WHAT IS ENTROPY?

As long as the general public has no idea about the behavior of energy, politicians will go on wasting the taxpayer's money on dead-born "green" projects!

You may have heard that entropy is a measure for disorder, or chaos, but this is not true and in any case a useless definition for the layman's understanding of what renewable energy is all about. As explained in the video here, entropy is about the dispersion of energy, finally to spread out in the environment at ambient temperature. At that point it has reached its highest (relative) entropy state, which means that we can't make any use of it any longer.

To understand this all better, we must examine what the first and second laws of thermodynamics imply. The first one you probably know as saying that energy cannot be created, nor be destroyed. Although true, that is not the law itself, but a consequence of it.

It doesn't give any understanding, for which reason many think that Hydrogen from the electrolysis of water is an energy source. The correct formulation of the First Law is that the energy applied to change the condition of a system, is exactly the same amount that must be removed to bring the system back in the original condition. If there were any difference, energy could appear out of nothing, or disappear into nothing, which thus is the consequence of the First Law.

With this you can understand that if the system is water and you split that water in Hydrogen and Oxygen by using electrical energy, then the exact same amount of energy appears as heat when combusting the Hydrogen with Oxygen back to water again (at 100% efficiency) . Only a part of that heat energy is converted to mechanical energy in the engine, while the greater part exhausts as hot steam, condensing to water in the surroundings. You have thus gained nothing, even lost, by having used far more electrical energy than what the engine gives off in mechanical energy - an electrical motor would have given you much more!

In other words, would it be possible to use water as an energy source, we would be creating energy out of nothing. However, you may buy Hydrogen, just the same as you would buy gasoline, and then of course Hydrogen would be a fuel FOR YOU, but NOT an energy source for the society, still burning fossil fuels or whatever, to produce that Hydrogen and far more than what the user (you) gets out of it (electrolysis gets hot, only 60% efficiency, combustion engine 20%, total efficiency is 12%). Hence, energy from Hydrogen is not renewable energy!

Naturally, if the energy source would be from solar and wind, it would become renewable energy, but the exorbitant size of the installations for this on a nationwide scale, would not be economically feasible, neither would it be practical in any case. Geothermal energy would have a far greater potential for this.

Where did all the energy "used" to produce Hydrogen go? Yes, it all (including the mechanical work developed) became heat, finally cooling down to ambient temperature, dispersed in the surroundings. You may see now that we do not "produce", even less "consume" energy, but fuels instead - we can only convert energy from one form (in the fuel) into other forms, finally everything becoming heat at ambient temperature. It's here where the Second Law and Entropy comes in. The Second Law simply implies that all flowing(!) energy spreads out into larger volumes and entropy is the measure of it.

Ironically, Clausius coined the notion of entropy, but didn't use it to formulate the Second Law. Had he done that, there would never have been any confusion on the subject and nobody would think today that entropy is a measure for disorder. That it became this way, is because particles and energy are not separated in the line of thinking.

When particles/things are spread out in a disorderly manner (shuffled cards for example), there position for a given moment in time has become unpredictable to a lesser or larger extend and thus the resulting disorder (chaos) is greater, the more unpredictable these positions are. Unpredictability is thus the measure for chaos. When energy is spreading out, regardless in what form initially, if not constrained somewhere along the line, it finally becomes heat at ambient temperature. Change of entropy is the measure for how much energy has dispersed to what extend and has thus nothing to do with the unpredictability of chaos.

You can find entropy extensively explained here: http://entropysite.oxy.edu/