While I certainly would be a little leery of some sources, at least I have provided some. Would you care to share your sources?
Unless that newsletter is your source... in which case I suggest you do a little more research. I will not claim to be any kind of expert but at least I have studied Stirling engines to a degree and even constructed a few models. At least the numbers I put forth are not *completely* out of my ass...
So how about some actual math? Please try to follow along...
Peak output: 25kW (Not 2kW as in your half-assed example)
Dish radius: 37 feet. (11.2 meters)
Solar insulation: 1000 watts/sq. meter (This is a good number since Southern California is considered a "high insolation" area)
So the area of the dish is 3.14*((11.2)^2)/4 = 98.4704 sq.meters. Let's round this down to 95 since it's not a solid collecting surface.
That's 95kW input to the engine. We get 25kW out as electrical power.
(25/95) = 26% efficiency overall.
I refer you to my previous post where I said "25% overall efficiency". Well what do ya know... we arrived at the same number using two completely different methods.
May I offer a possible explanation about the 10% efficiency your as-yet-uncited sources claim? Their temperature gradients were nowhere near 700K, they did not operate at the 1000+ PSI pressures using hydrogen gas, and/or they were very small (tabletop) devices. If any or all of these three were the case then I'm not that surprised their efficiencies sucked.
And you still did not touch upon all the other assertions in your original post that I called bullshit on. =Smidge=
I've built a 6' diameter parabolic dish out of plywood and aluminum flashing for less than US$200. Granted the focus wasn't all that great, but I did get temperatures in excess of 800F out of it. - on a New York February afternoon!
The rest of the equipment: heat collector at the focus, flexible piping, insulation, pipes, evaporators, heat sinks, pumps, working fluid, turbines, gears, cogs, lubricants, generators, buildings, staff, land
What do you need all that stuff for?
With the exception of land (which you will need a lot of but it's all desert and not suited for much else) and a minimal staff, none of that junk is required.
The Stirling cycle runs at 10% efficiency. { Note: most Stirling engines are about 5x less efficient that this}.
This is a little ambiguous. The theoretical Stirling engine can achieve the ideal Carnot efficiency. Real Stirlings can reach 50 percent of this maximum theoretical value.
With a ambient (sink) temperature of, say, 110F (316K) and a temperature of 1400F (1033K - Actually a conservative estimate) our Carnot efficiency is 69.4%. A real high-end Stirling can reach 50% of that, or nearly 35% thermal. After you generate the electricity you are *still* looking at 25% overall efficiency or better.
All that stuff cleans and maintains itself at no cost.
Practically would! If a crew of 3 guys can take a hose truck and rinse the dust off the mirrors of each dish in ~15min, they can do about 30 dishes per day. Each dish would probably only need to be washed once a month, so 30*30 = 900 dishes a month. You'd need 23 crews of 3 men each to maintain 20,000 dishes, or 67 people. A 500MW coal plant would employ about 100. (Guestimated from here) Moreover, the people running a coal plant would have to be skilled to maintain the high pressure steam equipment, which means they would cost more. You would not need special training and licensing to operate a hose truck.
As for the Stirling gen sets themselves, they are hermetically sealed and virtually maintenance free. You can contract out any service that might be required rather than having your own staff. In fact, I would think SES would offer a nice warranty that includes service, so if one does go down simply replace it with a spare unit (They are small and modular, you know) and send them back for service.
The tracking systems are also fairly low maintenance and could be contracted out.
So in light of the above, you may wish to revisit your calculations.
They make a breakthrough and develop an efficient Stiring regenerator, which is simultaneously long and short, conductive and insulating. See : www.tinaja.com/glib/muse116.pdf
So you based your argument on three sentences (one copied almost verbatim) from a journal that seems to deal mostly with electronics? Brilliant. You, sir, seem woefully uninformed about how Stirling engines operate. I will grant you that the regenerator is perhaps the biggest hang up when it comes to design, but by no means is it impossible to create. What you are tying to do is make a medium that stores and rejects heat quickly ("highly conductive") with minimal internal volume ("long and thin") and low pressure loss for gas flow ("short and fat") and does not create a thermal short ("highly insulating"). In practice, a stack of fine mesh stainless steel screens works quite well. I have also read storied about people stuffing the passages in the engine with brass wool to great effect. =Smidge=
Well the problem is hydrocarbons contain a lot of energy, so what made all that energy decide to concentrate itself like that? There had to have been some driving process that took a very large amount of energy and converted it into a slightly smaller but more concentrated form of oil. Plants fit this bill very nicely, since they take solar energy and convert it into more concentrated, carbon based forms.
