Thoughts on Large Scale Electrical Energy Production
1. Greenhouse Gases.
Carbon dioxide and methane are two of the most potent greenhouse gases. Like the glass of a greenhouse, they allow sunlight to reach the Earth's surface where heat energy is created. But they tend to inhibit the flow of such heat back into space. As their percentage in Earth’s atmosphere increases, accelerated global warming can be expected (and is indeed occurring). The combustion (or "oxidation") of "organic" molecules produces carbon dioxide. Each molecule of carbon dioxide consists of one carbon atom bonded to two oxygen atoms. Each molecule of methane consists of one carbon atom bonded to four hydrogen atoms. Methane is the simplest "organic" molecule. Much larger molecules can be formed by stringing methane atoms (and other atoms) into large, complex chains. Such chains are the building blocks of all plant and animal life.
Certain cells "breathe out" methane. At one time in Earth's early history such cells were far more prevalent than they are today. Volcanoes also exude methane (along with a host of other gases). Indeed some of the big organic (methane-containing) molecules found in life forms have been created in test tubes by passing sparks through methane. It is generally believed that these big, molecular precursors to life were formed in Earth's early history by lightning storms that raged around the planet ... a planet where volcanic activity was much more widespread than it is today, and whose atmosphere contained much higher concentrations of methane.
Methane hydrate can be described as methane in a quasi-"frozen" form. One or more methane atoms are typically trapped inside an envelope of water molecules. Methane hydrate exists in deep ocean depths. The near-freezing temperatures there, combined with great pressure, have resulted in vast deposits of this material in abyssal depths around the globe. Brought to the surface, the pressure and low temperatures that trap the methane within envelopes of water molecules vanishes, and the methane is released in gaseous form.
Methane is readily burned with the release of heat and carbon dioxide. Several energy companies and even governments are studying ways of "mining" methane hydrate from the sea floor. Methane is an even more potent greenhouse gas than carbon dioxide. Attempts to bring this material to the surface will inevitably be accompanied by "spills" … the release of raw methane into the atmosphere. This and the burning of methane will both result in an increase of two of the most potent greenhouse gases into the atmosphere.
2. "Green Energy": Hydrogen, Photovoltaics, Water and Wind Power.
"Green Power" is the generation of usable power without increasing the atmosphere's greenhouse gas content.
Photovoltaics (or solar panels) is a technology whereby sunlight is converted directly to electric power. There are no byproducts of any kind. (But the fabrication of these marvelous devices does produce certain toxic wastes.) There are vast tracts of land in the United States, the Middle East and Africa well-suited for huge "power farms" that utilize these devices. Of course they only work when the sun shines, and excess energy must be somehow stored for use at night and during cloudy times. A promising hybrid is "grid tie" photovoltaics. In these systems solar panels are typically placed on residential and business roof tops and supplement grid electric power during daylight hours. If enough solar panels are in use, the power produced can at times even exceed the power needs of the residence/business, and the excess energy can be pumped into the grid, typically making the electric meter run backwards! In effect some of the excess energy can be stored in the grid, and drawn back out at night and/or during cloudy days. In America the federal government and many state governments offer inducements for the installation of grid tie photovoltaic systems on individual residences and businesses.
Wind power is also a green source of energy, and has been used by mankind for many centuries. Like solar power, it cannot be turned on and off at will. It works only when the wind is blowing. Thus here again, methods of storing excess energy for use at other times must be employed. Wind turbines that drive electric generators (or "wind jennies") work best in non-turbulent or "laminar flow" air streams. Such laminar flow is typically not found at ground level and/or on roof tops; one must go higher. Thus wind jennies are usually most effective when mounted on towers. Towers in turn are often prohibited by Home Owner Associations and by municipal codes in densely populated areas. An advantage of wind turbines is that the mechanical power they produce can be directly used without conversion to electric power (with inevitable energy losses). Thus wind mills have long been used to grind grains, pump water from wells, drive looms in textile mills, etc. Some spectacular wind "farms," with literally hundreds of big wind turbines, are creating power from the wind today. And more are being planned. Having moving parts that are subject to wear and tear, the wind jennies on such wind farms typically require more monitoring and maintenance than solar panels.
