Hey I’ve been thinking quite a bit about alternative energy and it seems to me that there are three really big possibilities ahead: solar, wind, and nuclear. I wasn’t really too big on wind so much because of its intermittent nature where it’s economical.
So it got me thinking a little bit. And I noticed that the power output from a wind turbine is jointly proportional to the area (or the radius squared) of the imaginary disc swept out by the blades as well as the cube of the wind speed.
The cube of the wind speed is what really got my attention because if the wind speed were greater, say, by a factor of 3, then you could get an equal power output with a much smaller blade radius (and hence area), thus reducing material costs.
But the problem is, wind speeds are variable even where the average wind speeds are high enough to justify wind power investment over alternatives (such as solar), or over the status quo.
But what if you set up a controlled environment in which you produce winds that are really fast, and unchanging with time? I looked up how fast a leafblower blasts out air, and I found that leafblowers that are run-of-the-mill and can be purchased at a home improvement store blow out wind at an adjustable speed between 140 and 270 mph. Now there’s a wind turbine with a blade diameter of 154 feet located in the Palm Springs area where the average wind speed is 18 mph.
Making a calculation gives that a wind turbine exposed to a speed of 270 mph, to produce the same power as the average power produced by the wind turbine in Palm Springs just mentioned, would only need to be 2.65 feet in diameter. That’s quite a bit bigger than a leafblower’s tube diameter, but only by a factor of 5 or so. And a leafblower uses very little power, obviously, compared to that wind turbine’s output.
Increasing the area of the leafblower’s “blowing tube” to 3 feet would certainly not increase its power usage to that equal to the power generated by a wind turbine encased inside its tube with diameter 2.65 feet and wind speed generated of 270 mph, which would produce a power output of equal to a wind turbine whose blade is 154 feet wide (each turbine in the Palm Springs location generates an average of 25 kW; the total 4,000 turbines generate an average power of 100 MW).
I am pretty sure the continuous operation of a wind tunnel/leaf blower kind of tool to generate the high winds is certainly not going to be close to 25 kW for a cylindrical tube only 3 feet in diameter. (When I said “leafblower,” I don’t mean literally one…=) I just mean something that generates high winds of any desired and high speed. Wind tunnel would be a better description; it’s obvious that wind tunnels can generate speeds as fast as jet planes travel; some 500 mph at least).
Do you think it’s a reasonable idea to not just accept whatever wind the environment provides, but rather, create an artificial wind of extremely high and steady speed, thus consuming power, but using that high wind speed to decrease the size of the turbine yet still get a reasonable amount of power output that exceeds the power input to generate that wind? Also, the wind doesn’t completely have to be artificially generated. An input wind can be funneled through some corridor or engineered structure that by virtue of its geometry, increases the local wind speed.
I have a feeling that this violates one of the laws of thermodynamics though.
