WindyNation 35 in. blades & a Presto Alternator 80 rpm

Discussion in 'Post Your Photos' started by murray2paddles, Aug 26, 2009.

  1. murray2paddles

    murray2paddles WindyNation Engineer

    Finally was able to find the time to build and raise another tower. This one I have chosen to erect on a higher rock ridge behind the house. It collects prevailing winds a little better due to its location than the Leeson 180V .

    It is on a 32 ft. tower. First 21 ft. section is 2 in. with the remaining tower top @ 1/12 in. pipe.
    Presto suggests using a clamp type on their alternator shaft which is showed on their web site. I never used this ( so it might work ok ) but I wanted the shaft to be under load right from the bearing so I placed a spacer on the shaft so it would be loaded and not allow any shaft play. I was not really sure if the Presto was going to be able to withstand the weather so I also built a fiberglass / carbon cowling to protect it.

    Due to being on the rock ridge this meant once again drilling holes into the granite rock and epoxied my rock bolts for the guy wires. With the higher tower this also requires two sets of guy wires. The lower one stabilizes the tower and the top set is the one that takes all the force. I have a gin pole that I use to help raise and lower this tower. My son ( the hulk) has been my power on raising and lowering but now that he has left to return to the city life I will have to change over to a winch type set up to raise and lower. ( I will show how this works in the tower change write up to the Leeson 180 V which I will post soon)

    The only other thing I will make a change on for this tower will be the cable used for raising, at the moment it is 3/16 in , it is probably ok but due to the investment I want to be sure so I will change this cable to 1/4 in.

    You might notice on the tail section there will be a small wire hanging. This is a very light 1/8 in. wire with a small carabiner on the bottom. I use this to manually move and secure the position of the alternator/ blade unit when lowering if there is a wind blowing. I have also used it to take the unit out of wind when there was a huge storm and I did not yet have the top guy wires attached, this worked perfectly. I also discovered that with this small wire it showed me how much my unit had turned with changing wind and creating a twisted power wire inside the pole. Very easy to walk up and spin the alternator back to a neutural position again. I do not expect this to happen often but this summer we have experienced weather patterns so out of the ordinary so who knows what the future weather will bring.

    NOW, the Presto alternator which is advertised to give 12 V at 80 rpm I believe is true to its advertisement. I am also very pleased with the WindyNation 35in blades. They start picking up wind at about 2 mph. @ I have cut in at approx. 3 to 5 mph. I can't believe how quiet they are in a 12 to 15 mph wind. I am looking forward to see how everything works when it is storm time and we have our gal type wind.

    At the moment I am sending this hydro back down to the shop while the Leeson is down for tower changes. When this is finished I will be directing the power from this Presto / WindyNation tower into the house and connecting to plug and play inverters. I elected not to set up a battery bank in the house. My house back up power will come from the shop tower. I will have more info on the inverters shortly and will post for everyone.

    If I have forgotten anything I am sure you will let me know by asking. May the wind blow your way.

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  2. murray2paddles

    murray2paddles WindyNation Engineer

    Sorry, I don't know how to edit a submitted article SO.... when I stated I have a light 1/8 in wire hanging from the tail section, that should read 1/16 in wire.
  3. murray2paddles

    murray2paddles WindyNation Engineer

    Well we got hit by the big wind I was waiting for and more. We experienced what is called a micro cell within a gale force storm. The tower held its own up until the micro burst and then it was so sever it bent the top section between the two sets of guy wires. We believe this happened possible due to the extreme lift the blades were able to produce. Since then we have now strengthened that pole by straightening the top 1 1/2 in section and putting a 2 in pole over it as a sleeve.