Hydrogen is highly combustible and, like organic compounds, has been burned to create heat energy. Unlike solar panels and wind jennies, the burning of hydrogen results in a combustion byproduct. However, one of the most striking and attractive attributes of this gas is that the combustion byproduct is water vapor. In brief, hydrogen is not a greenhouse gas, and utilization of hydrogen as a fuel does not produce greenhouse gases. An important advantage of hydrogen is that it can be used to produce power on demand. One does not have to wait for the sun to shine or the wind to blow. The use of hydrogen is perhaps the least developed of the three green technologies discussed in this article.
Significant research into methods of "packaging" hydrogen in safe forms, for use in vehicles and other devices, has been performed to-date. A cylinder simply filled with high-pressure hydrogen is quite literally a small bomb that can create quite a blast (and perhaps fire) if cracked ... clearly a consideration in automobiles which can and do experience collisions. Liquefying the hydrogen and packaging the liquid in high pressure tanks, as is done with propane (LPG or Liquefied Propane Gas) is not practical. For It is much more difficult to liquefy hydrogen than larger-molecule gases like propane. One of the more promising approaches to "defusing" this situation is to force hydrogen atoms into the microscopic matrix of certain metal hydrides. Once in such a matrix the hydrogen atoms weakly bond to the metal hydride atoms and stay in place until "boiled out" by the application of modest heat (typically utilizing the byproduct heat created when the hydrogen is used to produce mechanical or electrical power). At this time hydrogen has been successfully used to power vehicles, space-heat buildings and generate electrical energy.
One of the more interesting "hydrogen engines" is the fuel cell. When this device is fed pure hydrogen, it becomes a sort of electric battery whose only byproducts are heat and water vapor. There are many excellent fuel cell articles on the internet. Some can be accessed via the links at the bottom of this page. Fuel cells are actually more efficient than internal combustion engines, and are high on the R&D lists of many governments and research organizations.
3. Nature’s Oxygen/Carbon Dioxide Partnership.
In its early years, Earth’s atmosphere contained very little oxygen. For over a billion years anaerobic (non-oxygen-using) single-cell organisms were the dominant life forms. In time, however, life forms that excrete oxygen as a biological byproduct began to proliferate. And as these cells became more dominant, the oxygen in Earth’s atmosphere began to rise. This in turn resulted in the emergence of cells that take in oxygen and excrete carbon dioxide. Broadly speaking, today it is the plants that take in carbon dioxide and excrete oxygen, and the animals that take in oxygen and excrete carbon dioxide. This cycle is fundamental to virtually the entire eukaryotic community, which includes the plant and animal kingdoms. (It is also vital to many species of aerobic prokaryotes, primarily bacteria.)
Today the largest land-based producers of oxygen are the rain forests of South America (particularly Venezuela and Brazil). This resource is being "slashed and burned" at an alarming rate in order to create agricultural land. Like practically all forms of combustion, slash-and-burn pumps additional carbon dioxide into the atmosphere. And as this canopy of oxygen-producing plants is decimated, the oxygen-producing half of nature’s oxygen/carbon dioxide partnership is negatively impacted. Fortunately a large part of nature’s oxygen production occurs in the oceans, which are populated by enormous masses of single-celled plants. However, even here there is evidence that the concentrations of ocean plant life may be on the wane.
Add the decline of oxygen-producers to the growing amount of carbon dioxide being added to Earth’s atmosphere by mankind’s carbon compound combustion in vehicles, power plants, slash-and-burn, etc. and the prospects are disquieting. Any "green" method of producing energy is clearly worth studying.