Also, processes like Thermal Depolymerization demonstrate that biological material such as plant and animal matter can be turned into hydrocarbon oil with heat and pressure in a relatively short time.
Both are very compelling arguments for bio-based oil.
What other theories are there? (Honest question) =Smidge=
Stirlings really do work. The biggest problem is getting them to produce decent amounts of power.
They generally use exotic materials and hermetically sealed, unlubricated crackcases to boost the pressure of the working gas to thousands of PSI (the stirling cycle is completely closed). Usually hydrogen is the gas of choice, but methane and helium are also used.
But you can build a working model out of old tin cans if you were so inclined. Mechanically, the simplest stirling cycle engine has only two moving parts!
If you ever have something shipped, including mail order that you pay S&H for, via UPS you're paying for it (and all the other people who did the same) through increased shipping charges. UPS takes the loss and makes it up through their prices. =Smidge=
Well maintained vehichles and well maintained roads...
Maving experienced a blowout at 85MPH, I can assure you that you have pretty good control over your vehicle.. just don't expect to take any tight turns and leave plenty of room for braking! Control gets difficult once you slow down.
Similarly, at higher speeds you would need a HUGE pothole to have it effect you. Something an inch or two deep and a foot wide will barely be felt. =Smidge=
Based on this, we can take a huge bite out of that 32.8% publication cost. Make it 15%, let's say, since there will still plenty of other expenses to cover. You are not running printing presses or buying ink/paper anymore... storage is also a non-issue, and a great cost since books need to be stored in climate controlled conditions. (So do servers, I suppose, but not on warehouse scales)
The 15.6% "marketing costs" isn't broken out, but it does mention cost of free copies given out to professors. So that can probably be reduced a little bit but I won't guess at how much.
I won't touch anything dealing with the college store since that's not a cost the publisher can do anything about, although there would definitely be savings on that end.
The 10.2% general is also interesting. It's not clear from this what taxes are being paid.
Not that I was expecting even this much detail of a breakdown, of course.
But from this, let's say the publisher cuts costs by 15% instantly just from materials and probably another 10% from all the other places*. Do you think this savings will make its way to the student?
(*I'm sure this would require at least some fundamental change in the way the publisher operates, so that would take some time to realize if it ever is) =Smidge=
I would like to know how you can assert that "the upfront costs 'U' are fairly high and run in the thousands for amature(sic) books and much higher for more proffesional(sic) books that are generally used in colleges." Do you have actual figures?
I honestly can not produce any real numbers as to how much the author's costs are or how many copied a textbook typically sells, but I find it easy to believe that the cost per book is not a substantial part (>10%) of the sticker price. If you could produce some numbers I'd appreciate the information.
If the publisher expects to sell 20,000 copies, (Number of copies taken from an example here, assuming first year cost recovery only) then if the $80 book still carries say $60 worth of "U" costs (Because R is essentially 0 for electronic formats) then that's a total of $1.2M paid for the production of the book. Any publisher that blows $1.2M putting a book together probably needs to be audited by the feds. Plus, that's only $400k in profit.
So how much does a publisher buy the rights to a book for? You are asserting that it's relatively high, so please provide a source. =Smidge=
Explain, please, how the introduction of this DRM e-book diminishes or eliminates availability of the following:
First, let us not try to gauge any impact on existing media, but rather the future of media if this becomes the norm.
