SCIENCE & TECH BLOG
by Eliza Donavan
One of the precepts of physics is that all energy eventually turns into heat through entropy. Heat, other than the infrared heat that we are familiar with, is also molecular motion or vibration. We are all familiar with the term “global warming”, and we are also told it is due to burning fossil fuels and greenhouse gas emissions. This is partially correct, but not the whole story.
So let’s look at, as Paul Harvey used to say, the rest of the story. If we burn gasoline in an engine, and that engine is only 19% efficient (some haggle over the actual percentages, and say it is much higher), then 81% of the energy of combustion of the gasoline goes into the environment as heat without doing any useful work. For the sake of argument, let’s say the total energy we have to spend is 100 kilowatts of energy. Then 19 kilowatts of that goes to the wheels to move the vehicle, and 81 kilowatts goes into the environment as heat. How much is 81 kilowatts of heat? Well, one kilowatt is 3412 BTU, British thermal units. Those in America are familiar with BTU ratings for furnaces. 81 Kilowatts is equal to 276,372 BTU, or the output of a typical home furnace. Now, think of all the vehicles on the road—those in front of you, and those in back. Just one thousand is equal to over 276 million BTU, which is enough to heat a stadium or a large swimming pool. This is not looking at the greenhouse gases—just the heat generated by our vehicles and machines. But we have more cars on the road than that, don’t we? If we just take 200 million vehicles on the road on the planet as an example, which is actually a pretty conservative number, this figure comes to 6.824 x 1011 BTU—nearly a trillion BTU. This heat is injected into the environment, and the CO2 acts like a stopper in the bottle preventing it from leaving.
But it gets worse...far worse. You see, for every watt we put into the environment, we get 3.412 BTU of heat energy. Let’s look at power plants now (didn’t think I would let you off that easy, did you?) Let’s say we have a thousand megawatt plant. How efficient is the power plant? Let’s look at that one too. A typical nuclear reactor converts the heat of fission, which is a very wasteful way of producing heat in the first place (Einstein said it was a “helluva way to boil water.”) to steam. That steam goes to a turbine, which is about 30% efficient at converting the steam to mechanical energy to spin the shaft. It is attached to an alternator that is about 80% efficient. OK, so we can haggle over percentages, but on the average that is what we have to work with. Multiplying 0.3 times 0.8 gives us 0.24, or 24% efficiency. This is almost as bad as that gasoline engine earlier, but not by much. What this means is that 76% of the heat energy winds up going up the stack of the cooling towers. Didn’t you ever wonder how much heat those things put out? Let’s look at that to answer that question. If the power plant generates one billion watts, or 1000 megawatts, then roughly three times that amount goes up the stack as heat, or 3 billion watts of heat. Think of that space heater that you have in the corner of your office that takes 1000 watts, and multiply that times 3 MILLION. And that is just one reactor. The same applies to coal fired plants, with the exception that the mechanism for burning the coal is not 100% efficient, and you wind up with CO2 gas as a byproduct. OK, so part of the argument is that not all power plants put that heat into the atmosphere, and that goes into lakes, rivers and oceans. How do we calculate one BTU? Well, one BTU heats one pound of water 1 degree Fahrenheit. At 8 pounds to the gallon, it takes 8 BTU to heat a gallon of water 1 degree F. With the 3 billion watts example, we have just a little over 10 trillion BTU, which will heat 1.2 trillion gallons of water 1 degree PER HOUR. Just for reference, the Great Lakes are 6 quadrillion gallons, or 6 x 1015 gallons. With this example, just one power plant can raise the temp of the entire Great Lakes .00166 degrees per hour, but with slow convection currents we can see temp rises locally in the range of 2-5 degrees.
That is why we see things heating up. Our inefficient energy generation methodology created that heat, and the CO2 merely kept it from escaping. Those who do not know blame the CO2 for the heating. It’s really our own fault.
How do we mitigate this? Well, wind power generation is 80-85% efficient, so less winds up as heat on the generating side, but on the user side it still converts to heat. Solar is about 20% efficient, but newer collectors use the heat in the collectors to heat domestic water for showers and cleaning. Geothermal unfortunately is only 24% efficient if we use the same turbine and generator combo, but that is coming from the interior of the planet and not generating CO2 as a byproduct.
But what does it look like globally? Get ready for some really big numbers, and exponents to make your eyes glaze over. But here goes...according to the Shift Project Data Portal, the global electricity production is 2.2433 x 1016 watt hours, converting terawatts to exponents. Using the same average of efficiency, that comes to 2.29 x 1020 BTU, way past Carl Sagan’s “Billions and billions”. Actually, a billion billion is only 1018, less than a hundredth of that. That figure is enough to turn the 6 quadrillion gallons of the great lakes into a big cloud of steam. Thank goodness it is dumped into the entire volume of the oceans as a heat sink. But what does that mean?
ALERT...ALERT…exponents ahead! So how really big are the oceans? According to the source in Wikipedia, it is 332.5 million cubic miles or 3.32 x 108. Each cubic mile has 1.1 x 1012 gallons, or a total of 3.652 x 1020 gallons or 2.9216 x 1021 pounds of water. Once again, we take the BTU figure and divide that by the number of pounds to find the temperature increase. Yes, we are doing calorimetry on a planet! No problem! What do we get? It comes to .07 degrees F increase per hour. Now, most of this tends to get radiated away, and the temp increase that is left over winds up as 1.68 degrees temp rise. So what are the environmentalists claiming? A 2 degree temp rise. Do we see a correlation here? If we include the heat trapping of the CO2, that figure comes to 1.992 degrees temp rise...close enough.
So the big problem here is not so much the CO2, as the method of power production. The first problem is that we cannot continue to generate power the way we have been. It is horribly inefficient, and created this problem in the first place. Unless it is part of a larger agenda, which it could be, but for now we will not go there. For now let’s see if there is a solution to this problem.
There have been inventors in the past that claimed to have something called “cold electricity.” That is a type of electrical energy that winds up drawing heat out of the environment instead of increasing it. These inventors have been ruthlessly suppressed, and held the answer to this global problem. There is also something called the “heat trap” technology, which is essentially a method of turning infrared back into electricity, as a kind of infrared solar cell. That has been demonstrated, but has found a shocking lack of support. We can also generate power without boiling water, as that is so 19th century! (Albert Einstein was right!) Using the heat trap tech with solar panels can drive efficiencies close to 90%, as well as geothermal without circulating water or boiling anything. We have to use a different mindset than the one that created the problem, and think outside the box.
And finally, we have to ask the same question that Gerard O’Neill asked in The High Frontier: is the surface of a planet really a good place for a technological civilization? If not, then what the heck are we doing here? If the most energy intensive and polluting industries went off-world, would we see an increase in the quality of life and the environment? I think the answer is a resounding yes.
It is definitely something to consider.