4. Hydrogen Production.
Hydrogen is one of the most abundant elements on the Earth’s surface. Virtually every molecule of water contains two hydrogen atoms and one oxygen atom. Water molecules are non-combustible. However, if the hydrogen and oxygen atoms of a water molecule are separated, then they will recombine (or "burn") with the release of heat energy. Such heat energy can then be used to drive turbines and generate electric power, among other things.
Of course there is "no free lunch." In order to separate a water molecule’s hydrogen and oxygen atoms, energy must be put in. One method of separating the hydrogen from the oxygen is electrolysis. Electrolysis utilizes significant amounts of electrical energy … the quantities typically produced by nuclear power plants.
5. Nuclear Power Generation.
Relatively enormous amounts of heat energy can be realized by splitting the nuclei of heavy elements such as uranium. The process of converting this heat energy to electrical energy is straightforward. However, there are two problems with this method of producing electrical energy. First, the "fuel" and the byproducts of the process are highly radioactive. Radioactive elements and compounds release gamma radiation that can be hazardous and even lethal to life. Accidents at nuclear power generation facilities are inevitable, and the potential for a release of such materials into the atmosphere is ever-present. The results can be devastating, as was the case with the "meltdown" of a Chernobyl reactor in the former Soviet Union.
Even if such accidents do not occur, the second problem of how to store the byproducts of nuclear reactors continues to challenge technology. Some of these byproducts are very "hot," and remain so for hundreds or even thousands of years. In a nutshell, minimizing leaks from nuclear power generation facilities is only half the problem. Safely protecting the "biosphere" from these byproducts for centuries and even eons is equally challenging.
The good news is that nuclear fission does not produce greenhouse gases. Radon gas is, however, a byproduct and (like the other hot byproducts) must not be released into the atmosphere.
6. Nuclear Fusion.
The flip side (so to speak) of nuclear fission is nuclear fusion. Whereas nuclear fission entails the splitting of large atomic nuclei, fusion entails the joining of the smallest nuclei into larger ones. Interestingly enough, this process is also accompanied with large energy releases. Indeed fusion is the process whereby the stars produce their prodigious amounts of energy.
The fusion process requires that two atomic nuclei be brought sufficiently close that the short-range, attractive nuclear forces engage. Once such proximity has been accomplished, the nuclei "snap" together with the release of energy. But there is a catch to getting such nuclei adequately close to one another. Since all atomic nuclei are positively charged, they ordinarily repel one another. These repulsive forces must be overcome if two nuclei are to be brought close enough together for fusion to occur. The repulsive forces are not trivial. The late physicist Richard Feynman used a dime to illustrate. If all the (positively charged) nuclei of a dime could somehow be isolated from all the negatively charged electrons, and if these positive charges could somehow be held together in two "super" nuclei, then at a separation of one meter (or about one yard) the force repelling them apart would be greater than the weight of the Rock of Gibraltar. It would be greater than the weight of the Himalayas. It would be greater than the weight of all the water in all the world’s oceans. It would equal the weight of the entire Earth!
How do the stars do it? The answer is that, owing to the enormous amount of matter in a star, stellar gravitational fields are tremendously greater than those of planets like Earth. Despite the very large speeds of a star’s material particles (great heat amounts to great particle speeds), the enormous gravitational fields contain them to the volume of space occupied by the star. Under such conditions such super-speed particles on collision courses regularly get close enough together (before slowing to a halt) for the short-range nuclear forces to engage and for fusion to occur.
Such fabulous gravitational fields do not exist on Earth, but other means of containing the molecules of "super-hot" plasmas long enough for fusion to occur have been investigated for quite some time. Unhappily progress has been slow, and only limited success has been attained. The only terrestrial cases of fusion power have been thermonuclear (or "hydrogen") bombs!
