Tag: Thermodynamics

You Can’t Fool Mother Nature

evenabrokenclock10Leave a comment

When I entered this world, in the mid-1950’s, the earth held about 2.7 billion people. This is the wondrous time people are calling for the US to return to, since we were “great” then. As of today, we are nearing and may have gone over 8 billion people on this planet. Unfortunately, the rules that were possible with a population of 2.7 billion, become unmanageable when there are 8 billion people on the planet.

Just think of the issues we face now which were not problems in the mid-1950’s. We now face many existential crises, and even still face the one we thought we had put behind us, that of nuclear conflict. The seas are becoming deserts as huge trawlers scrape all living creatures into their maws. The lungs of the planet are now succumbing to clear-cutting and soybean cultivation in Brasil, led by a mad-man who refuses to acknowledge the limits of our planet. In the US, population pressures in distant lands have led to an unstoppable tide of those wishing to claim refugee status within our borders. And everywhere we suffer from the natural byproduct of civilization, that is carbon dioxide, along with a refusal by many to believe in the laws of thermodynamics. So be it. Those who claim college educations are worthless deserve to come up against the inexorable power of nature, and suffer the inevitable horrible consequences. All that is left is for those of us who are educated to say “I told you so”. A poor response to deal with the human carnage set to come when the effects of global warming become more pronounced.

In so many ways, we are dealing with national governments which refuse to take a holistic view of the world situation. So many folks still believe we live in a world with only 2.5 billion people, rather than the real world which holds 8 billion humans. Whether it is the retrograde Republicans in the US, or the near-sighted populists of Brasil, or the newly-minted electoral majority in Italy trying to channel Mussolini, political movements across the globe are imitating flightless birds sticking their heads in the sand. By refusing to admit the world has changed, they are subjecting their followers towards the inevitable crisis as they drive their car off of the mesa and do a swan dive towards the ground below. So where do we find those who are really trying to deal with the problems of the present which will make our future untenable?

First, we must begin to listen to those of us who are screaming about physical limits inherent on the earth. There are certainly folks who recognize limits to systems on the earth, though their voices seem swallowed up by those who preach the gospel of prosperity. Many people renounced the mantra of bigger is better, and have gone towards a more sustainable lifestyle. Back in the 1970’s, those folks were characterized as tree-huggers, since they advocated and lived a simplistic lifestyle off of the grid. Now it is possible to be off-the-grid, yet still be connected to the world through solar cells. Yet we still see those new subdivisions built in places never intended to house large numbers of humans, places where the first unpleasant reality is a lack of water. A small encouraging sign has appeared in states like Arizona and Nevada. There legislation was enacted which removes the abilities of Home Owner Associations to require grass lawns. Note there is nothing that requires a more sensible landscape for desert cities, just that people may not be compelled to use immense quantities of water to maintain grass. I am quite certain that those who opt out of a green lawn still may face peer pressure to keep up their conspicuous consumption of water, and their spigots turned on.

If we are having to fight for common sense through legislative actions even for a resource as limited and as visible as water, what hope do we have in convincing large segments of the population to repudiate ongoing use of fossil fuels? Well, we can try to educate. At least some people may be convincible, especially since the world is changing in more visible ways. People look at fossil fuels as being the only effective sources of energy for humanity. But those who claim that do not have a clue that any combustion process has a thermodynamic limitation of efficiency. No combustion process can have an efficiency much greater than 50% due to the laws of nature. Therefore, in all combustion processes, whether an internal combustion engine used for transportation, or a steam power plant, fully half or more of the energy of combustion gets transformed into waste heat. Maybe you can harness some of that waste heat for other human needs, but that costs additional money, and is seldom used on a year-round basis.

Renewable energy is decried for being unreliable and diffuse, and requiring energy storage devices in order to ensure energy availability when needed. Maybe so, but an electron generated from a solar cell does not have the same thermodynamic limitation as energy from fossil fuels. And when it is produced at the same location as it is consumed, transmission losses become minimal. Only the inverter loss (about 10-20%) represents energy lost from solar cells vs. 50% from combustion. So solar energy has a head start on other energy sources used in mass plants and then distributed.

Wind energy is truly variable, and at the scale it is built at, either large energy storage systems are required, or alternative sources of energy aimed at load leveling are required in order to take advantage of this energy source. Once more though, electrons produced through wind energy are fully available to the electrical grid after going through an inverter.

Yes, but fossil fuels are macho! That seems to be the argument underpinning many of those who champion continued and unlimited use of fossil fuels. I don’t know about you, but climbing up some of those 300’ towers to service a windmill seems macho enough to me. Fossil fuels are somehow viewed as our right to use, regardless of any ill effects. Well, it seems we now know it is not a good thing to rejigger our atmosphere and reintroduce all of the carbon sequestered over the millions of years in a blink of a geological eye. But to those who say, we were given dominion over this planet, I say, I agree. And it is about time we use what we have learned to prevent a giant bollocks while we still have time.

