WHAT IS ENTROPY?

You may have heard that entropy is a measure for disorder, or chaos, but this is not quite true and in any case a useless definition for the layman's understanding of what renewable energy is all about.

Instead think in terms of 'energy quality', which can be seen as energy density. The more energy is contained in a given volume, the higher the density of it is, the higher its quality. Fossil fuels were formed by the forces of nature during millions of years, by which those forces did the work to convert solar energy into chemical energy and concentrate it into small volumes. This gives these fuels a high energy density, thus high quality energy, which makes them low entropy sources.

The opposite thus is low quality energy, or low energy density and those are called high entropy sources. The lowest possible quality, thus the highest possible entropy, is heat at ambient temperature. For example  1 kg of air (a volume of 1000 liter ) contains roughly 1 kJ of heat energy per degree Celsius, while 1 kg of diesel/gasoline (a volume of 1.2 liter) contains around 40 MJ in  chemical energy. Hence, if 1 kg of air would have the same amount stored as thermal energy, it would have to be heated to 40,000 degree Celsius (the surface of the Sun is "only" 6,000 degrees hot).

All energy technology is about converting low entropy energy to the highest entropy level of the surroundings, because all energy finally decays to heat at ambient temperature. Consider a sailing boat, that does just that. The kinetic energy in the wind causes friction in  the sails and while driving the ship, between its hull and water. This friction causes the kinetic energy in the wind to convert to heat at ambient temperature. Oh yes, purely theoretically a sailing boat "heats" up the atmosphere and the water in which it moves, just that it is too little that it ever could be measured. The same applies on your car. The chemical energy in the fuel converts to heat, initially very hot, by which a part (around 20%) is used to drive the car, while in the end the full 100% becomes heat at ambient temperature. You car and all machinery thus consume fuels, not energy!

Energy cannot be consumed, nor produced (fuels are), but only converted from one form into another and by our technology, the end state always becomes heat at ambient temperature, the highest possible entropy level on Earth. As this energy then is widely spread in the environment, as such unrecoverable, the idea of chaos arises as the meaning of entropy, but that is wrong. Chaos, in everyday meaning, is about the distribution of particles, or the structure of a system, while entropy is about the distribution of energy. Hence, shuffled cards have no entropy.

You now may understand why it is said that there is order in chaos. Matter in the universe appears as highly organized in stars, planetary systems and galaxies, all showing a high order, by many seen as a prove of Divine Creation, preventing chaos otherwise. Fact however is that the stars pour out enormous amounts of energy into space, all of which disperses in it, decreasing the whole of the universe's energy density, increasing its entropy. If entropy would be a measure for order, the universe would be in a state of chaos, no order at all. Instead, the universe is in a state of increasing entropy (caused by gravity to form and maintain its structure = order).

If we apply the above on renewable energy, we can understand that its sources, solar and wind energy, are high entropy sources and thus we can't increase its entropy much more. The source entropy is high because the energy is spread out out over huge areas and therefore we must make a large effort to concentrate it in the point of usage and to convert it into a usable form as well, by which we have decreased the entropy of it. This decrease of entropy we did not get for free, so to say that renewable energy is for free, is a very misleading statement. The source is indeed for free, but the usage of it is not. The same it is with bio-fuels, the sources of them also being spread out over huge areas, needing harvesting, transportation, preparation and distribution systems. In all, the efforts needed to prepare these renewable energy sources for use, make the overall efficiency very low and therefore there is no economy in this for nationwide applications. Only in some small scale applications, there can be a viability.

So it was before the industrial revolution, when sailing ships, windmills and wood as fuel covered all energy needs. With the steam and later combustion engines coming up, by which industrial mass production emerged, only fossil fuels could satisfy the vastly increasing energy demands. Compared with today's situation, only a large application of hydro-electric and most of all nuclear power (by far the lowest entropy source available) would make a difference, but "we" don't want that.  Instead "we" want to return to the renewable energy society of our ancestors, yet expecting lots of electricity in the outlets ....

Also the statement that renewable energy is environmental friendly, is a very misleading one. If we consider the huge polluting industry that is behind to manufacture and maintain solar panels, wind-propellers AND the infra-structure needed to make them usable on a large, nationwide scale, the 'green' aspect of most renewable energy sources becomes very disputable.. These circumstances are fully ignored in everything you read and hear in the media on the subject of renewable energy sources - you're not supposed to be aware of it, rather not.

Apart from that, there are two low-entropy exceptions for renewable energy, not being used by our ancestors, them not having the technology for it.

1. Hydro-electric power. The forces of nature (solar energy) collect rain water in high situated reservoirs, ready for us to use (high quality, low entropy source). However, it is only available in mountainous areas and thus of no significance on a global scale (mountainous Norway on the contrary gains 80% of its electricity from water dams, Sweden 50%)

2. Heat-pumps. The forces of nature (wind or water flows) bring ambient heat from basically unlimited areas to the cold side of the machine, that pumps it up to a higher temperature on its other, hot side and that can be used for heating homes. We thus did not have to do any work to collect the energy, only for pumping it up to a higher temperature and so the drive power is typically three times less than what we get out from the machine. In a practical sense the drive power is of no significance, because most of it comes out as useful heat also. These output temperatures are too low for the generation of electricity with present technology (very low efficiency), but for direct heating of homes, heat-pumps are infinitely superior to solar panels and wind-propellers for a year-around usage.

Last but not least, there is the very deceptive propagation of Hydrogen as an energy source.  Hydrogen does not occur in free form on Earth and is therefore NOT an energy source. On the contrary, much energy must be applied to extract free Hydrogen from it's natural chemical bonds, such as in water, which is the strongest bond of all. At best it can be used as an energy-converter (like in fuel cells) and always at (far) lower than 100% efficiency and only if the Hydrogen doesn't come from the electrolyses of water, in which case the "efficiency" becomes negative!

Those who argue differently, do not know what they are talking about, such as cars running on water only  - a violation of the First Law of Thermodynamics. That law doesn't say that energy cannot be produced or consumed (although people erroneously use those terms all the time), but instead that the same amount of energy that was applied to bring a system into an other condition, must be removed from that system to bring it back into the original condition and vice versa.

If there were any differenc , energy could appear out of nothing, or disappear into nothing. Hence, if you start with water and end with the same water, regardless what happened during the process in between, nothing was gained. If the Hydrogen however came from another source, like natural gases (Methane f.ex.), so the end condition of the process becomes different from the start condition, there can be a net-output, but the efficiency is almost the same as compared to combusting natural gas directly - a far more simple method. Now you know which e-books you should not buy, do you?