A recent article on Arstechnica got me thinking about alternative energy. Pardon the pun in the title: “joules” are units of energy, not jewels (though jewels have alot of joules). In as much as some of us may think the world will end before we run out of fuel, there is a chance that it won’t, and we’ll be forced to utilize other sources of energy (unless, of course, you don’t mind giving up your air-conditioning, amongst all those other benefits that come with power and a functioning economy).
We know for certain that solar power will always be available, at least until the sun explodes, but at that point, we’ll have bigger problems. Here’s an interesting thought for those of you who think humanity will be around forever: scientists speculate that the universe will end in heat death, or at least they did until someone discovered you could use Brownian motion to get power. (Interestingly enough, if energy harvesting like this was scaled, it might defy the Second Law of Thermodynamics (hint: it concerns entropy), or more accurately, some people’s interpretation of it.) If the Second Law of Thermo does hold true, then heat death it certain. Nevermind the fact that the countdown to heat death is billions of times longer than the current age of the universe according to promoters of macro-evolution (and you thought 100 billion years was a big number). I think the sun-exploding is a more pressing issue. Or rather, let’s get back to oil running out.
Distant future generations are going to have to think about alternative energy, and they’re going to hope that we laid a good foundation.
What options do we have for energy sources? The following list lays out the most common:
This includes both nuclear fission and nuclear fussion. Fission energy (what we usually think of when we speak of “nuclear energy”) is created by collecting the heat from the non-critical radioactive decay of heavy elements. Layman’s explanation: Big atoms can’t hold together, so hitting them with a neutron makes them fall apart quickly and release energy. The heat warms water and spins a generator as it cools. This is similar to how steam engines work, and this sort of tactic will probably be applied to collecting heat from fusion. Fussion is the combining of two elements to a more stable, larger element. Every nucleus (atomic center) wants to be like iron. Hydrogen releases the most energy in when it fuses with another hydrogen atom, but in order to combine, they must be close enough for this mysterious nuclear force to take effect (or get stronger) and pull the nuclei together stronger than the electromagnetic force can push them away. That takes alot of energy. The sun uses fusion to create energy, but the hydrogen atoms have to be combined by extreme pressures, which happen to be created by the sun’s gravity. Incidentally, it is possible to accomplish nuclear fusion by making a device in your garage in your spare time (as Mark Suppes, Thiago Olsen, and Carl Greninger & students did). It wouldn’t be efficiently, but it would get you into graduate school in nuclear physics really easily. With hydrogen fusion, the by product is helium (sweet! More balloons!) Nuclear fission, on the other hand, leaves radioactive waste. Why not use the waste? It’s not powerful enough to be worth it, but it won’t finish decaying for years. Nevertheless, you can encase the waste in graphite and bury it in your backyard: the graphite around the waste decays at a much slower pace (only a multi-billion year half-life, from what I’ve been told).
On a related note: Having been influenced by this episode of Star Trek, I once dreamed of creating a biological organism that would “eat” radioactive material and live on it. *sigh* Oh the days when I had all the answers to life!
It spits smoke, therefore it must be bad, right? There’s more in coal than just charcoal. The primary byproduct (assuming this is a fairly clean burning) is carbon dioxide, a harmless molecule you will find everywhere (including your drinking water). If only that was the only thing that came out! Then we wouldn’t need filters on our power plants.
The catalytic converter on the back of your car converts the poisonous byproduct of burning gas, carbon monoxide, into carbon dioxide. We have alot of gas, not just oil. A cattle ranch can provide the power for a nearby neighborhood just from the gas from cow manure. The New York Times says it’s been done. That’s one solution from the farm side, unlike ethanol, which requires 1.5 gallons of gas per gallon of ethanol produced, depending on the method you use (and assuming you start with corn). Of course, you could use living cells.
You’ve probably seen enough wind turbines to now have that associated with eco-friendly energy in your mind. Incidentally, “eco” is short for ecology. While “clean”, turbines do kill alot of birds. People were considering putting up a giant parasail or funnel in the gaps between mountains. At the center would be a wind turbine to catch the wind trying to travel through the gaps. There are several problems with this. For example, nature lovers would both be upset by how it ruins the scenery and the fact that it would act as an animal net that would suck unwary birds into its turbines (unless they are properly protected, but that makes the turbines alittle less efficient. Do we mind?). A better idea is to create an artificial tornado (pardon the cuing of the sarcasm). How would this work? Several generators in a circle would create a vortex (see side picture). Once the twister was created, they would reverse roles and start collecting energy. The idea was proposed by researchers in Canada. Assuming there aren’t many birds in Canada, that might be the ideal location.
“Hydro” his is short for “water”, not just hydrogen (which, as an energy source, fits under several categories). Dam up rivers, throw buoys on the ocean, or put it in vehicle gas tanks. We have several oceans, so it’s not like we’re going to run out. The problem is primarily harvesting that energy. Currently, the most energy can be gained by combining hydrogen gas with oxygen in order to make water. This is due to the strong electronegativity of oxygen. That same aspect of oxygen is utilized in biological cells to power them. The origin of cellular energy is ultimately the sun, and process starts when plants create it. Thus, that leads to solar power as being the primary energy source. Interestingly enough, water and sunlight work together very frequently in nature to provide energy, which brings me to the next paragraph:
You may be familiar by now with solar panels, but what about how they work? It turns out, typical silicon solar panels collect only 3% of all sunlight, meaning they are horribly inefficient, at least they were until the invention of carbon nano-tube structures for coating the silicon surface (Wikipedia info here). A prospect I found interesting was parabolic solar panels. The basic idea: several mirror concentrate light on a tube of water. The heated water then spins a generator (sound familiar?). Once again, water working with sunlight to provide energy.
Then there are some really creative wacko ideas that nevertheless have great potential. Aside from the Brownian motion idea mentioned above, there is the idea of artificially creating and controlling lightning. It is entirely possible, but it requires more energy than you put it. In order to get more output than input, nature would have to provide the clouds. If you think it’s still worth it, set up several huge capacitors and a radio tower in your back yard.
One final category is geothermal, but if you go that route, I don’t want anyone to be causing volcanoes.
That’s my overview of the generic energy sources. Obviously, we have quite a few options (some good, some not so much). It’s not like we have to pick one energy source specifically, though putting your eggs in one basket does make things easier.