wind powered heater

wild01wild01 Solar Expert Posts: 97 ✭✭✭
Ok, this is just my random thought of the day... fair warning

I live in an area that gets extreme wind somewhat randomly. my house is fairly well insulated, but during the wind storms there is no practical way to really keep my house warm, I use wood heat and when the wind picks up it just sucks the heat out of the house and burns the wood uot of the stove at a rather impressive rate.

lately as I've been lying in bed feeling the house shake, a thought popped into my head, what if i put in a 3 phase 400volt wind generator and hooked it directly to a 3 phase electric heater like this one

no fancy charge controllers, no super heavy wires, no battery, no mess, just heat when I need it.

thoughts? comments?

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: wind powered heater

    Here's a thought:

    If when the wind blows it sucks the heat out of your house there's something wrong with your house.

    Here's another one:

    If you use that wind to generate heat, that heat will also just be sucked out of your house.

    In short, you've got to identify the heat-loss problem and solve that, not just add more and more heat to be lost.

    Here's a comment:

    This is not unique to your situation. It is in fact the whole energy crisis thing in a nutshell; waste can not be solved by throwing away more.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: wind powered heater

    Here is one solution,,,

    Where we used to live the 1880's farm house would go through wood like there was no tomorrow, in spite of blowing in cellulous in the walls. Eventually we yanked off the siding, installed 2" of thermax (polyiso board) on the outside, with taped joints, covered that with Tyvek, and the heat loss went down by orders of magnitude.

    Remember, you have two issues, first is heat loss to which insulation will help, and the second, and perhaps most important is infiltration. Every Cu Ft of air that comes in, replaces a Cu ft that you have already paid to heat. Some old houses have dozens of air changes per hour, if not more.

    The combination of Thermax and Tyvek on the outside cut down on both the heat loss, but most importantly they cut down on the infiltration dramatically. Old houses are very difficult to seal without major work.

    For the same money you invest in wind or Pv to "heat" the house, you would be way further ahead to reduce the heat loss.

    Tony
  • Truth SquadTruth Squad Solar Expert Posts: 126 ✭✭
    Re: wind powered heater

    People were always wanting to do this with Air 403 turbines. The key to that is an unregulated turbine with a charge controller and use the heater as a dump load. But to hook directly to that heater, I seem to recall you're going to need an unregulated turbine.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: wind powered heater

    air infiltration is the problem, but you need some of that air to run the wood burner (fresh air) or it would not burn. i don't think the wind turbine is the answer either as that heat would also be sucked out. you may need to rethink how you heat if your present system is not working well for you. sealed fireplaces or stoves that have vented air from the outside into it while sealing up the house better with better insulation may do the trick. it's either something on this order or keep getting lots of firewood.
  • peterakopeterako Solar Expert Posts: 144 ✭✭
    Re: wind powered heater

    To make 15 KW from a wind turbine you need a big wind generator. If you have that money spare....:confused: a Proven 15KW plus tower is between $80.000,- and $100.000,-

    What if the termostat is switching of the heating during a storm.
    Your wind generator will be free wheeling , there are some nice videos from free wheeling wind generators and not one is standing after that.
    Yes i am aware about the self control from the proven wind generators but it needs still a loading and in this case it will be full load or no load.

    that brings me to the next problem by low or avg. wind conditions the loading is so high that the wind turbine is in Stall.

    or are you making aspecial controler to control all this as well

    Greetings from Greece8)
  • wild01wild01 Solar Expert Posts: 97 ✭✭✭
    Re: wind powered heater

    Ok. I should come to expect this from this site after a while. It seems that everyone here looks at any problem solely from an unskilled consumer mindset. First off my house is already about as wind proof as it can be made. It was double housewrapped inside and out when it was built, the problem is when the wind is blowing at 50-75mph THERE IS NO SUCH THING AS ENOUGH INSULATION!!!!!

    now as to the other problems I am not looking at purchasing a wind turbine. the main thing that makes retail wind turbines so expensive it that they have to be integrated into either the grid or a battery + inverter system. what I'm looking at is BUILDING a turbine based around a 3 phase 15kva self exciting alternator (much like what is used in a rotary phase converter) which run from 500-1000 dollars.
    putting it on a 30ft tower(5"schedule 40 iron pipe), guying it at 18 ft, attaching 20ft homemade blades (10ft per blade) either gear or pulley drive it to get the proper rpm Direct wiring it into the 15kva heater w/o a thermostat (logic being if the wind is blowing hard enough to overcome the turbine stall, I'll need heat) and let it run. i figure 2-3k for the whole system.

    the only problems i foresee is whether the intermittent voltage will mess up the fan in the heater and setting up a breaker that will short all 3 legs of the motor together if/when it throws, so the turbine doesn't overspeed.
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: wind powered heater

