No, I get it, I just thought it was funny. You see all the names of these scientists and then you see his name. Regardless of his academic credentials, all you can think of is his radio show.
That graph you posted has nothing whatsoever to do with photovoltaics, it's just a list of the percentage of our energy that comes from "solar" sources over time, with wood being counted as a source (justified I suppose, by the fact that photosynthesis allowed the trees to grow in the first place). All that has to happen on that graph for "solar" energy sources to be continually less of a % of our energy regime is to reduce the consumption of wood products as an energy source, increase energy production from things like Hydro, gas, coal, etc. and the slice of the pie that it occupies becomes smaller. It's no secret that photovoltaic energy output is (and always has been) well under 1% of all energy production in the U.S. but suggesting that making more of them somehow reduces the amount of energy given to the grid is not only counter intuitive it's flat out wrong. The only accurate thing you could say about the manufacture of solar panels is that they create a short run energy debt in order to manufacture and deploy them, but given enough time they recoup that "debt" and become net energy gainers. This is about utilizing (essentially) limitless extra terrestrial energy vs. ultimately limited terrestrial sources. the biggest drawback with solar is that it takes several years to overcome this energy "debt" incurred from the manufacturing process -- you don't just spit out a photovoltaic cell and have it generate all of the energy that went into it's manufacture and immediately enable your hypothetical situation where a cell is created and it magically has enough energy to create two duplicates. Here's a couple of things from the department of energy that explains it far better than I can. http://www.nrel.gov/docs/fy05osti/37322.pdf http://www.energy.gov/news/4503.htm
There's nothing wrong with the graph. Before electricity, the only energy man used was burning wood and whatever came from the sun; burning wood was a tiny fraction of it all, we basically were 100% solar energy powered. If it costs 1000 watts to make a solar panel and it produced 900 watts, it's quite obvious why the more we produce the less a % of energy is from solar. You have to be very careful when looking at the claims and statistics of the solar lobby. They're not including the cost of replacing batteries and recycling them, and they're spinning the numbers based upon a best case scenario that isn't practical. Sun overhead on a clear day at the most optimal spot on the face of the earth, and panel directly facing the sun. The lifetimes of the cells are theoretical, as well - few, if any, are going to make it to their full lifetime; they degrade over time, the lifetimes are again for ideal conditions, they get replaced with "better" ones, etc. When I say 10% to 15% efficiency, I am giving the industry credit for all the advances they could possibly make, but am including all the other factors they're not going to brag about. As an aside, do you know of any company making solar panels that uses 100% solar energy in the production?
You don't understand, so I will try again. Solar panels do NOT PRODUCE energy. The first law does NOT apply here, because they are not producing energy, they are CONVERTING energy. There is nothing else to understand. The control volume can be drawn around the panel. You have EM energy from the sun coming in, and electrical energy leaving. The ratio of these two is the efficiency. No energy is being produced. If you leave it in the Sun for long enough, it WILL convert more energy to electrical energy than it took to create the panel. The efficiency is simply how long it will take to break even. I'm not a fan of solar energy, so I'm not looking to argue in favor of solar. However, it is misleading to start using the First Law as an excuse for why we should not use solar. It just does not apply in the way you are attempting to use it.
I am not misusing the 1st law. You have a closed system that includes the MANUFACTURE of the solar panel as well as MAINTENANCE. You are putting energy into the system by burning coal or gas or oil somewhere to manufacture it and burning gasoline to drive it to where it is installed, and you are getting less energy out than it cost to produce before it stops working. Otherwise, we have found the holy grail - something akin to a perpetual motion machine. It may be confusing because part of the closed system is somewhere else - upstream. They have the same problem with wind power. It costs more energy to make the windmill than it'll produce in its lifetime.
If you want to extend the control volume out that far, you have to extend it around the sun as well, since that is the energy we are converting. I don't know how else to say this: solar panels and windmills do NOT PRODUCE energy. Since you continue to say they do, it is clear that you don't understand how to apply the First Law. You ARE misusing the First Law. Do you honestly think that solar panels are PRODUCING energy? If so, then it would get the same amount of energy out of the panel whether it were sunny or cloudy. It is converting energy, and thus, you can't apply the First Law like you are trying to. The First Law is what keeps us from having solar panels that have an efficiency of greater than 100% (or even approaching 100%).
In no system but a nuclear chain reaction is energy produced, it can only be changed from one form to another. This is true for a gasoline engine or a solar panel. You are making the mistake of imagining that solar panels are magically created with no mechanical processes involved, or energy applied. Or that the energy converted isn't fungible.
