMS both put the mass around 125, which means both are wrong. This is a good thing, because both systems stink.
> pretty sure being right allows us to advance more quickly
Definitely not. The exact opposite is much closer to the truth.
> What's worth pointing out is that none of these of super-smart people have
> any actual experience with putting warheads in mylar ballons
Ummm, yeah they did. The RBIG's report started development of Minuteman's decoy suite.
> Your entire argument essentially boils down to a false appeal to authority.
The world's leading authorities on the topic. I'll take Hans Bethe's word on the topic over what you offer, which is precisely nothing.
> a good decoy (one which is impossible to distinguish from a warhead), essentially
> replaces a warhead thus reducing the carrying capacity of your missile
You clearly have no idea what you are talking about.
A credible decoy weighs a few kilos. Launch support adds to that. A W87 is maybe 200 to 300 kilos. It is generally stated that you can include 10 credible decoys for every RV, and that even the most basic ICBMs will produce 10s to 100s of decoys, along with chaff, booster fragments, etc. Thousands of objects per ICBM would be typical.
Which is every ICBM and SLBM in the world has been packed with decoys and chaff starting in the 1960s. It's simple and cheap and capable of defeating even the most elaborate BMDs through the midcourse.
> and ABM missiles are much, much, cheaper than ICBM's
The cost exchange ratio is around 20 in favour of ICBMs.
> neglected the developments of the past half century plus
Right, because the laws of physics changed in the last 50 years.
But whatever, there's a massive amount of literature on the topic that can easily be found in Google, dating from the 1950s right into this year. So all the other readers here can peruse that at their leisure and make up their own mind. This will get you started:
https://books.google.ca/books?id=jsH_AwAAQBAJ
> Any citations on this?
There's lots. I think the most trustworthy would be this one:
http://infoscience.epfl.ch/record/200925/files/article-vp9-submited-v2.pdf
It used some pretty clever techniques to measure perceived differences, rather than theoretical. H.265/HVEC won very slightly at very high definition, and increasingly won as the bandwidth was reduced. VP9 was "competitive" only at the highest quality settings. At lower settings, VP9 did increasingly poorly, until it was worse than H.264/AVC. VP9 outperformed HVEC on a single data point, for all the other 269 data points HVEC was varyingly degrees of better.
A quote says it all:
"Substantial quality improvements of HEVC coding algorithm in relation to AVC and VP9 are visible especially for lower bit-rates."
> which, if you believe it, would imply that a whole bunch of very smart people at Google have spent several years wasting their time.
Or that a whole bunch of very smart people *over the entire planet Earth* collectively outperformed a smaller number of very smart people at Google.
> Nope, not even close
Here we go, this should be good...
> but moving to EV cars now won't make one jot of difference
Moving to EVs will lower emissions by about one half...
> because the electricity we use to charge them comes from... fossil fuels ...because the energy we use to charge them comes from a mixture of sources that are, on average, far less polluting than a gasoline engine:
https://matter2energy.wordpress.com/2013/02/22/wells-to-wheels-electric-car-efficiency/
Moreover, the most fantastical rate that we could possibly make the move to EV's is slower than the rate we're already greening the electrical supply, so EV's will continue to improve over time at a rate gasoline improvements can't match:
https://matter2energy.wordpress.com/2014/09/16/future-grid-energy-in-the-not-so-distance/
Which is really besides the point, because the emissions of most of the industrialized world is already below the point where you're better off with an EV:
https://matter2energy.wordpress.com/2015/04/01/electric-cars-and-carbon-intensity/
And all that we really need is cheaper batteries, which we should be crossing gasoline numbers around 2020:
https://matter2energy.wordpress.com/2015/04/05/ev-battery-prices-falling-rapidly/
> EV just to claim green credentials is largely an illusion
A statement that you might believe if you've never really looked at the issue or run a single number to back up your prejudices.
> Most of those things (particularly HVAC) can be done with electricity
And for most, georeturn HVAC is far, far more energy efficient than any other source.
It's expensive when everyone has their own tubing, but it seems to me there's a lot of municipal greywater that could be serving this purpose.
