Posted on 01/23/2005 6:45:16 AM PST by Blood of Tyrants
LOS ANGELES — Hydrogen-fueled cars have been hailed as the future of transportation — clean, safe and propelled by a power source whose only by-products are air and water.
[snip]
The problem, critics say, is that the technology that makes the fuel of the future generates just as much pollution as the gasoline-powered vehicles we drive right now.
[snip]
Extracting useful quantities of hydrogen from water requires a massive amount of energy — energy that typically comes from burning oil or coal.
(Excerpt) Read more at foxnews.com ...
Sorry, I stand by my statement. The earth is ground, but it is not a good conductor. The power companies keep one of their lines used for the return path close to ground (except for three phase delta circuit which uses no ground, including no earth ground. They do this by grounding a line at power poles and at user homes. But this ground is NOT used for the carrying of normal metered power.
Electricians use the term ground for the line that is kept at ground potential, and in a three prong circuit, the "ground" prong is connected to a water pipe, Etc but this "ground" circuit is for safety not carring power. Would you normally suspect that a pair of rods hammered into the ground and separated several feet would be as good a conductor of current as a copper wire? Dirt, even wet does not conduct as well as copper. Sea water even with its salt ions does not conduct as well as copper wire.
Best idea is to do a test. Take a motor and run one wire of the motor to the hot line of a plug, put the other into a good ground. (copper rod hammered four feet into soil). Now try the switch. Since the power is "grounded" to a ground in the house, the saw should run right? It won't even humm.
I didn't say any of it was impossible - just likely to be impractical or uneconomical without new developments of one kind or another. I AM certain of a few things I stated - it will never be a practical replacement for natural gas, for instance. Electricity is a better choice for that. Which immediately reduces the exposure to gas leaks, because it eliminates the residential distribution system where most leakage occurs.
Filling a vehicle tank with a measured amount of H2 gas is a tricky - and energy intensive - business. You mentioned the way gases are sold today, and I think that might be the only practical method for H2. Specifically, vehicle tank exchange. It eliminates the problems of measurement and compression at the filling station.
Your point-to-point pipeline examples are not really a distribution system, because they do not address the number of destinations and the volume required for the application.
But a full unpressurized 20-gallon tank of ordinary gasoline contains about 120 pounds of gasoline, containing 19 pounds (8700 grams) of hydrogen. Not pressurized, the same tank would hold about 6.5 grams (1/4 ounce) of H2. How much pressure to match the same hydrogen density? Oxygen tanks are filled to 2200-2400 PSIG, or 150 to 160 atmospheres. Let's approximately double that - risky with exchangeable tanks - to 300 atm. 300 x 6.5 = 1950 g. or about 4 1/2 pounds. Oops. And how much does the tank weigh to hold that pressure? Maybe we need a better way to store H2.
Actually, I think that really clean gasoline - synthesized isooctane - might just be the fuel of the future. Diesel is too complex to synthesize economically. But octane, that can fuel both combustion engines and solid-oxide fuel cells (that oxidize the carbon to break the hydrogen free, then use the hydrogen to make electricity) is probably the transportation fuel of the future - and when we run out, we will just make more.
But please considerwhat I said before, about running most of our transportation from the electric grid. Today, 2/3 of our oil consumption is for transportation fuel, and over 95% of our transportation fuel comes from oil. Some is aviation fuel, but if we derived 90% of our ground transportation from the grid instead of oil, we would cut our consumption in HALF, and require only a single-digit percentage increase in electric capacity.
And by the way, I never mentioned the Hindenberg.
| 8 | “Or, you can use solar cells to generate the weak electrical field to break the H2O bond ” |
| ref. | source | loss (%) |
power (per m2) |
|---|---|---|---|
| Solar flux |
|
1,368 W | |
| Atmospheric losses |
|
752 W | |
|
|
Night times losses |
|
376 W |
| Solar angle losses |
|
188 W | |
| Cell conversion losses |
|
22.6 W | |
| DC®AC inverter losses |
|
20.3 W | |
|
|
Net efficiency |
|
1.5% |
|
|
Net energy (per m2 per day) |
|
0.5 kWh |
| Value of energy (per m2 per day) |
|
4.3 ¢ | |
| Solar panel cost (per m2) |
|
$530 | |
|
|
Payback period |
|
33 years |
How much energy is that "0.5kWh" daily energy production number in line eight?