    Now the part that is very interesting and possibly disappointing. The bend might have been produced due to the tremendous lift power of the 35 in blades. Observing the actions of the unit in light wind as stated in the first report, it did pick up light wind very fast and as the alternator add stated it was producing cut in power very fast. BUT as many of us do not read all the fine print and we are lured by the adds that a generator can produce 12 V at relatively low rmp. we must learn to look into the rest of the formula.
    If you look at the Presto Power Curve advertisements the look impressive.
    As an example it states : 800 rpm - 97 V * 8 amps = 776 Watt, the rpm. volts and watts look pretty decent and appealing.
    But a first hint should have been the low amps reading.

    Now the formula, when the add states 97 V. this does not apply to most of us who are using a 12 V system.
    So now if you use the Oms formula, I will also give you a link so you can easily use this for your own calculations

    For us this should read : 800 rpm - 12 V * 8 amps = 96 Watt
    Yes that is right, only 96 watt and 800 rpm is a good spin for any generator.
    So my verdict is in due to this finding. Had I known this I would not have purchased the Presto !!!!!!

    Now the next part of the learning curve. We matched this alternator up with 35 in. blades and when in light to moderate winds the unit is able to hold itself facing the true wind. If the wind increases the unit continually tries to move and stall and then must seek true wind once again. We believe the blades may be overpowering the unit as there is very little load ( amps ) to put the blades under a work load. When there is a high wind condition this also creates an undesirable sound from the blades due to spinning so fast with no resistance.
    What did we learn, We believe we have matched the wrong generator to the right blades.
    It is really important to match your blades to suggested load power of your unit and not just seek out fast pick up and fast cut in.
    We are still looking at solutions to the noise issue and if we continue, a follow up will be given.
    As an end result I believe the Presto should / will be replaced with a different unit that will deliver realistic watts / amps under load.


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  4. murray2paddles

    murray2paddles WindyNation Engineer

    Presto down and WinbBlue up

    The next step in matching blades to power units had us move from the 80 in wind grabbers to the 5 blade Turbo Torque. At last it ran quiet in Winds 10 mp and up. These blades did not overpower the unit by sending it out of true wind when picking up stronger ( gusts) winds. It was a good match, but again the Presto was only capable of producing approx. 100 to 125 watt in 12 to 15 mph winds.

    The WINDBLUE alternator was the next test. Down came the Presto and fortunately the cowling built for it fit perfectly over the new WindBlue. Same hub with the Turbo Torque 5 blade set and up it went. The alternator had an advertised start up of 150 rmp to reach 12 V.. & again another manufacturer that was true to its advertisement.

    The easy part to this write up will be " it was no different than the Presto" , Same Results in the wind. Near the same amount of watts being produced as the Presto.

    If you were looking for a power unit that trickle charges or you only have a need for low wattage, both the Presto and the WindBlue proved to be very reliable alternators and preformed well. Matching the correct blades is always important for both of these units and to the amount of available wind in your area. I recommend the 5 blade Turbo's due to real time testing. I think it would be interesting to step it up to the Hyper Spin but not having tested them, just can't tell you anything in real time.

    Now I will be looking for the next power unit to test and in my quest find a power unit that we are all in need of, Something that gives us reasonable watt / amps to sit atop our towers.
  5. timber

    timber WindyNation Engineer

    Thanks for the "real world" reviews of the units and in particular, how well the WindyNation blades performed.
    Sorry to hear that your tower bent but it's all part of the learning curve, I guess.
    I'm getting closer to sailing my new Windtura 500 with 35" Windgrabber blades and am glad to hear that they do so well at low wind speeds.
    We have tall firs on our lot and nearby so we take what we can get from the gusts, under currents and occasional sustainable winds here.
    Late fall and winter produce some worthy results, even with a 21' tilt-up. (There's no way we can get higher than the trees on our lot but it's nice to be able to harvest some of what mother nature dishes out.
    Thanks for sharing your experiences with us.

  6. murray2paddles

    murray2paddles WindyNation Engineer

    Hey there timber. some neat stuff you are posting. If you haven't checked it out yet. go to Generators and look under New 500 Furling and Power
    This will give you an idea on what is possible for your new 500


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