Blogs, Energy Efficiency, Grid Scale, Hydropower, Wind Power

Compressed Air as an Alternative Energy

With the technology we have available today, we can power our homes and businesses from a small shed in the backyard on on a rooftop.

 

Companies offer ready-made LARGE DC Air compressors already mounted to a tank, with an air pressure switch. These compressors usually have 120 psi – 200 psi working pressures, and are rated around 20 amps DC @ 12V. These are heavy-duty compressors that are designed to be mounted on vehicles and used for suspensions and to make big trucks horns sound like a train.

 

Mechanics use the force found in compressed air everyday to power their tools, no reason that same force can’t be used to spin an alternator. Alternators and generators produce torque as loads are added. Most car alternators need about 1200-2100 rpm to “turn on.” Car manufacturers usually use a 2:1 or 3:1 ratio to allow the alternator enough rpm at idle (most vehicles about 800 rpm) to remain charging while at a stop.

 

Alternators need speed in order to become self-sustaining, and maintain the systems voltage as loads like lights, wipers, defroster, etc…, are added or dropped. your cars battery isn’t charged in cycles of near flat to fully-charged like generator systems are. If the coil wire isn’t connected to the battery, there is no emf within the alternator at start-up.

 

Increased speed = decreased torque

 

If I mount two 26″ bicycle rims side by side on a single axle through a pillow block bearing, I can use a small metal pipe with the end pinched, to spin both rims. By properly positioning my nozzle (pelton blade) I get the most from the high-pressure air being released. Once enough air is released fromk the tank, the air pressure switch kicks on the compressor for usually 1 1/2 minutes to restore the pressure in the tank.

 

Run a belt around the second rim in order to use it as a pulley to spin the alternator. From a 26″ rim down to a 3″ pulley, is better than an 8:1 ratio. In order for me to spin my bicyle rims at 800 rpm, I need just under 10 lbs of force at the rim. If I use 4 nozzles, that becomes a little over 2 lbs of force.

 

If I release compressed air from my tank at 90 psi and roughly 4 cfm, that is equal to 29.92 gpm @ 207′ drop or head for hydro. I doubt I need that much force to spin a couple of bicycle rims with an alternator attached. My over an 8:1 ratio means that as air is released to spin the rims at 800 rpm, I get almost 7000 rpm at the alternator.

 

The compressor and an inverter can be attached to the same battery that the alternator is charging, provided the inverter doesn’t exceed the load when the compressor kicks on. Using a 56V (48V nominal) DC alternator would allow you to charge a large battery pack for a 48VDC-120/240VAC system to power your house.

 

As a bonus, the air can be filtered as it enters the system, thereby actually cleaning our air as they power our homes and businesses.

 

Please feel free to contact me at [email protected] with any questions or comments.