--Boot Hill
| 8 | “To generate that potential again by cracking water, you have to put just as much energy in. TANSTAAFL.” |
Agreed! Here's a graphic that makes it abundantly clear...
| process | natural gas (kWh) |
hydrogen (kWh) |
| Energy used to create the fuel | 0.00 | 1.25 |
| Energy value of fuel recovered for generation | 1.00 | 1.00 |
| Electrical energy generated (50% efficiency) | 0.50 | 0.50 |
| Electrical energy diverted to create more fuel | 0.00 | 1.25 |
| Net electrical energy for consumer use (deficit) | 0.50 | (–0.75) |
From the deficit shown in line five of the above table we can see that...
The probability of developing a sufficiently light-weight/high-energy density BATTERY is far less likely than figuring out how to store and transport hydrogen.
"And by the way, I never mentioned the Hindenberg."
No, but on virtually every "hydrogen energy" thread, some ignorant jackass always does.
This one's broke.
How do I get the hydrogen from the off-shore platform back to shore? Where do I store the hydrogen? How do I maintain the platforms and windmills? Lot's of infrastructure will be required.
There is no such thing as "free". Everything has a cost.
I appreciate the statistics - including the formatted table, which I plan to shamelessly steal from you to add to my own collection of useless energy facts - but I question the HORIZONTAL orientation. Why would it not be angled at the latitude value? You have a number for solar angle loss, that probably includes the average of 13.4% loss from this avoidable pointing error.
My solar water heating panels are appropriately angled - it is a trivial task, and allows rain to wash the dust off, as well.
"There are other problems with hydrogen gas such as leakage, reactivity, and transportation."
And gasoline is better how?
Tesla was incredible.
I was surprised when I visitted Niagara Falls to see a statue of him.
Any one who reads his history will be amazed.
The distribution system is already in place, the refineries have already been built, the amount of power available per volume is greater. Need more?
I specifically posted NOT to give me any flap about the third prong...ha
No, I'm not talking about that ground. I'm talking about the black wire and the white wire. I'm not an electrician, and I don't really know a thing about power poles or what the wiring looks like on the other side of the circuit breaker. But If I remember correctly, the black wire is called the "hot" wire, and the white is called the "ground". You can't get shocked by the white wire, but the black wire you can. As I understand it, the reason is that the black wire comes from the power plant, and the white wire is the return, which is connected to the GROUND, that's why it's called the GROUND. And when you get shocked, it's because you are GROUNDED and touching the black wire at the same time...inotherwords, the JUICE from the power plant is cooming to your house via the black wire, then into your body, then to the GROUND, then eventually back to the power plant somehow.
Now, the third prong is something entirely different and is not even required to run electrical equipment. Any appliance or elecrical device has a motor(or load of some kind, like a heating element) and a chassis. Generally, the chassis is just a simple frame made of steel and it has no purpose(electrically speaking, except in cars, in which case the frame/chassis is part of the circuit). It is just there for something to bolt all the electrical junk onto. THe third prong is a wire that goes to the chassis and then to the ground. It's only a safety precaution to protect you from the off-chance that the black wire should somehow come into contact with the chassis and thereby making the entire surface of the appliance or device electrified. If that should happen without a third prong present, you could get quite a jolt every time you touch the appliance if your body is sufficiently GROUNDED TO THE GROUND AS IN YOUR BODY BEING THE WHITE WIRE WHICH IS THE GROUND. At least that's my understanding...I could be wrong.
Now, I could be wrong. If I am I would appreciate you explaning to me where I am going wrong WITHOUT going into all that mumbo jumbo about power lines and power poles. I really don't care to hear about high tension line wiring schematics. Give it to me in terms of household wiring please. If you even breath a whisper about anything the other side of the transformer, I swear Im gonna follow you around this whole site for the rest of the week and flame every post you make...just kidding.