- libraries, which are generally cost-free to the user, can provide access to books, magazines, technical/medical journals, and the Internet
How do you lend someone a DRM'd eBook without defeating the purpose of DRM? How do you handle licensing issues when before the library could only lend to as many people as it had physical copies? If you restrict the total number of copies, what happens to people who don't "return" the DRM'd copy? etc etc
bookstores selling inexpensive new books (e.g. paperback)
Again, this is current way of doing things. The new way would be via eBooks. Publishers are not likely to reduce the cost of their $100 book all that much regardless of the fact that it costs nothing to reproduce, plus there will be DRM which I'm sure they will add to the price even though it costs them nothing extra.
bookstores selling used books, often at a small fraction of the original price
With eBooks there is no such thing as "used" anymore. eBooks will not wear out like a physical book will. All copies are new copies even if the DRM license is somehow recycled to a new user.
information available on reputable web sites (for access issues see Libraries)
That information is not a replacement for a textbook, unless the book author or publisher has created an online version. Web sites are great supplements, but when the professor tells you to read chapter 5 for the test next week a website isn't going to help.
Not that DRM'd eBooks make any difference in that respect, so I'm not entirely sure why you brought it up.
People that want to learn will find a way. Whether that learning takes place inside or outside the halls of academia depends on the individual.
Ah, that's why. Too bad universities also offer things you can't find easily on the "outside" - like access to laboratories, materials and other facilities and equipment, direct communication with people knowledgeable in the field (professors, lab technicians), and accreditation recognised by potential employers (or clients if you plan to work for yourself).
No one is required to buy the e-books, so your classist argument falls rather flat.
No one is required to buy the eBooks... yet. Or rather, they are still offering the printed versions because they want to see if they can get away with all electronic versions without too many headaches. If they can sell you a printed book for $100 (With like $70 profit) they will gladly sell you a $80 eBook for nearly $80 profit, since cost of duplication and distribution is virtually nil. You'll buy it because you'll save $20.
I wouldn't be all that surprised if they just closed the book stores and sold you the eBooks directly, adding the cost to your tuition. ("Sure the tuition is more expensive, but at least I get free* eBooks!")
It's not really a game. Minimally interactive demo really...
Arrow/WASD keys control steering and accel/brake, but the car drives itself to stay on the road so you really can't steer. 1-4 selects a road/scene, C adds 8 cars, K toggles palette rotation.
With palette rotation this would almost make a good screensaver... =Smidge=
Actually, yes. It might not be camera parts, but they typically have a (very small) section where you can buy overpriced and shit quality parts for electronics projects, as well as things like cable connectors and oddball batteries.
But 99% of all the places I've been to (That is, 99% of each location - 100% of locations!) have been dedicated to selling satellite TV, stereo equipment and toys, with a sales staff that has no training or experience other than selling you cell phones. =Smdige=
35mm film cameras outsold Wet Plate Photography kits by a ratio of over 1,000,000:1
The moral: If you don't feel digital cameras are as high a quality as film cameras, you really have to admit they come pretty close and will only get better. Even if they are not-quite-as-good-yet the extra flexibility and convenience more than makes up for it.
pff Survivors in Toronto's crash last week 100% survivors in NASA's last crash 0%...
Not to downplay the survival rate of that particular crash, but let's put things into persepctive:
Flight 358 had just touched down and failed to stop before running off the runway and into a ditch at less than 90 MPH.
Columbia was travelling at roughtly 18,000 MPH when the heat basically melted the craft, causing it to disintegrate.
That's a pretty rough comparison. Having said that, how many commercial aircraft have exploded mid-flight and had any survivors? And none of them were going 18,000 MPH! =Smidge=
The colder your source (Outside temperature) the less efficient they become. If you live somewhere where it gets to be really cold outside, the unit will not be able to pull any heat from the air. In the southern New York climate region where I live, all the heat pumps I've ever seen needed electric heat to make up the difference. (And it doesn't get that cold here!)
Just look at the equation: Thot / (Thot-Tcold)
As Tcold gets closer to 0, (Thot-Tcold) gets bigger and your COP gets smaller.
In practice, you reach an outside temperature where the cycle your heat pump uses fails. For example, a heat pump that uses a phase change refrigerant will not be able to "boil" the refrigerant using the outside air because the compressor can only lower the pressure so much. Once you reach that point you can actually damage the unit by trying to run it.
And I want to kick the guy who wrote that article:)
So anyway... for the general case, straight electric heat will always be a dependable heat source regardless of temperature... unless it's so cold your heating element becomes superconducting! =Smidge=
Where else does the waste, lower efficiency go? It has to come from somewhere and go somewhere.
