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Let the Wind Howl by Chris Devaney

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The Repairs

The Air-X units, those fish-tail looking units near the crest of the roof, have been flying for over 6 and 5 years respectively.  The big green, 6-bladed Mallard on the lower south roof has been in service for 3 years.  So, being almost 7 years off the grid, I have some experience in dealing with the unexpected, the malfunctions, I’ve had direct contact with Mr.  Miserable, Malfunction-Murphy himself.  Here is a list of the repairs so far:

• Air-X, west side of roof: Burned out control circuit board 1st year of service, repaired under warranty by the factory. 

• Air-X, east side: Same thing, first year of service, circuit board replaced under warranty.  A replacement circuit board was sent to me free of charge from the factory with instructions on how to install it.  Oh boy!  I get to use tools.  Where might they be?

• Mallard 800E: In the 2nd year of service it suffered a bent hub, that’s the thing that secures the blades to the rotating shaft.  The hub was replaced with a new design, one that is stronger and lighter.  Cost: around 25 bucks, 28 bucks if you include new cheap Chinese replacement tools for the ones you can’t find, thirty bucks to include a can of shiny paint to match the rest of the unit.  Oh boy, once again, more roof-time.

• Replaced ALL rubber vibration isolating mounts on the mast, way more than once.  Eventually I changed them all to solid mounts with rubber spacers.  I only had to do that once, problem licked. 

• Air-X east side: Tossed its plastic nose cone in year 3.  Nose cone retrieved from the meadow and I epoxied the cracked cone then reinstalled it.  Two weeks later I had to fetch it again, same meadow, about the same distance away.  No more epoxy, it is now and forevermore running without a nose cone. 

• Air-X west: Blown fuse.  This is a very noticeable condition with the Air-X’s although it took me about 20 minutes of head scratching to figure out what was going on the first (and only) time it happened.  When a fuse in the Air-X blows, the unit will free-wheel and winds up to full speed, the internal speed control senses this and slams on the brake.  The brakes are nothing more than a feedback of generated current into the armature windings that creates an electro-magnetic drag on the rotor.  This slows the rotor and the brake releases.  Then, the unit spins itself crazy again until the brake once again slams it to a stop electro-magnetically.  This will go on and on unmercifully until you realize the fuse has blown and replace it.  To correct this, I put the stop switch between the Air-X and the fuse.  Now if the fuse blows, the stop switch can still be thrown to the closed position which shorts the windings and puts a drag on the rotor at all wind speeds. 
  
  The Mallard does not have the electronic brains like its sisters, the Air-X’s.  There is no automatic electronic braking feature.  I use a stop switch positioned between the fuse and the wind generator that will short the windings to create the drag.  Otherwise, without a stop switch positioned “upstream” of the fuse, the Mallard could spin itself to a violent death if the wind is strong enough. 

That’s it!  No other repairs, not even tune ups.  Well, no, that’s not true.  I did clamor up on the roof one more time to adjust the voltage control unit on the Air-X’s to the OFF position.  That was necessary after I installed a diversion load controller on the battery bank inside the house to take over the control functions.  Note that the Mallard does not have any circuit boards or control electronics in it’s housing.  A definite plus in my experience. 

Robust little things these little wind generators are, I must say, but if you are a tinkerer, it can be a dilemma.  There’s just nothing to do but sit, watch and listen to them sing ... all day long.  “No fix-ems”, they should call them.  My tools are rusty from repose... at least I suspect they are, I can’t find them since they are not on the roof where, according to my tool filing system, they should be. 

One other maintenance issue to be aware of is that in the winter, after a wet snow and cold windless night, the blades can ice up and not spin until the sun comes back out to melt the ice, generally the next day.  I have yet to climb up on the roof to de-ice the blades, a particularly treacherous thing to do on a metal roof in the winter. 

So, that’s it for maintenance.  Let’s talk about cost effectiveness. 

Bear in mind that I’m not a financial genius. 

Payback Time

Does is make sense to generate your own electricity?  Will it pay off in your lifetime?  It did for me.  Although my circumstances are a little unique, with the wind generators, the pay-back period was almost immediate and well in my favor. 

I’m often asked how long it took to break even on purchasing and setting up an off-grid facility.  The cost of a small (read that as very small) system like mine is relatively budget friendly: less than $600 each for the Air-X’s, $385 for the Mallard.  There’s additional costs of around $250 each unit for pipe, mounting hardware, wire, switches, gauges and other support equipment (like replacing lost tools), not counting the free labor... mine, or kids', if you can find them.  There’s also an inverter and batteries to consider and that could get expensive depending on your choices.  Miserly me took the cheap road during the learning phase, Wal-mart batteries (deep-cycle kind, about $60 each), 5 of them, and two 750 watt inverters for about $79 each.  I’ve added more items along the way but for the most part, the above represents a functional basic system that has worked well for me.

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