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Ask Slashdot: Can FOSS Help In the Fight Against Climate Change?
dryriver writes: Before I ask my question, there already is free and open-source software (FOSS) for wind turbine design and simulation called QBlade. It lets you calculate turbine blade performance using nothing more than a computer and appears compatible with Xfoil as well. But consider this: the ultimate, most efficient and most real-world usable and widely deployable wind turbine rotor may not have traditional "blades" or "foils" at all, but may be a non-propeller-like, complex and possibly rather strange looking three-dimensional rotor of the sort that only a 3D printer could prototype easily. It may be on a vertical or horizontal axis. It may have air flowing through canals in its non-traditional structure, rather than just around it. Nobody really knows what this "ultimate wind turbine rotor" may look like.
The easiest way to find such a rotor might be through machine-learning. You get an algorithm to create complex non-traditional 3D rotor shapes, simulate their behavior in wind, and then mutate the design, simulate again, and get a machine learning algorithm to learn what sort of mutations lead to a better performing 3D rotor. In theory, enough iterations -- perhaps millions or more -- should eventually lead to the "ultimate rotor" or something closer to it than what is used in wind turbines today. Is this something FOSS developers could tackle, or is this task too complex for non-commercial software? The real world impact of such a FOSS project could be that far better wind turbines can be designed, manufactured and deployed than currently exist, and the fight against climate change becomes more effective; the better your wind turbines perform, and the more usable they are, the more of a fighting chance humanity has to do something against climate change. Could FOSS achieve this?
The easiest way to find such a rotor might be through machine-learning. You get an algorithm to create complex non-traditional 3D rotor shapes, simulate their behavior in wind, and then mutate the design, simulate again, and get a machine learning algorithm to learn what sort of mutations lead to a better performing 3D rotor. In theory, enough iterations -- perhaps millions or more -- should eventually lead to the "ultimate rotor" or something closer to it than what is used in wind turbines today. Is this something FOSS developers could tackle, or is this task too complex for non-commercial software? The real world impact of such a FOSS project could be that far better wind turbines can be designed, manufactured and deployed than currently exist, and the fight against climate change becomes more effective; the better your wind turbines perform, and the more usable they are, the more of a fighting chance humanity has to do something against climate change. Could FOSS achieve this?
Hmm, Germany is on 100% renewables now, so that argument kind of backfired on you.
1. Germany is no where close to 100% renewable energy.
2. East Germany switched to capitalism 30 years ago.
3. Even today the ex-communist east is is dirtier per euro of GDP than the west.
The whole point of a carbon tax is:
Energy != Fossil Fuels
There are other ways we can harness solar energy, and geothermal energy. Our addiction to the drug of cheap fossil fuels is preventing us from getting to those other ways fast enough.
Where are we going and why are we in a handbasket?
The current rate of warming is about 50 times higher than any warming cycle detected in the geologic record.
So if we attribute the typical Milankovitch Cycle warming rate to be caused by natural orbital change, that would leave another 98% of the warming to be attributed to other, non-Milankovitch causes. Such as man-made global warming.
--- Often in error; never in doubt!
There is no point in hunting for a more efficient rotor design for two reasons:
1) The current designs are so near perfect efficiency that there's little to be gained for a lot of effort.
2) Efficiency of the rotor, once it's "good enough" is not a big deal. When your "fuel is free" except for the cost of the equipment to collect it, the significant measures of efficiency become "power per dollar spent on equipment" and "energy per dollar spent on maintenance and site and equipment amortization".
As with the carnot limit on how much of the energy in heat can be extracted by a heat engine, there is a theoretical limit to how much of the kinetic energy you can extract from the air (or other compressible fluid) passing through a given swept area. It is called the "Betz limit". It is16/27ths, about 59.3%. It occurs because extracting energy from the wind slows it down, reducing the amount of air passing through the mill. It works like the laffer curve in tax rates: If you take no energy as the wind passes by, you get no energy. If you take all the energy you stop the wind, so you get no energy. Somewhere between there's a percentage of extraction that gets you the maximum. For wind, that's 16/27ths.
As you approach the Betz limit you reach a point of diminisihing returns. You can throw progressively larger amounts of money into the design of your mill to get progressively smaller amounts of additional energy. Or you can spend a little extra money to just make your mill a little bigger, which lets it sweep a lot more area and collect a lot more energy.
Modern 3-bladed horizontal-axis wind turbines (HAWTs), running at a tip speed ratio in the 6 to 7 range, get within a few percent of Betz perfection. (Higher TSR would get you a little more, but above 6 you're starting to get to where a storm could make the airflow near the tips go supersonic, which is a problem structurally.) Scaling them up gives you more power per unit cost, so the utility mills converged to giant 3-blade HAWTs.
Horizontal axis because vertical axis designs tend to be either FAR less efficient or have terrible issues with vibration (though the helical darrius seems practical for small mills). The main advantage of a VAWT over a HAWT for small (i.e. off-grid residential/farm/small business) mills is that HAWTs need to be made to track the wind but "furled" in a high wind to avoid damage, which makes them more complex and failure prone. (HAWTs may need furling, too, but they don't need tracking and they're easier to overbuild to reduce the need for furling).
Three blade because one blade (like a maple leaf) and two-blade have vibration problems when yawing to face a changing wind. Three or more do not. More blades don't buy you any extra efficIency so three is the least expensive to build.
If you want to improve wind turbines you'd do well to concentrate on less expensive construction methods, rather than trying to chase the tiny amount of efficiency that's left.
If you want to improve other aspects of renewable energy, there's more room for improvement in control, storage, photovoltaic designs, direct collection of heat, and cooling (including radiative coupling to the four-degree kelvin cosmic background temperature through the "infrared window").
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way