Heat. Only it's heat where it isn't that useful to you... like as latent heat in the humidity you're generating and higher wavelengths (visible/near visible light).
Yes, making heat can be 100% efficient, but it isn't always that way depending on how you want to use the heat. In this case, an electric IR heater would probably do a better job heating the space and a flourecent/LED lamp would do a MUCH better job creating light if those are your goals. =Smidge=
And what do you do with the sunlight? Convert it into electricity...
Electricity is the "highest quality" power source we can get. Easily stored (batteries, capacitors), transported (wires, EMF), modified (transformers), easily converted into other forms of energy with outstanding efficiency compared to other forms, and in itself completely nonpolluting.
So let's piss away a good portion of the energy we have as electricity by making, storing and distributing Hydrogen!
And Nuclear, while very good and useful, is not renewable and extremely polluting, though thankfully not in the same quantities as traditional power sources like coal... =Smidge=
Cos if it takes more energy to split the water than the split water produces in heat output...
By definition, at best you'll break even. Unfortunately you will lose some energy to entropy, so there is a net loss. Remember: Every time energy changes form, there is loss. The "hydrogen economy" is bunk because you need to make at least two extaenergy conversions (Form hydrogen and burn hydrogen), but does not address where the energy comes from to begin with.
Anyway, if you want heat and light you are better off using the electricity for electric resistance heaters and lightbulbs instead of generating hydrogen with it. MUCH more efficient. =Smidge=
Slashdot Mirror
While I certainly would be a little leery of some sources, at least I have provided some. Would you care to share your sources?
Unless that newsletter is your source... in which case I suggest you do a little more research. I will not claim to be any kind of expert but at least I have studied Stirling engines to a degree and even constructed a few models. At least the numbers I put forth are not *completely* out of my ass...
So how about some actual math? Please try to follow along...
Peak output: 25kW (Not 2kW as in your half-assed example)
Dish radius: 37 feet. (11.2 meters)
Solar insulation: 1000 watts/sq. meter (This is a good number since Southern California is considered a "high insolation" area)
So the area of the dish is 3.14*((11.2)^2)/4 = 98.4704 sq.meters. Let's round this down to 95 since it's not a solid collecting surface.
That's 95kW input to the engine. We get 25kW out as electrical power.
(25/95) = 26% efficiency overall.
I refer you to my previous post where I said "25% overall efficiency". Well what do ya know... we arrived at the same number using two completely different methods.
May I offer a possible explanation about the 10% efficiency your as-yet-uncited sources claim? Their temperature gradients were nowhere near 700K, they did not operate at the 1000+ PSI pressures using hydrogen gas, and/or they were very small (tabletop) devices. If any or all of these three were the case then I'm not that surprised their efficiencies sucked.
And you still did not touch upon all the other assertions in your original post that I called bullshit on.
=Smidge=
I've built a 6' diameter parabolic dish out of plywood and aluminum flashing for less than US$200. Granted the focus wasn't all that great, but I did get temperatures in excess of 800F out of it. - on a New York February afternoon!
=Smidge=
The rest of the equipment: heat collector at the focus, flexible piping, insulation, pipes, evaporators, heat sinks, pumps, working fluid, turbines, gears, cogs, lubricants, generators, buildings, staff, land
What do you need all that stuff for?
With the exception of land (which you will need a lot of but it's all desert and not suited for much else) and a minimal staff, none of that junk is required.
The Stirling cycle runs at 10% efficiency. { Note: most Stirling engines are about 5x less efficient that this}.
This is a little ambiguous. The theoretical Stirling engine can achieve the ideal Carnot efficiency. Real Stirlings can reach 50 percent of this maximum theoretical value.
With a ambient (sink) temperature of, say, 110F (316K) and a temperature of 1400F (1033K - Actually a conservative estimate) our Carnot efficiency is 69.4%. A real high-end Stirling can reach 50% of that, or nearly 35% thermal. After you generate the electricity you are *still* looking at 25% overall efficiency or better.
All that stuff cleans and maintains itself at no cost.
