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Wind Genny at Miller Farm

The Plan

Overall design:

  • Loose the batteries and the charge controller, simpler system with just an inverter, grid disconnect, and bi-directional meter and base.
  • Slightly larger turbine, say 1-1.5 kW.
  • Charge controller integrated with turbine.

Design changes:

  • Larger conduit, 4", from tower to the side of the house/utility interconnect.
  • Conduit path will be re-marked to avoid existing buried cables with one turn.
  • 48V?, recalculate conductor size, do we need to use #3?
  • When we pull the conductors we should also pull shielded twisted pair for data.
  • Large enough house side enclosure to also accommodate a charge controller if we decide to add one later.


  • Poured 8" x 36" posts with anchor bolts embedded to attach turnbuckles to.
  • Anchors on tower ~24" from base for turnbuckles.
  • Collar at the top to hold the turbine mounting shaft, braced 1/3 and 2/3 of the way down from the top.
  • Consider guy wires.

Swift Turbine:

Other turbines we considered:


  • Consider the battery powered lawn mower bit that Phil Seybold told us about.

Design Notes - March 30th, 2009

  • We are using the MW-200 with a max output of 7A at 50MPH.
  • #4 conductor from tower to house to be under NEC 3% loss guidelines at 24V.
  • 2" schedule 40 PVC conduit buried between the tower and the house.
  • Need information from Wes on trenching. Lee Higgs will do the work, we need to mark the path.
  • Call 800-382-5544 to have them mark the known utilities.
  • Conduit is buried and covered as the trench is dug, 90 degree elbows turned-up at each end.
  • Single door enclosure that flips up or down, probably down, with the picture mounted on the inside of it.


Shopping List

(Charlie has a copy of the parts list that RP&L generated from this. They are willing to support some amount of the purchase price, I can't remember the number now but Mic should.)

1. 130 foot 6AWG NMC power cable

   $300.00 at (theirs are single conductor, we'd need at least two)
   or 4x 130ft 12AWG NMC outdoor power cable = $395.60 at Lowes
   2x 50' 1/2" aluminum conduit = $34.44

2. Duplicates of the Dennis Outback equipment

    PDFs are here:
    Prices here:

unfortunately it seems that the flexmax charge controllers are designed for solar arrays and are not compatible with a wind source. Here's why: Granted the risk of blowing out a charge controller on our genny would probably not be of grave concern (it would take 50mph winds to get our genny to do above 7 amps on a 24VDC system), do we still take the risk given that the warranty and service won't cover it? MacroWind sells inverters and controllers that are compatible it seems with solar PV input. Randy from Third Sun thinks this to be the simplest way to handle our problem, however he did mention that using a step up converter, integrating wind into the system we have in Dennis is possible so perhaps it would be with the Farm. We need to have a separate controller for each application though but not necessarily a separate inverter.

3. Batteries

15202, the sealed AGM is closest to what we have in Dennis but 15210, the Gel battery, would give us better value. We'd need some multiple of 2 of them at any rate.

4. Enclosure The dimensions we need to work around are roughly 12x8x16 for the inverter, 15x4x7 for the solar charge controller and 6x6x10 for the wind charge controller

This will fit at least those three components, but probably not much else:

This would be extra roomy:

Here's the closest I've found There's no price list but they can come plenty big. I'll work on trying to match more precisely what we need. Closest Distributer is Reco in Indianapolis: 5610 W. 73rd St. Indianapolis Indiana 46278 Phone: (317) 297-9000

5. circuit box and fuses.

  • we already have an outdoor circuit box with extra space inside. Depending on what it's already connected to we could hijack it for alternative purposes