guidoLaMoto

Ancient thread, but interested people may enjoy this https://www.lowtechmagazine.com/compressed-air/ It's an interesting parlor trick, but until they repeal The 2nd Law of Thermodynamics, it isn't really very energy efficient, and there are engineering & safety issues involved in storing and using that compressed air in traffic.... ...but it's still nice to dream.

That's the mistake in logic always made in these sorts of calculations. You're trying to find a constant of proportionality to equate the KE of the wind with the output of the generator...But it's really the wind speed vs rpm that's important in generating the juice. The coils & magnets "want to know" what's the angular velocity of the rotating shaft, not how many Joules the fluid is carrying. The Coefficient of Power is really more of a measure of efficiency of turning fluid KE into electrical energy, but wind is free...so who cares about efficiency? Eg--(making up numbers for illustration)-- a flow of molasses may be traveling at x m/s with a KE of X Joules, while a flow of benzene may also have a KE of X Joules, but will be moving at y m/s, where x <<< y. A turbine exposed to the molasses will generate much less power than one exposed to the benzene. The generated power is directly related to rpms and only indirectly to KE.

Good point, Boon-- Case in point- Concerned about energy security when it comes to winter heating, I have a wood burning boiler system, but it requires two electric circulating pumps and a small brain box. I need about 1.5kW/d to run it. Here in WI, even without Alzheimer's, it's easy to forget what the sun looks like over the five month heating season, so solar is cost prohibitive....I figured I could afford to gamble $375 on a 1200W turbine from Walmart. It arrived with a one sheet set of directions. Unfortunately, my Mandarin is a little weak, so I winged it-- no way to contact anybody about questions or clarifications. It came equipped with a charge controller, which one would assume not only protected from over-charging on the high end, but would also contain a charge booster for the low end of output so batteries could be charged when the wind was not ripping at the rate 27mph-- which, unless you happen to live on Mount Washington-- is probably the more usual situation....It would have been nice if the jerks had warned about that and mentioned that an aftermarket charge controller with boost capability may help. I have a 1200W/12V vertical, lantern style mill...Does anybody know if a gizmo like this https://zhcsolar.com/product/wind-turbine-mppt-charge-controller/ will solve my problem?