Practically would! If a crew of 3 guys can take a hose truck and rinse the dust off the mirrors of each dish in ~15min, they can do about 30 dishes per day. Each dish would probably only need to be washed once a month, so 30*30 = 900 dishes a month. You'd need 23 crews of 3 men each to maintain 20,000 dishes, or 67 people. A 500MW coal plant would employ about 100. (Guestimated from here) Moreover, the people running a coal plant would have to be skilled to maintain the high pressure steam equipment, which means they would cost more. You would not need special training and licensing to operate a hose truck.
As for the Stirling gen sets themselves, they are hermetically sealed and virtually maintenance free. You can contract out any service that might be required rather than having your own staff. In fact, I would think SES would offer a nice warranty that includes service, so if one does go down simply replace it with a spare unit (They are small and modular, you know) and send them back for service.
The tracking systems are also fairly low maintenance and could be contracted out.
So in light of the above, you may wish to revisit your calculations.
They make a breakthrough and develop an efficient Stiring regenerator, which is simultaneously long and short, conductive and insulating. See : www.tinaja.com/glib/muse116.pdf
So you based your argument on three sentences (one copied almost verbatim) from a journal that seems to deal mostly with electronics? Brilliant. You, sir, seem woefully uninformed about how Stirling engines operate. I will grant you that the regenerator is perhaps the biggest hang up when it comes to design, but by no means is it impossible to create. What you are tying to do is make a medium that stores and rejects heat quickly ("highly conductive") with minimal internal volume ("long and thin") and low pressure loss for gas flow ("short and fat") and does not create a thermal short ("highly insulating"). In practice, a stack of fine mesh stainless steel screens works quite well. I have also read storied about people stuffing the passages in the engine with brass wool to great effect.
=Smidge=
Well the problem is hydrocarbons contain a lot of energy, so what made all that energy decide to concentrate itself like that? There had to have been some driving process that took a very large amount of energy and converted it into a slightly smaller but more concentrated form of oil. Plants fit this bill very nicely, since they take solar energy and convert it into more concentrated, carbon based forms.
Also, processes like Thermal Depolymerization demonstrate that biological material such as plant and animal matter can be turned into hydrocarbon oil with heat and pressure in a relatively short time.
Both are very compelling arguments for bio-based oil.
What other theories are there? (Honest question)
=Smidge=
Why piss away the energy converting it to hydrogen when it's already in the very useful and efficient form of electricity?
=Smidge=
While I suppose you could argue that hydro is an indirect form of solar energy, that's... not quite the same thing, is it? :)
=Smidge=
*facepalms*
:)
Well a spellchecker can only do so much at two in the morning
=Smidge=
Stirlings really do work. The biggest problem is getting them to produce decent amounts of power.
They generally use exotic materials and hermetically sealed, unlubricated crackcases to boost the pressure of the working gas to thousands of PSI (the stirling cycle is completely closed). Usually hydrogen is the gas of choice, but methane and helium are also used.
But you can build a working model out of old tin cans if you were so inclined. Mechanically, the simplest stirling cycle engine has only two moving parts!
=Smidge=
But it's not free.
If you ever have something shipped, including mail order that you pay S&H for, via UPS you're paying for it (and all the other people who did the same) through increased shipping charges. UPS takes the loss and makes it up through their prices.
=Smidge=
Well maintained vehichles and well maintained roads...
Maving experienced a blowout at 85MPH, I can assure you that you have pretty good control over your vehicle.. just don't expect to take any tight turns and leave plenty of room for braking! Control gets difficult once you slow down.
Similarly, at higher speeds you would need a HUGE pothole to have it effect you. Something an inch or two deep and a foot wide will barely be felt.
=Smidge=
Thank you very much. Good stuff.
Based on this, we can take a huge bite out of that 32.8% publication cost. Make it 15%, let's say, since there will still plenty of other expenses to cover. You are not running printing presses or buying ink/paper anymore... storage is also a non-issue, and a great cost since books need to be stored in climate controlled conditions. (So do servers, I suppose, but not on warehouse scales)
The 15.6% "marketing costs" isn't broken out, but it does mention cost of free copies given out to professors. So that can probably be reduced a little bit but I won't guess at how much.