The film can convert up to 30 per cent of the sun's power into usable, electrical energy. Today's best plastic solar cells capture only about six per cent.
Sargent and other researchers combined specially-designed minute particles called quantum dots, three to four nanometres across, with a polymer to make a plastic that can detect energy in the infrared.
Infrared light is not visible to the naked eye but it is what most remote controls emit, in small amounts, to control devices such as TVs and DVD players.Link
And even more in depth data may be found here
You are more than welcome to "shamelessly steal" that table! But first, let me repost it (in the post immediately following this one) with the table notes appended to the bottom, that I had left off for the sake of simplicity. They contain some good additional information and links that you may want.
• "but I question the HORIZONTAL orientation. Why would it not be angled at the latitude value?"
I have a couple of explanations for you, plus a real-world example.
First, the sun light arriving at the PV array is a combination of both direct and indirect radiation. Indirect sun light (or blue-sky radiation) is that light that was diffused and scattered by various atmospheric effects. While the intensity of blue-sky light is very small, nevertheless, the blue-sky contains over 100,000 times the angular area of the sun, so even that small intensity adds up to be a substantial level of flux. The actual amounts of direct and indirect solar flux reaching the earth's surface varies depending on which expert you care to cite, but it is generally accepted to be somewhere in the neighborhood of 25% direct radiation from the sun while another 25% would be indirect radiation.
This means that as you tilt your array towards the sun to increase the direct solar irradiance, you are, at the same time, decreasing (to some degree) the irradiance from the indirect solar radiation.
Second, since the vast majority of solar installations are rooftop installations, you not only have to take into account the tilt provided by the roof, but also its east/west orientation. Since the sunny side of the "average roof" will face about 45º either side of due south, this can negate much of the benefit of tilting the array.
As interesting as the numbers in my table may be, and as informative as the above explanations may also be, what can you expect from a system in the real world?
Shell Solar offered a peak at real-world performance in their document: "Solar Electric System Case Study". This document reports on the performance of a roof top residential installation in sunny Southern California. The array consists of 32 Shell Solar SP75 solar panels.
The report states that the total projected system electrical energy output per year is 3650 kWh. Using the data from the Shell report and the spec sheet for the SP75, the average power production is 20.6 W/m^2. A comparison between that value, and the nearly identical value of 20.3 W/m^2 quoted in line 6 of the table in post #104, suggests that the table data is a highly accurate real-world representation of what one can expect from solar power.
--Boot Hill
| ref. | source | loss (%) |
power (per m2) |
|---|---|---|---|
| Solar flux |
|
1,368 W | |
| Atmospheric losses |
|
752 W | |
|
|
Night times losses |
|
376 W |
| Solar angle losses |
|
188 W | |
| Cell conversion losses |
|
22.6 W | |
| DC®AC inverter losses |
|
20.3 W | |
|
|
Net efficiency |
|
1.5% |
|
|
Net energy (per m2 per day) |
|
0.5 kWh |
| Value of energy (per m2 per day) |
|
4.3 ¢ | |
| Solar panel cost (per m2) |
|
$530 | |
|
|
Payback period |
|
33 years |
|
--Boot Hill
LOL, like I say to all the prophets of a bright new tomorrow, who haven't paid attention to the last 50 years of broken promises and failed dreams...
Ping me when they actually begin shipping product!
In the mean time the table in post #104 represents the most advanced current state of the art actually in production. And the best you can get is the energy equivelent of 2 measly ounces of gasoline per day, per square meter of very, very expensive PV cell.
Deal with the reality, not your dreams!
--Boot Hill
Prepare to eat a big steaming plate of crow. People had the same opinion of the Wright brothers, manned space flight, and setting foot on the moon. No one would ever have a conceiveable need of a home computer. The list goes on.
