Parasitic Wind Turbine
Intro: Parasitic Wind Turbine
This was built as a lark, a whimsical attempt to recapture some of the hundreds of dollars I spend on air conditioning each year. It's a wind turbine powered by the compressor fan on my air conditioning unit.
But, It is a ponderable notion. And you could reverse the rotor, add a tail and yaw bearing and make a regular wind turbine.
But, It is a ponderable notion. And you could reverse the rotor, add a tail and yaw bearing and make a regular wind turbine.
STEP 1: The Alternator
I started off by messing around with a stepper motor I had, it was rated 6 volts 0.4 Amps per phase and was a two phase motor, meaning max input would be 4.8 watts. So running it backwards could I get that much out?
I'm not really an electronics guy, so I stuck my meter in AC mode across the terminals, spun it with my fingers, and got a reading of 50 volts! On current it read .2 amps. Umm okay, never mind the meter, would it light LEDs?
So wanting to see if it would light LEDs I wired 5 red LEDs together, four as a full wave bridge rectifier and the fifth as the load. As you can see in the video and pics, it had no problem lighting those LEDs, nor the five super bright white LEDs arranged in the same manner.
I'm not really an electronics guy, so I stuck my meter in AC mode across the terminals, spun it with my fingers, and got a reading of 50 volts! On current it read .2 amps. Umm okay, never mind the meter, would it light LEDs?
So wanting to see if it would light LEDs I wired 5 red LEDs together, four as a full wave bridge rectifier and the fifth as the load. As you can see in the video and pics, it had no problem lighting those LEDs, nor the five super bright white LEDs arranged in the same manner.
STEP 2: The Rotor
In the vein of keeping the design simple I wanted to have a simple rotor. My solution was to pull the blade assembly off of a cheap box fan that had reached the end of it's life. The rotor had been attached to the fan on a 1/2 inch shaft. To accommodate the 5mm shaft on my stepper motor, I press fitted a half inch dowel into the fan and then bored a 7/32nds hole through the dowel, and split the end of the dowel with a razor saw to allow the use of a hose clamp to secure the fan to the motor shaft.
STEP 3: Housing and Mount
The housing and mount are made from PVC, the housing is made from two 2" end caps, a 2"ring to align the caps and hold the motor in place and a 1/2" elbow cut down to attach the housing to the mount. The two end caps are held together with aluminum tape.
STEP 4: The Load
The load is a group of five LEDs per phase arranged as a full wave bridge with the fifth as the load. Instead of poorly drawn schematics, I suggest you read this wikipedia article. Here are some pix.
STEP 5: All That's Left
Is to place the motor mount onto the stand and place it on top of the compressor. adjust for best RPM and you are good to go. You might note that contrary to expectations, ie, that you could just set it on top in line with the fan, the best RPM comes from an offset 45 degree placement.
Addendum, I constructed a diode bridge with diodes salvaged with from a CFL and replaced one of the LED loads and recorded an open circuit voltage of 10 volts. Now here's a question for smarter people. Could I put the two phases in series for an OCV of 20 and charge a 12 volt battery?
Addendum, I constructed a diode bridge with diodes salvaged with from a CFL and replaced one of the LED loads and recorded an open circuit voltage of 10 volts. Now here's a question for smarter people. Could I put the two phases in series for an OCV of 20 and charge a 12 volt battery?
STEP 6: Acknowledgements
These persons are directly or indirectly responsible for this project.
William Kwamba for his inspiration
Alan Parekh who provided the LEDs.
and
The Reuk website for the info on steppers.
William Kwamba for his inspiration
Alan Parekh who provided the LEDs.
and
The Reuk website for the info on steppers.
STEP 7: Addendum
Not as neat as I'd like, but I bodgered up the turbine in conventional form for those who might be interested, alas Code Enforcement would be all over me if I actually installed a wind turbine.
PVC fittings
broom stick boom
road spam tail
and
bamboo stake for yaw bearing.
All held together with screws.
PVC fittings
broom stick boom
road spam tail
and
bamboo stake for yaw bearing.
All held together with screws.
143 Comments
ascento 13 years ago
rgerber1 8 years ago
I agree, I believe the unit is already loaded by " Sucking" air through the coils.. the fan appears high enough to not restrict the air flow out of the collar of the unit ( for lack of a better word, much like the back side of a house fan, at least on my ac unit it has a cone in which the fan sits slightly in front of)
mgalyean 10 years ago
toddk63 8 years ago
My thought exactly on adding resistance to the condenser motor. Spraying water on the condenser coils will certainly improve the system, but at the risk of leaving hard water deposits fouling the coils.
mgalyean 8 years ago
Hard water. Good point. Maybe I should have taken the condensate from the inside evaporator and sprayed that water instead as it should be much more scale free than tap water having lost the scale when it became humidity in the air.
javierkayaker 9 years ago
WERE DID U BOUGHT THE MOTOR??
Radiothermal 9 years ago
I stuck an old 140mm PC fan over my Trane unit and at best generated 4v at 20ma. Cool idea, I'm gonna build by own with a 200mm fan.
paqrat 12 years ago
I got the idea for using a fan when, a few years ago, I bought a small electric fan and walking to the car I noticed the breeze I was generating by walking slowly was spinning the blades of the fan.
nav_lexy 12 years ago
dangerous dan 12 years ago
I have some steppers laying-around, and your 'ible has got me thinkin'!!!
dangerous dan 12 years ago
TANSTAAFL
whitten_jaw 12 years ago
Z = -[j]/ [(omega)*(Capacitance) or Z = 1/[(omega)*(Cap)] < -90 degrees
and an inductor is
Z = [j]*(omega)*(inductance) or Z = (omega)*(Ind) < +90 degrees
kenmneth 13 years ago
SNUFFY3724 13 years ago
austinpowerzzzzz 13 years ago
dallasmel 14 years ago
You tap energy off a condensing unit, you'll get less energy out of your process, and increase the amount of energy the condenser uses. There's just no way around it! There's no such thing as 'free energy".
unclejoe 14 years ago
'honeybees can't fly per law of aerodynamics'
dm, the energy being tapped is the dump/waste heat energy. there is no strain on the condenserunit as it is designed to push air away from said unit to remove the excess temperature, aka cooling effect.
if anything. the small fan blade assists in moving the air by deflecting it.
===============
Callum Snowden 13 years ago
dallasmel 14 years ago
Not only does the condenser fan remove heat from the condenser via "forced convection", the system in which it operates is essentially fixed, and fan laws for a fixed system with turbulent flow applies. The change in air-horsepower as a function of a change in the system resistance of such flow (eg: more restrictive as a result of placing your device in the airstream) changes as a linear funciton if assuming constant mass flowrate.
Strain is a change in length over a unit length, and as a result of compression or tension of a member. Strain does not apply to a machine, in this case a heat pumping machine. You restrict airflow in a heat pumping machine, you will encounter an increase in the delta-Temperature (ie: leaving-entering air temperature) at a constant heat transfer rate according to a Sensible heat transfer (ie: another process).
The First, Second, and Third Laws of Thermodynamics apply to everything. There's no way you ... or a honeybee can get around it.
unclejoe 14 years ago
this device is utilizing the exhaust not the intake and was discussed
in the comments with trebuchet in june 2008. please read.