I won't touch anything dealing with the college store since that's not a cost the publisher can do anything about, although there would definitely be savings on that end.
The 10.2% general is also interesting. It's not clear from this what taxes are being paid.
Not that I was expecting even this much detail of a breakdown, of course.
But from this, let's say the publisher cuts costs by 15% instantly just from materials and probably another 10% from all the other places*. Do you think this savings will make its way to the student?
(*I'm sure this would require at least some fundamental change in the way the publisher operates, so that would take some time to realize if it ever is)
=Smidge=
I would like to know how you can assert that "the upfront costs 'U' are fairly high and run in the thousands for amature(sic) books and much higher for more proffesional(sic) books that are generally used in colleges." Do you have actual figures?
I honestly can not produce any real numbers as to how much the author's costs are or how many copied a textbook typically sells, but I find it easy to believe that the cost per book is not a substantial part (>10%) of the sticker price. If you could produce some numbers I'd appreciate the information.
If the publisher expects to sell 20,000 copies, (Number of copies taken from an example here, assuming first year cost recovery only) then if the $80 book still carries say $60 worth of "U" costs (Because R is essentially 0 for electronic formats) then that's a total of $1.2M paid for the production of the book. Any publisher that blows $1.2M putting a book together probably needs to be audited by the feds. Plus, that's only $400k in profit.
So how much does a publisher buy the rights to a book for? You are asserting that it's relatively high, so please provide a source.
=Smidge=
Explain, please, how the introduction of this DRM e-book diminishes or eliminates availability of the following:
First, let us not try to gauge any impact on existing media, but rather the future of media if this becomes the norm.
- libraries, which are generally cost-free to the user, can provide access to books, magazines, technical/medical journals, and the Internet
How do you lend someone a DRM'd eBook without defeating the purpose of DRM? How do you handle licensing issues when before the library could only lend to as many people as it had physical copies? If you restrict the total number of copies, what happens to people who don't "return" the DRM'd copy? etc etc
bookstores selling inexpensive new books (e.g. paperback)
Again, this is current way of doing things. The new way would be via eBooks. Publishers are not likely to reduce the cost of their $100 book all that much regardless of the fact that it costs nothing to reproduce, plus there will be DRM which I'm sure they will add to the price even though it costs them nothing extra.
bookstores selling used books, often at a small fraction of the original price
With eBooks there is no such thing as "used" anymore. eBooks will not wear out like a physical book will. All copies are new copies even if the DRM license is somehow recycled to a new user.
information available on reputable web sites (for access issues see Libraries)
That information is not a replacement for a textbook, unless the book author or publisher has created an online version. Web sites are great supplements, but when the professor tells you to read chapter 5 for the test next week a website isn't going to help.
Not that DRM'd eBooks make any difference in that respect, so I'm not entirely sure why you brought it up.
People that want to learn will find a way. Whether that learning takes place inside or outside the halls of academia depends on the individual.
Ah, that's why. Too bad universities also offer things you can't find easily on the "outside" - like access to laboratories, materials and other facilities and equipment, direct communication with people knowledgeable in the field (professors, lab technicians), and accreditation recognised by potential employers (or clients if you plan to work for yourself).
No one is required to buy the e-books, so your classist argument falls rather flat.
No one is required to buy the eBooks... yet. Or rather, they are still offering the printed versions because they want to see if they can get away with all electronic versions without too many headaches. If they can sell you a printed book for $100 (With like $70 profit) they will gladly sell you a $80 eBook for nearly $80 profit, since cost of duplication and distribution is virtually nil. You'll buy it because you'll save $20.
I wouldn't be all that surprised if they just closed the book stores and sold you the eBooks directly, adding the cost to your tuition. ("Sure the tuition is more expensive, but at least I get free* eBooks!")
=Smidge=
The best part is, not only did you repeat what five other people just said... but you still got it wrong. F5 toggles manual driving, not F4.
You lose! Good day sir!
=Smidge=
It's not really a game. Minimally interactive demo really...
Arrow/WASD keys control steering and accel/brake, but the car drives itself to stay on the road so you really can't steer. 1-4 selects a road/scene, C adds 8 cars, K toggles palette rotation.