> 's just like modern dishwashers; they're far more efficient
I have a brand new Frigidaire dishwasher. It's most efficient cycle, using air drying and "eco mode", uses 22 litres of water, takes 99 minutes to complete, and something like 2 to 3 kWh of power. That is in addition to the gas water heater that supplied the hot water.
I can do that same load of dishes in less than 10 minutes, typically closer to five. I use no electricity to do so, and about 15 to 20 litres of water. Those who use a stoppered sink to rinse will reduce water use significantly.
There are much more efficient models on the market, like the 18" Bosch I had in my last house. However, for north american users at least, the average dishwasher is easy to outperform.
> That won't help until aging hippie hand-wringers stop getting their panties in a twist,
> and get out of the way of us building a lot more modern nuclear power plants
The only thing stopping nuclear power is the cost of the plants.
They cost $8/W CAPEX and come in sizes of 900MW and up. Finding someone willing to put up the tens of billions of dollars needed to build a typical multi-unit plant is difficult in a market economy. That is the reason, *the only reason*, that more nukes aren't being built.
But just think about your own argument for a second. Do you really believe that nukes are so horribly supported that the entire industry has been stopped dead by "aging hippie hand-wringers"? If you really believe that, do you actually *want* that apparently utterly incompetent industry building nukes?
Here's actual up to date numbers, turn to page 11:
http://www.lazard.com/PDF/Levelized%20Cost%20of%20Energy%20-%20Version%208.0.pdf
> Nothing else will even put a dent in it.
Nukes have put a very very small dent in the problem, and it grows smaller every year. Meanwhile, NG, wind and solar are putting huge dents in it, every year. The last EIA numbers suggest that renewables will be installed at ten times the rate of nukes, on a power-delivered basis:
http://www.eia.gov/electricity/monthly/update/
http://www.eia.gov/todayinenergy/detail.cfm?id=20492
Nukes are dead, they committed suicide.
While I've long been a critic of all ABM programs, and so should in theory agree with the basis of this post, but this article downright stinks. It is clear the author doesn't really understand any of the technical issues he writes about with feigned authority. The baseball analogy section is particularly laughable, picking apart a dumb offhand statement while utterly missing the entire point of the analogy, and failing to consider the issue that the radar can't possibly do what it claims to anyway.
For those of you interested in all of this, I suggest you read the Wiki article on Nike Zeus. The problems with decoys were well known in 1958, and panel after panel of the super-smart (including nobel laureates) examined the issue in depth and basically said that a good decoy is literally impossible to distinguish from the warhead. Why? Because you can put the warhead in a mylar balloon and launch several similar balloons on nearby trajectories, and that's basically that.
Everyone has been aware of this issue ever since. Nike-X and LOADS were invented to work at much lower altitudes, where the decoys were no longer a factor (they're balloons, they begin to float once they start to re-enter), while the PRESS series attempted to find differences in ionization or other physical effects of the earliest stages of reentry to the same end. Both ultimately failed - Nike-X could be overwhelmed with MIRV for almost zero cost, and PRESS demonstrated that no such measurable difference actually exists.
No amount of engineering can fix this. All you can do is hope that the decoys have bad trajectories or tumble, with the later being of zero use if it's spherical. It is entirely possible that North Korea has bad decoys, but given that the UK built really good ones in the 60s as part of Chevaline, its certainly not a $10 billion bet I'd make. And then there's the killer problem - you deliberately launch the RV on a "bad" trajectory so its not a threat, and then maneuver after the midcourse onto the target. This problem killed Hardsite, and it only had to work over about 10 miles, not 10,000.
I'm not saying that BMD is a bad idea, but everyone should be perfectly aware that any BMD can be penetrated with some degree of ease. The question, as it has been since the 50s, is whether by spending XXX dollars on improving the defense can be offset by spending XXX on better penaids. NK is a poor country so its a question to ponder, but for anyone else the answer is, and always has been, that it's about 20 times cheaper to penetrate the BMD than build it.
"it can now play silky smooth 720p with VP9.""
Really? This is their selling point.
It's dead, Jim. Time to join Buzz, Gears and the others.
> If you can build giant solar arrays in GEO, you can build small ones and attach ion thrusters to them.
