ENERGY, ENVIRONMENT AND POLLUTION
Energy is a term that everybody knows and discusses in connection with environment and pollution, or at all, but yet science doesn't know what it is. What we do know however, is how energy behaves and the prime physical law that describes this behavior is the First Law of Thermodynamics. For the layman it means that energy cannot be destroyed, nor created from nothing, but nevertheless energy production and consumption, are a widely used terms.
Fact is that we only can convert energy from one form into another one, but whatever we do, all energy that we convert ("consume") decays to heat at ambient temperature, that of the environment - it's still there, nothing was "consumed". It's no different with our planet as a whole. All energy it receives from the Sun (the absorbed part of it), is radiated back into space at the same time and this is necessary to keep the average temperature of Earth, our environment, at a constant value. If there would be any persistent difference, we would either freeze, or get boiled. Hence, the Earth does not "consume" any solar energy and if your bank account would behave the same way, you would never be able to take one single penny out from it - whatever comes in, goes out in the same moment. Nevertheless, the money flow keeps your bank account "alive" and so does the flow of solar energy, keeping our planet alive, just by flowing through it.
In the public concept however, solar energy is more considered like filling a bucket with water. If it would have no bottom, you could not fill the bucket and thus the 'bucket-earth' appears to have a bottom, that allows us to "consume" the energy with which it is filled. But then, energy can be stored also and that is f.ex what happens in our body, or in that of any living creature. It takes in energy in the form of food, and gives it off again in the form of body heat. The body radiates off energy (heat) all the time, but we do not eat all the time. The energy that the food gives, is initially stored in the body, that radiates it off at a lower rate, but over time there is energy balance - what comes in, must go out. Thus the Earth could be seen as a filled bucket and all water (solar energy) that is poured in more, flows out over the edge.
Much (solar) energy is stored in the systems of the Earth and during the time this energy was stored, the Earth radiated off less energy, than it absorbed from the solar radiation and so the global temperature rose. While rising in temperature, the Earth radiated off more and more energy, until a balance was reached at a certain temperature, that from then on remained constant - the "bucket" was filled. Whenever the radiation capacity of the Earth changes, like due to a change of the atmosphere's composition, the environment, the Earth's temperature will change also, until a new balance (equilibrium) is reached.
This is what we today experience with "Global warming", due to pollution - the Earth is seeking a new balance temperature. Global cooling can occur also, if the atmosphere would change to reflect more solar energy and thus absorbs less - its temperature will go down to reach balance again. But because the storage capacity of the Earth's systems is huge, especially that of the water in the oceans, covering 70% of the Earth's surface, such changes will go very, very slowly, hardly noticeable within a human's life-time. It are the oceans that stabilize the temperature of Earth - enormous amounts of energy must be taken up, or given off, a vast multiple of what the world converts today with technology, to change the temperature of the oceans measurably.
Important to realize is thus that the Earth is not receiving a net surplus of energy. Whatever comes in from the Sun on one side (day), is radiated off on the other side (night).
It is not only heat energy that is stored in Earth though. During many hundreds of millions of years, solar energy was stored in chemical bonds of various kinds, not in the least biological ones, some of them being what we now burn as fossil fuels - "ancient" solar energy (actually it's latent energy, but you can ignore that). When we burn these fossil fuels, basically the same thing happens as with the incoming solar energy to Earth. The (latent) energy in the fuel is released at high temperatures and in our machines and devices converted into various different forms, but all finally winding up as heat of ambient temperature - nothing was "consumed". Only the fuel was consumed, but not the energy converted from it - it simply is added to the environment. Nevertheless, it made your car move and the fuel you paid for is gone and this is the confusing thing for the layman, as if the car had "consumed" energy.
All we do with our energy technology is to bring energy from a higher density level, or "high quality" to the lower energy density of the environment. In other words, we "spread" it out in the environment. This is what we do with our fuels and the same what the natural systems on Earth do with solar energy. This all has to do with entropy - click here to read more on the subject.
From this we may understand that the larger the difference in energy quality is (its density difference), the more we can make use of, ic the higher efficiencies we can achieve. Thus if an energy source already is widely spread in nature, we can't spread it out much more and thus there isn't much we can do with it. This simple fact is largely ignored when talking about bio fuels, like ethanol, methanol, palm oil, etc. The sources are large fields, where the stuff grows, widely spread over vast areas and so we have to harvest these crops and collect them. Not enough with that, we also must prepare, convert them into a form that can be used by our machines and devices. In other words, we first must increase the quality of these energy sources, before we can decrease it by usage and this takes a lot of initial work to do - the net result, the total efficiency, at least in economical terms, becomes very low.
The same applies on solar and wind energy - they are widely spread in nature and we have to collect it to bring it in one point, where we can use it. With this in mind we can consider the aspects of pollution. When it is said that f.ex bio fuels are more environmental friendly than fossil fuels, one only considers the fuels as such, but ignore the processes and systems needed to provide them. These processes and systems are in themselves pollutant, like using machines and trucks to harvest and to transport and whatever else to prepare the fuels for usage. Apart from pollution, these collecting and preparing systems take up the major part of the energy we finally get out of it on the user side - not much left.
The same with solar and wind energy - the large supporting, energy-intensitive and pollutive industry behind these systems (which actually is a high-tech one) is ignored and then of course, these renewable sources appear to be very environmental friendly. They also appear to be "free", but no, we have to pay to get them readily supplied and maintained for usage. In any case, as these sources were widely spread in nature and we want to spread it even more by usage, which isn't very much more, the economy of such systems fail. Moreover, if we would want to replace high quality energy sources like fossil fuels and nuclear power with these renewable sources, the areas needed become so huge, that our planet likely isn't big enough to satisfy a global demand (which is increasing as well). Mind that only 10% of the world's population converts (uses) 80% of all energy. Imagine what would happen if all third world countries today, would become high users as well!