With palette rotation this would almost make a good screensaver...
=Smidge=
Actually, yes. It might not be camera parts, but they typically have a (very small) section where you can buy overpriced and shit quality parts for electronics projects, as well as things like cable connectors and oddball batteries.
But 99% of all the places I've been to (That is, 99% of each location - 100% of locations!) have been dedicated to selling satellite TV, stereo equipment and toys, with a sales staff that has no training or experience other than selling you cell phones.
=Smdige=
35mm film cameras outsold Wet Plate Photography kits by a ratio of over 1,000,000:1
The moral: If you don't feel digital cameras are as high a quality as film cameras, you really have to admit they come pretty close and will only get better. Even if they are not-quite-as-good-yet the extra flexibility and convenience more than makes up for it.
Progress marches on. Quit bitchin'.
=Smidge=
Sounds more like Radio Shack to me.
=Smidge=
pff Survivors in Toronto's crash last week 100% survivors in NASA's last crash 0%...
Not to downplay the survival rate of that particular crash, but let's put things into persepctive:
Flight 358 had just touched down and failed to stop before running off the runway and into a ditch at less than 90 MPH.
Columbia was travelling at roughtly 18,000 MPH when the heat basically melted the craft, causing it to disintegrate.
That's a pretty rough comparison. Having said that, how many commercial aircraft have exploded mid-flight and had any survivors? And none of them were going 18,000 MPH!
=Smidge=
"186 miles per hour (300 kph) - more than 270 feet per second."
Or 499,968.9936 furlongs per fortnight, if that helps you put things into perspective...
=Smidge=
The colder your source (Outside temperature) the less efficient they become. If you live somewhere where it gets to be really cold outside, the unit will not be able to pull any heat from the air. In the southern New York climate region where I live, all the heat pumps I've ever seen needed electric heat to make up the difference. (And it doesn't get that cold here!)
:)
Just look at the equation: Thot / (Thot-Tcold)
As Tcold gets closer to 0, (Thot-Tcold) gets bigger and your COP gets smaller.
In practice, you reach an outside temperature where the cycle your heat pump uses fails. For example, a heat pump that uses a phase change refrigerant will not be able to "boil" the refrigerant using the outside air because the compressor can only lower the pressure so much. Once you reach that point you can actually damage the unit by trying to run it.
And I want to kick the guy who wrote that article
So anyway... for the general case, straight electric heat will always be a dependable heat source regardless of temperature... unless it's so cold your heating element becomes superconducting!
=Smidge=
Where else does the waste, lower efficiency go? It has to come from somewhere and go somewhere.
Heat. Only it's heat where it isn't that useful to you... like as latent heat in the humidity you're generating and higher wavelengths (visible/near visible light).
Yes, making heat can be 100% efficient, but it isn't always that way depending on how you want to use the heat. In this case, an electric IR heater would probably do a better job heating the space and a flourecent/LED lamp would do a MUCH better job creating light if those are your goals.
=Smidge=
And what do you do with the sunlight? Convert it into electricity...
Electricity is the "highest quality" power source we can get. Easily stored (batteries, capacitors), transported (wires, EMF), modified (transformers), easily converted into other forms of energy with outstanding efficiency compared to other forms, and in itself completely nonpolluting.
So let's piss away a good portion of the energy we have as electricity by making, storing and distributing Hydrogen!
And Nuclear, while very good and useful, is not renewable and extremely polluting, though thankfully not in the same quantities as traditional power sources like coal...
=Smidge=
Cos if it takes more energy to split the water than the split water produces in heat output...
By definition, at best you'll break even. Unfortunately you will lose some energy to entropy, so there is a net loss. Remember: Every time energy changes form, there is loss. The "hydrogen economy" is bunk because you need to make at least two extaenergy conversions (Form hydrogen and burn hydrogen), but does not address where the energy comes from to begin with.
Anyway, if you want heat and light you are better off using the electricity for electric resistance heaters and lightbulbs instead of generating hydrogen with it. MUCH more efficient.
=Smidge=
That's what I was getting at: If the creator can simply exist, then why *we* can't simply exist?
=Smidge=