Well, that's just putting the cart before the horse isn't it? We have no idea how to do A, so I think you're a little premature claiming "nope"!
Maybe you should tell Don Kessler that we have it all solved. You know, the guy that they named the "Kessler syndrome" after. He's pretty adamant against SPSs: "Some of the most environmentally dangerous activities in space include [...] large structures such as those considered in the late-1970s for building solar power stations in Earth orbit" I've emailed with him recently, he hasn't changed his mind since 2009 when he wrote that. Ask him yourself.
I did the calcs on this with Don's help a few years back. I recall there being something like a 10% chance that every SPS would cause a Kessler syndrome in MEO. I'll dig up the numbers for you.
> The first one is no technological progress
So think about the *entire universe* of possible technological advances over time. Draw that as a rectangle.
Now think about all of the technical advances within that rectangle that improve solar power collection at any level. Draw a circle to cover that area. Did you do 10% of the rectangle? 20%? Excellent.
Now draw a circle representing all of the advances in the rectangle that improve solar power collection *only in space*. Draw a circle. That circle will be much smaller, and intersect the first one you drew almost entirely. In the sections that don't overlap you basically have three items, more efficient visible light lasers (more than 50% socket to light, to be exact), lightweight space structures, orders of magnitude lower launch costs.
Now throw darts at the wall. See how often you hit that section.
See the problem?
Now for fun, multiply the areas by the amount of money being spent on each of those.
> The second assumption is that any solar power station has to be photovoltaic
Read my last sentence above a second time.
> Wouldn't that make its size not grow with the size of the array of solar panels in space
Ahhh, well that depends on how high you're allowed to push the energy density of the beam.
Current international limits are 50 W/m^2. The sun at noon is 1000 W/m^2, so by that standard the rectenna is going to be very large indeed.
I seem to recall projections on beam energies around 1250 W/m^2, but now I can't seem to find anything over 40 W/m^2:
http://www.nss.org/settlement/ssp/spacepower/spacepower01.html
http://arxiv.org/abs/1401.1779
I have to be missing something here though, because I recall rectenna size projections being about 60% the size of a PV field of the same peak. Let me dig into this a bit more...
In the meantime, Do The Math digs a little deeper into that: http://physics.ucsd.edu/do-the-math/2012/03/space-based-solar-power/
> Spectrolab rates their space solar panels for 20 years at GEO
This is not the 20% degradation point I use in my article, this is the "totally dead" point. The "totally dead" point for the average solar panel on earth is unknown, because they haven't been in service long enough to know. All we know for sure is that the vast majority of panels installed in 1982 are still working just fine today (and I know examples from the 1970s). Some have suggested the totally dead point for panels on the ground is at about 100 years, although I suspect silver migration and back-rot will reduce that to the 50 year mark.
Interesting notes though: one is that the lifetime in GEO is higher than LEO which is higher than MEO. Given radiation flux is higher as you go up, one might conclude that the main damage mode is debris.
> Your comparison of operating hours neglects that in space you have 36% higher insolation
That is included in the "I" number. If I was simply day/night, then it would be 8765/2 = 4382. But the I is 2300 for the ground based panels, which is taking all of those other effects into consideration.
> cherry-picking a good location is unfair
What, like GEO? :-) Actually it's not that much of a joke, you'll have to move all the comsats out of the way, which would be fun...
But fair enough, point taken. You can use PVWatts to pick another location. Or pick from this list:
Toronto: 1,840
Calgary: 2,400 (wow!)
London: 1,302 (yikes, rainy london indeed!)
Moscow: 1,259
Looks like the break-even is around Moscow. Remember though, that's just in energy terms... in economic terms, enjoy!
> That is true if the efficiency of the panels improve
No, it's true in almost all cases.
Take a cell and put it in space and it will deliver less power. Period. It doesn't make a difference if your launchers get cheaper, or your cells get lighter, delivering less power is delivering less power. Unless your invention makes space launches cost negative dollars, you lose.
1. The panels may get much lighter, till they weigh as much as a sheet of mylar.
Does not help, less power is less power.
But that makes them lighter on the ground too, which lowers their install cost there. And thin cells like this would be perfect for putting in shingles, which makes every residential house and garage a collector.