The chief problem with current solar power is that is just isn't economically feasible, simply stated that it takes far more money to break even than it's worth. But again, that was with a whopping 6% efficiency. Now, we have improved efficiency by 500%, and we also have the benefit of not only using JUST the visible part of the light spectrum, but now down into the infra-red band. Now the economics of the whole situation has changed. With the economics showing a break-even in far fewer years, further research will make further breakthroughs. Just like processor speeds; a little momentum goes a long way.
I'd bet that this will ship within 3 years.
LOL, not a chance! You see, I've NEVER said that such technological advance is not possible. But with some 40 years of technical knowledge, training and experience under my belt, I've also developed a good enough BS detector to separate the pie-in-the-sky dreams from those that actaully have a chance.
• "The chief problem with current solar power is...a whopping 6% efficiency. Now, we have improved efficiency by 500%"
Now that is a fine example of why you need the BS detector I mentioned above. Your "6%" figure comes from the wild-assed claims by the inventors of the polymer film PV cells that have made such a splash here on FR in recent days. And the claims are bogus. The current state of the art for production photocells today is 15%, not 6%! Secondly, they are only claiming that the 30% efficiency is what they "expect to convert" (source), not what they've actually measuring today. And thirdly, laboratory results and real-world results are always vastly different.
• "I'd bet that this will ship within 3 years."
Ping me when they actually begin shipping product!
--Boot Hill
I was referring only to electrical lines and pipelines because they would be impractical as infrastructure for the application.. A platform would require storage tanks with a scheduled visit from a tanker to transfer hydrogen from the storage. Of Course.
Developing the infrastructure to convert to a hydrogen based energy economy would create thousands of jobs. Potentially hundreds of thousands of wind generators and accompanying platforms would have to be manufactured. This would require considerable investment. And yes, nothing is for free.
Some benefits of the wind generator concept is that individuals could invest in their own water containment, hydrogen platform, or form co-operatives to reduce the cost of production, storage and transport and eliminate the middleman from the distribution scheme. Just the thought of people eliminating middleman markups and cutting huge corporate control of energy distribution and price manipulation, is in its self enough to create resistance and misinformation to a shift to a hydrogen based energy economy. No wonder the oil companies are the leading critics of the concept!
Here is where you need to look behind the power box. The white wire is called the Return, and it is connected back to the power plant and ALSO connected to ground. But as per my prior post, all the energy to do good things goes back to the power plant on the white wire. Ground is not a carrier because it is hundreds of times more resistive than the white wire. (copper). You don't get a shock from the white wire because it is held at ground, but a current meter clamped around the white wire will show that the same current flows there as in the black wire. The same meter clamped around the part of the circuit connected to the water pipe will not read current because whatever current flows into ground is too small to detect with the same current meter. There is a small current there, enough to corrode your connection to the water pipe if moisture is present.
And when you get shocked, it's because you are GROUNDED and touching the black wire at the same time...inotherwords, the JUICE from the power plant is cooming to your house via the black wire, then into your body, then to the GROUND, then eventually back to the power plant somehow.
This is interesting, you are correct that you will be shocked by holding the black wire in one hand and the water pipe (grounded) in the other hand. Guess what, you will also be shocked by holding the black wire and the white wire. Now, since the white wire path back to the power plant is low resistance, them more current can flow through your body touching the black and white wire. In fact, it is far more dangerous to touch these two wires than it is to touch the black wire and the earth.
If that should happen without a third prong present, you could get quite a jolt every time you touch the appliance if your body is sufficiently GROUNDED TO THE GROUND AS IN YOUR BODY BEING THE WHITE WIRE WHICH IS THE GROUND. At least that's my understanding
You are correct about why the third prong is there. It is as you say, a precaution should the appliance ever be connected accidently to the black wire.
I am not saying ground does not conduct, it just conducts poorly. Wires carry all the useful current so it will take a two wire circuit to supply Hydrogen generators down the highway. Not really much of a problem except that the cost is two wires not one. Otherwise, you DO understand your house wiring as far as I can tell.
refineries are worthless if there is no oil.
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