Wow. Now you are breaking the First Law. Even in a nuclear reaction, no energy is produced. It is once again, converted to a different form of energy. Nope, I'm not forgetting that at all. That is why I mentioned above that it takes time to convert as much solar energy to electrical, usable energy, as was put in to the manufacturing of the panel. That amount of time is based on the efficiency. The First Law is what limits this efficiency.
It is the conversion of nuclear mass to energy, not one form of energy to another. e = mc**2 The first law does limit the efficiency if you look at the panel on its own. Again, there's a closed system where you are putting energy in.
I don't mean to be rude, but you really don't understand what you are talking about. You can't draw a closed system around a solar panel, unless you are including the sun. Do you understand what a closed system means? This is why are you misusing the First Law.
I am including the sun, but I am not looking at the solar panel by itself as a closed system. But there's a bigger logical closed system that includes the manufacturing and delivery and so on. And ALL of the solar panels deployed everywhere. Your portrayal of this is solar panel + sun, mine is solar panel + sun + all the upstream things that are the fuel for a much larger (but still closed) system. An anecdote: I bought a Prius, thinking that I'd be driving around causing very little emissions. Turns out that to make the car, more emissions were created to make the car than it saves over close to 150K miles. Turns out that a Hummer, all things told, is more carbon footprint friendly.
Good, because solar panel is nothing close to a closed system. That is exactly the point. Your portrayal of this is solar panel + sun, [/quote] No, it isn't. I understand that manufacturing, transportation, implementation and destruction all take energy that must be included. Ok, if you are calling the system that you have defined as closed, there your argument about the First Law is moot. If you know what a closed system is, then you'll know why.
I took the time to draw two diagrams: what you call a closed system, and what I call a closed system. The 2nd is too simplistic (there are certainly more factories), but enough to illustrate the point. I'm not including the ore mines where the metals are dug up, the mills where the ore is converted to metals, and that kind of thing. Equally important but missing is the 2nd solar panel installation in Canada, where there's less sunlight. And the third, etc. Also missing are the recycling plants. Expected lifetime of the solar panels are (EXPECTED) 20 years before you are almost certain to replace them (put more energy in, 15 years is probably pushing it). For Canada, expect maybe 10 years. Expected lifetime of the batteries is 3-4 years (put more energy in).
I'm glad you took the time to draw the diagrams. I see where the confusion is now. You don't know what a closed system is, because neither diagram you drew represents a closed system.
Yes they do. http://en.wikipedia.org/wiki/Closed_system Every part of my closed system is isolated from the environment. A better version of the same image:
No, you really don't understand. Both of your diagrams show energy coming in, sunlight, and energy leaving, eletrical energy. By definition, that is NOT a closed system. A closed system would NOT have energy inputs and outputs. Like I said, neither of your diagrams represent a closed system.
With all due respect Denny, you're trying to have it both ways (and I'm not sure what throwing the emissions argument into this has to do with the price of tea in china). Furthermore, your claims that nuclear energy is "created" from the chain reaction, decay of atomic nuclei is wrong -- that energy is contained within the the atom and is released in a fission reaction; the fact that it creates a cascade effect from a small energy input is irrelevant. And finally your assertion that wind turbines and photovoltaics never end up generating (converting) enough power to overcome the energy it took to manufacture and deploy them is simply and utterly incorrect. Each type of energy collecting device has finite, fixed costs associated with their creation (in energy terms) once deployed they then begin converting wind or radiant energy into a certain amount of kilowatts of power ad infinitum, or until they break down mechanically. Let's put it another way, 200 years ago a miller decides that instead of using a hand-crank to mill grain he's going to build a new mill next to a rushing creek, and will use a water wheel to power his mill. the costs in energy terms to build the mill can be counted in the calories expended by he and his ox: cutting and hauling lumber, the carpentry involved with building the mill, etc. Let's say that it took the equivalent of ten bushels of corn (in calories) to supply the calories needed to build this mill; that is a fixed, finite cost. Now the mill is up and running and the water wheel is cranking over and over and over, generating a certain amount of kilowatts (or kilocalories) of energy each minute, hour and day that it is allowed to run. Eventually that mill is going to have "captured" or converted enough kinetic energy, from the creek, into more calories or kilowatts of energy than were consumed in the manufacture of the mill and its wheel. In any case I'm done arguing, if you don't get it, there's probably nothing I or anyone else can say to convince you otherwise.
I think you don't understand. The next sentence from wikipedia: In physics, a closed system can exchange heat and work, but not matter, with its surroundings. And to quote you: You can't draw a closed system around a solar panel, unless you are including the sun.
The cost isn't finite, this is not a correct assumption. The lumber breaks, the mill stone wears out, you do have to continuously feed the oxe, you have to clean the algae and junk from the paddle wheel in the water, and where parts touch they're going to wear out. This is why the trend in windmill technology is to make them hugely larger - the hope is that they do capture enough energy before they wear out.