2. Launch tech improves, and brings the cost of cargo to orbit way down.
Does not help, less power is less power.
3. The tech for transmitting and receiving power through space improves
Now this DOES help. However, this is simply a function of basic radio physics. Google up antenna factor some time. The electronics side of thing is pretty much at the efficiency limit already - I've seen solar inverters with 98% DC to AC conversion efficiency, which is pretty astounding if you think about it.
> ofc it had no budget.
Then they couldn't be intending "to test the technology in 2018", could they? You need *actual money* to build *actual hardware*.
It was a trial balloon, precisely like this one. Free press for a slow news day.
> That does not change the fact that the math is pretty solid and it would work.
Go right ahead and demonstrate the math in question. Develop from the CAPEX side through to the LCoE. Include OPEX and regulatory loads, if you care to.
Or you could save yourself the trouble and use the spreadsheet I developed. Where should I send it?
> Off the top of my head, I can't see any particularly good reason why a space-based
> system should be shorter-lived than a ground-based system.
The reasons are very clearly explained right there and I even linked to the real-world articles I took the numbers from.
>he 'd assumed a similar lifetime for the space-based system
Look at the image at the top of the page. Do you see it? That's Mir's solar panels after about *10 years*. Hubble replaced its panels twice over a period of 13 years. Space absolutely sucks for solar panels.
> Arguably, a space-based system will last less time than a ground-based system.
There's no "arguing" involved, we've had panels in space and on the ground for decades and we know very well how long these things last.
Click the links, it's not like they're going to bite you.
> You've ignored the atmospheric losses suffered by ground-based systems -- clouds, dust, the opacity of air
No, that's what the insolation number takes care of, I. There's a link right in the article to where this number came from, you can click it, type in your location, and find the number yourself. As I mentioned earlier, it definitely includes "clouds, dust, the opacity of air", as well as geometric pointing errors, day/night cycle, and even reflection off snow and dirt on the panels.
> you're also being much more generous in estimating the potential lifetime of ground-based systems
As the links at the bottom of the article note, these are real-world numbers as measured on real systems that have been in the field for decades. If you have better numbers, fine...
PROVIDE YOUR REFERENCES AND DO THE MATH YOURSELF!
> though that depends on how much we value land taken up by solar arrays
Or rectennas. You recall that SPSS's have a downlink portion, right?
> JAXA intends to test the technology in 2018
No, they don't. The project died, if it ever existed in any meaningful form, because it never had a budget.
It was a trial balloon sent up by the space industry to create demand for new rockets. That's the only reason this idea keeps getting floated, as an excuse to make more rockets or heavy launchers.
> For example I do not see why Tg is different for ground based versus space based systems
The reason should have been explained, which I now realize has not been. Basically it *should* be easier to convert constant "insolation" from the rectenna to AC power than doing the same for variable inputs from the PV panels.
But you know what, you're absolutely right. It has basically no effect on the outcome, and simply confuses matters. I'll update the article and leave a note at the bottom.
Actually I should do that anyway, because NREL *finally* updated the derate in PVWatts from 0.77, which was hopelessly outdated, to 0.86(4?) which is more in line with modern inverters.
> and why it so not eliminated as per the E term
Yes, an update is in order, it would definitely improve it in this fashion. That should have been clear to me when I was writing it. Thanks!
> he leaves out the fact that a space based PV system operates 24/7 with continuous output compared to an earth
> based system that has to deal with the vagaries of weather and that pesky thing called "night".
No, actually, I didn't. That is encoded in the insolation number. PVWatts considers day/night, clouds, reflections off snow, dirt on the panels, and all sorts of other factors in its calculations. It's totally crescent fresh, check it out for your own location:
http://pvwatts.nrel.gov
> It certainly won't happen until we get better tech, but never say "never".
You may have missed the point of the linked article. If you improve the tech of the panels, then the relative advantage of mounting them on the ground *improves*.
> But TFA is about some 93 year old retired Chinese geezer "mulling" the idea
Geez, I totally missed that.
It always is, BTW. The entire space power group is made up almost entirely of retired astronauts and rocket engineers. That and the hangers-on like the National Space Society and such. I have yet to meet a single person from the power industry that is even marginally involved.