Of Thermodynamics, and Sealing Wax, and Other Fancy Stuff

evenabrokenclock10Leave a comment
Power plant cooling towers venting waste heat

The gauntlet has been thrown down. The US needs to cut their carbon dioxide emissions by 50% by 2030, starting with a baseline of 2005. In order to accomplish this, real changes in the US economy must occur, along with some sacrifice by US citizens. And, the entrenched interests in continuing the status quo (energy companies, Republicans, utility providers) must be convinced of the necessity of this extreme action. Pretty difficult to do especially since the Republicans have made it their brand to not only dismiss the need for change, but they have proudly waved the banner of climate change hoax / no science to refute the claims of climate scientists. They have waved these banners for generations, and their influence will not go away, especially at the state and local levels.

First, it is necessary to present some simplified discussions of thermodynamics. This is the branch of physics which describes the limits nature imposes upon humanity. The first item needing description is black body radiation. Simply put, it means a body will emit radiation which puts it at equilibrium with the incoming radiation. Any disruption that affects the radiation balance will affect the equilibrium temperature. In our case, radiation from the earth is dispersed into the coldness of space. One is most aware of this phenomena on cold clear nights, but still above the freezing point of water, where frost forms on surfaces that are exposed to the vastness of space. Like, your car windshield which requires scraping when there’s no frost anywhere else.

The increase in carbon dioxide concentration (CO2) in the atmosphere affects this radiation balance. Put simply, CO2 absorbs some of the radiation that is escaping to space, and re-radiates it in all directions. The fraction that is radiated back to earth is radiation that increases the total amount of radiation earth normally receives. It increases the equilibrium temperature of earth, which is global warming. Since CO2 happens to absorb radiation in a range normal atmospheric components do not absorb, this means that CO2 exerts an outsized influence even though it is a minimal component of the atmosphere. Those who say that a small amount of this gas cannot affect the temperature of the globe are ignorant of basic physics and mathematics.

There is a second aspect of thermodynamics that comes into play with fossil fuels. That is the limitation in the amount of useful work that can be extracted from a high-energy fluid. All large-scale power plants depend upon a heat source (burning fossil fuels, nuclear fission, burning biomaterials) to heat and vaporize water to form steam. It is the steam that turns the turbines and results in the generation of electricity. Well, thermodynamics imposes a limit of about 50% peak efficiency for this type of power plant. You’ll have to trust me on this figure, since understanding and calculating the Carnot system efficiency is a staple of college engineering and science courses. There’s only so much explanation you can put into a blog post.

This says that whenever you have a concentrated source of energy being converted to another type of energy (combustion of fuel to electricity), you only get about 50% of the useful energy as an output. The rest is wasted as heat. Any time you convert one type of energy to another, there are losses involved. So why are folks so convinced that renewable energy sources are so necessary? One reason is that the conversion losses from solar and wind energy are much less than from a standard power plant. In the case of solar electricity, there is also much more potential for locating the power generation at the point of consumption. This reduces transmission losses.

The problems with renewable energy production? It’s variable. In the case of solar, it is guaranteed to not produce at least half of the time due to earth’s rotation. In the case of wind, it is at the mercy of the wind. Therefore, you need to either supplement renewables with a concentrated source of production, or you need efficient means of energy storage. While progress in energy storage is impressive, it is still expensive to use either battery storage or capacitors to bridge the gap between availability of renewable energy and consumption of that energy. The second problem with renewables is that you are depending upon a diffuse source of energy. The sun only shines so hard, and even wind turbines can’t compare to the energy density of a classical fossil fuel source.

The other problem with renewables is that they allow the consumer to bypass the utilities and the fossil fuel companies for some of the energy demand. While the prospect of going off the grid is extolled as an ideal, it is not practical for most people. We still need an energy infrastructure to cover those times when energy is required to supplement locally produced electrons. It is expensive to maintain and improve this grid, and what we’ve seen, especially with Texas, is that the grid can fail catastrophically if it is not maintained. So as much as we might want to be rid of giant monopolies governing our energy supplies, we need to construct a future system where they play a role, or else their looming obsolescence will cause them to resist any needed changes.

In my state of West Virginia, we’ve been in denial about the future of coal ever since I moved here in 1986. Coal was the exclusive source of electricity in this state for decades. Only with the increase in natural gas availability due to fracking did anyone in this state seriously doubt the moral goodness of coal, and of those who mined it. So we have suffered as local communities were shattered by the blasting needed to support mountain top removal. This form of mining only employed a small fraction of the workforce needed for an underground mine, but when it is all you know, you put up with a lot. We now have many acres of once pristine woodland and hillside covered in scrub grasses, devoid of topsoil, and unable to sustain much life. Such places would be ideal for solar farms, and slowly this state seems to be growing aware of this possibility.

West Virginia has suffered population loss for decades, ever since the coal mines first became mechanized. What better way to offer hope to the youth who now succumb to opioids than to provide jobs in solar energy? Education to enable people to learn the basics of electrical installations would raise the general education levels in this state. We must resist the siren song of reversing coal’s decline, and embrace the trend towards renewable energy that is the wave of the future. No matter what the Republicans say.