At present, then, the splitting of large nuclei (nuclear fission) is the only effective, earth-bound way of harvesting the enormous energies locked in atomic nuclei. But locating nuclear power plants close to populated areas always entails risk. Any method of removing fission power generation facilities far from inhabited lands would seem to be a step in the right direction. Safely disposing of the "hot" waste would still be problematic. But considering the production of greenhouse gases that inevitably accompany the burning of organic fuels, many consider such hot waste to be the lesser of two evils. Some have advocated expelling the stuff from Earth in big rockets! They might be right.
Pykrete is quite simply water, laced with sawdust or wood slurry, and frozen. It has amazing properties, including a staunchly reduced rate of melting and resistance to impact damage. Pykrete was discovered by Geoffrey Pyke (hardly a household name) during WW2. Large blocks of the stuff can easily be produced at water’s edge, slid into the water, and fastened into any size floating platform with tie rods. Being ice, it of course floats.
Even in rough seas the ride on a large enough "island" of pykrete would be quite smooth owing to the island’s great mass. It would be comparable to the ride on a large iceberg … pleasantly smooth even in choppy seas. The scant amount of research on floating pykrete has shown that its very slow rate of melting can be all but halted completely by very modest refrigeration (using embedded tubes).
Anchored pykrete islands might provide platforms for large nuclear power plants at sea, far removed from inhabited dry land. And the prodigious electrical power that can be generated by a nuclear power plant can be used for the electrolysis of seawater and the production of hydrogen (with the byproduct, released into the atmosphere, being oxygen).
8. Hydrogen Distribution.
Production of vast quantities of hydrogen from seawater is of course only part of the big picture. Assuming nuclear power plants, afloat on pykrete islands, were used to generate the hydrogen, the hydrogen must still be distributed to end users.
Several schemes come to mind for getting the hydrogen from its pykrete island points of origin to dry land. Large, flexible tubes could be tethered below the sea’s surface (away from the turbulent waters stirred up by storms, and well below the keels of surface ships). The hydrogen produced at sea could thence be pumped to shore facilities. Another possibility would be huge bags, filled with hydrogen and pulled by seafaring tugs from the pykrete islands to shore facilities. Even dirigibles could be used, either self-propelled or also tethered to tugs. Once at shore’s edge, the hydrogen could be pumped out and replaced with air for the return trip. (Dirigibles might be floated back to the pykrete island production sites).
Perhaps the least problematic leg of the distribution chain would be on dry land. Huge networks of gas distribution pipes are already in place, many originating from shore facilities. As the economy shifts from natural gas/propane to hydrogen, such pipelines could be suitably modified and re-allocated to hydrogen distribution.
9. Concluding Remarks.
There is gold in seawater! Like hydrogen extraction, isolating such gold requires lots of electrical power … the kind produced by nuclear power generation facilities. It isn’t altogether far-fetched to conjecture that the gold produced on floating pykrete islands would pretty much pay the overhead. It might even place the American dollar back on a gold standard. True enough, there isn’t much gold in a cubic meter of seawater. But the supply is virtually limitless, and the plants would be running 24/7. To paraphrase the late Everett Dirksen, "20 tons here, 50 tons there … pretty soon you’re talking real money!"
It might come as something of a surprise that more hasn’t already been done with Pykrete. Suffice it to say that this amazing stuff has been around for over half a century and is available to virtually any organization or country for making ships of any size and for creating additional living and/or agricultural space at sea (not to mention providing remote sites for nuclear power generation facilities).
The world is in crisis and tilting toward an epic global warming disaster. The byproduct of burning hydrogen is water vapor! The byproduct of water electrolysis is oxygen! Does combustion get any better? We can easily produce the pykrete in unlimited amounts. We have the nuclear know how to build reactors … reactors that wouldn’t require all of the built-in safeguards of shore based facilities. We have the technology to use hydrogen for powering vehicles, space heating … you name it. What will it take to get us off the dime? Hopefully not extinction. Notwithstanding the contempt so many feel for Chicken Little, the prospect of such a global disaster is not out of the question. It’s happened more than once in Earth’s history! Chances are if it happens again, we’ll have no one to blame but ourselves.
References and More Links.