At this point it is interesting to consider hydro-electric power, also being a renewable energy source, directly (with some delay) from solar power. The natural systems of the atmosphere, powered by the Sun, evaporate water from the oceans, transport it up to high altitudes, by which the potential energy increases, condense it by rain and collect it into high positioned reservoirs (rivers, lakes, etc) and so we don't have to do a thing to get it ready for usage - it indeed is a free, high quality energy source, easier to get by than fossil fuels. Of course, if we build artificial reservoirs and dams, rerouting rivers, etc., it isn't that free any more, due to the large investments needed and the environmental aspect becomes worse also, due to the polluting industry behind these constructions and the impact these constructions and installations have on wild-life around, but nevertheless.. Over time, once the investments are earned back, we do have practically free hydro-electric energy. In fact, this is the only renewable energy source that is technically and economically feasible!
Not quite, another one would be heat-pumps, that in one location collect ambient heat from large remote regions of the environment, brought to it by the natural flows of water and/or wind and output around three times more energy than is needed to drive them. Unfortunately they are polluting by using fluorocarbons and the like of refrigerants, that cause ozone depletion. Moreover, also a wide usage of heat-pumps would require a pollutant chemical and a manufacturing and maintenance industry to support it and the initial investment level is high, usually too high for the private household-users. However, a new technology , that the powerful committers of the oil and gas industry never want to see developed, may give a solution.
But then, what is free (gratis) energy? Fossil fuels are also provided for free by nature, but just look at the high oil prices today - for free, only the Sun gets up! Right, solar power, being available everywhere on the planet, would be free, just there would be a víable conversion technology, apart from hydro-electric power, unfortunately not being available everywhere, yet to develop from scratch... !
Next to consider is the rather hot potato of Hydrogen as an energy source. First of all, Hydrogen is NOT an energy source, simply because it doesn't occur in free form on Earth, even though it in its chemical bond with Oxygen (water) is the most abundant element on Earth. To free it from this bond however, takes a lot of energy and so the same as discussed above applies. Many hydrogen applications that are under development, basically burn Hydrogen with ambient air and so the combustion product is very environmental friendly water...in the form of steam. At this point we should closer look at the First Law of Thermodynamics, which more correctly says that, if you bring a system from one condition into another by adding energy to it, the same amount of energy must be removed to bring it back in the original condition, no matter in what way it is done. Naturally, because if we could take out more energy than was added previously, the surplus energy difference would come from nothing. Inversely, if less energy would be taken out, the deficit difference would disappear into nothing. Now, let us apply this law on any hydrogen engine:
Let it be a black box and we poor water at ambient temperature in on one side (condition 1) and get steam out on the other side (condition2), plus mechanical output power on the shaft ...do you see it? The output would be larger than the input and so the input must be increased with additional energy to make balance. We do that in whatever way and what becomes the result? The output steam (condition 2) will finally, regardless in what way, become water again at ambient temperature (condition1). Then the First Law thus implies, that whatever more energy came out of the black box, like mechanical power on the shaft, is exactly the same amount that was additionally applied to the input - there is no gain!
If we instead prepared Hydrogen and put that into the black box together with air, then the energy needed to having prepared that Hydrogen will be exactly the same as what the black box outputs in usable work and surplus heat and again, no gain ( in the ideal case at 100% efficiency - in practice we would have a loss). More or less the same happens in so called fuel cells. They are fed with Hydrogen and Oxygen and produce electricity and steam as output. This apparent 'gain' of output energy is exactly the same as what was needed to provide the input Hydrogen and Oxygen (using fossil fuels or whatever) and thus Hydrogen is an energy converter only and not an energy source!
However, there are other chemical processes, like using natural gas, such as methane (CH4). If we use that as an Hydrogen source, then the condition of the output (water in the end) will NOT be the same as the input condition (methane) and thus the First Law allows a net surplus output. So there is, but the efficiency is just a few percent higher than burning the methane directly with air in a combustion engine. It would be more environmental friendly though than using fossil fuels and in a fuel cell, more environmental friendly than direct burning, but a more complicated and expensive technology - economics give the feasibility.
CONCLUSION:
All tough there are several interesting alternative energy designs, the problem in the end is availability of quantity and distribution, apart from economics. If we are considering the global condition, many in itself interesting alternative energy systems only are more or less feasible in local applications, but not on a global scale. Just imagine that the world today burns around 30 million barrels of crude oil A DAY, plus twice the equivalent amount of coal (coal is still the world's main energy source). If we then consider that actually the main fuel is atmospheric Oxygen, one can wonder how we still can breath!
One thing is clear though , the longer we use fossil fuels as main energy source, the surer our Earth will become unlivable - catastrophy is ahead! We MUST do something and we are running out of time. Therefore, the only short term alternative I can see is a vast increase of nuclear and hydro-electric power on one side and more energy-efficient user applications on the other side. On a longer term scale, new energy technology is needed, but first things first.
However, the main pollutive factor for our planet is our numbers, regardless what technology is used, the latter "only" determining the time scale of events. Expansion into space appears the only way to relieve the ecological systems on Earth, or to reduce our numbers drastically, which will be Mother Nature's preferred method - we rather not wait for her to strike without mercy!
AFTER ALL, WE NEED THE WORLD, BUT THE WORLD DOESN'T NEED US - WE ARE MORE THAN DISPENSABLE !