    You could make this project a lot cheaper by using alternator from old gas generator in 4 - 6 KW range. Make smaller blades, about 4 feet each so that there is less loading on your tower at 70 MPH winds. I think its better to have 3 smaller wind turbines versus one 20' diameter one when you have winds this high. Also think what will happen if motor to blade connection fails (chain breaks) at high winds, how will you stop the turbine? What if one blade detaches, can it hit your house or someone? Since you want to generate power at very high winds, you may not want your turbine to furl. In that case, the machine has to withstand any wind speed that your location can produce. Because of that, I am thinking small blades made out of thick aluminum sheet. You want to over engineer the part where blades connect together, because heavy aluminum blade thrown at high rpm can fly far and be deadly.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: wind powered heater

    Wild1,

    I have no doubt that one could build such a device, but it seems like for the time and trouble there might be some better solutions. I just tend to be a proponent (in general) to do everything one can do for conservation. I know full well what 60-80 mph winds can do to the heating load of a building. At a minimum, a blower door test will reveal air leaks one can't even begin to see, regardless of how much house wrap.

    Tony

    PS I get it now 'coot!
  • wild01wild01 Solar Expert Posts: 97 ✭✭✭
    Re: wind powered heater
    AntronX wrote: »
    You could make this project a lot cheaper by using alternator from old gas generator in 4 - 6 KW range. Make smaller blades, about 4 feet each so that there is less loading on your tower at 70 MPH winds. I think its better to have 3 smaller wind turbines versus one 20' diameter one when you have winds this high. Also think what will happen if motor to blade connection fails (chain breaks) at high winds, how will you stop the turbine? What if one blade detaches, can it hit your house or someone? Since you want to generate power at very high winds, you may not want your turbine to furl. In that case, the machine has to withstand any wind speed that your location can produce. Because of that, I am thinking small blades made out of thick aluminum sheet. You want to over engineer the part where blades connect together, because heavy aluminum blade thrown at high rpm can fly far and be deadly.

    hey thanks for the constructive criticism. Good point about the blade drive failure, now that I think about it, gear reduction is probably the only way to go, also I'll need to engineer a centrifugal brake on the blades. I figured to engineer it to only turn about 200 rpm max. i do plan on putting in a furling system, but only for extremely high winds 80+mph

    as far as 3 smaller turbines, while the idea appeals to me, available power goes up exponentially with blade diameter, so 3 10ft turbines would not equal 1 20 ft. I'm hoping to just keep everything turning slow enough to minimize the centrifical forces on the blades, good point on the aluminum, that's got me thinking about pipe blades. I could use aluminum tubing like other people use pvc for the small scale home builts
  • peterakopeterako Solar Expert Posts: 144 ✭✭
    Re: wind powered heater

    Sorry to be negative but i prefere to keep board members alive.:D

    Even at 200 rpm the tip speed from big blades ( long ) is sub sonic. you are realy greating problems. and for a 15 KW generator only the magnets will be above 3000$.
    I h:Doop that you read more and rethink the setup.

    Greetings from Greece8)
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: wind powered heater

    peterako makes an interesting point, You must keep the tip speed under the speed of sound! Otherwise, you setup a stress point and they will crack. A tip coming off at the speed of sound can do one heck of a lot of damage!
  • peterakopeterako Solar Expert Posts: 144 ✭✭
    Re: wind powered heater

    I made a calculation on wind speed and power production, it is a long calculation so i show only the results.
    10 mph = 200 W , 15 mph = 400 w , 20 mph = 2000 w , 25 mph = 3600 w , 30 mph = 6200 w , 35 mph = 10000 w , 40 mph = 15500 W.
    This based on your blade size 10 Feet and using Blitz limit 55% and 15% mechnical loosing.

    So yes you can produce 15 KW but by a wind speed above 35mph.
    By 35 mph you must keep in mind that the blade squre feet from 100 is producing extrem force on the tower and supporting cables.

    Make a estimation from your blade weight and calculate ( check internet for newton gravity force).
    In my case i calculated that my whisper 200 full power running thegravity force from the tip is putting a force from 480KG on the fixing bolts in the hub.:roll:
    if during a storm the wind is changing (wind gust) the weight is 3 times higer for a moment.
    I have seen my tower ( a very strong setup) flexing from the top that makes you think twice to stay close by. and steel cables for support ( for lifting 2500KG) stretsing a few meters.

    All home made setup fail in a storm because of bad planning. sketch re think and calculate.


    Greetings from Greece8)
  • peterakopeterako Solar Expert Posts: 144 ✭✭
    Re: wind powered heater

    to audredger.
    It is not the tip that brakes but the force from the tip transferd to the fixing on the hub. that means that the compleet blade brakes free.:grr
    I found a blade from a whisper 100 setup around 200 meters from the tower after a lightening strike during a storm. the remaing parts whitout balance broke down the tower if it wash made from paper.

    wind power and high wind/ storm is not a good combination. try to drive your car full speed and take fast turns it does not work . it is the same force and bigger for windpower on a high tower.

    Greetings from Greece;)
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: wind powered heater

    I fully agree with Peterako. Building large turbine for the first time combined with very high wind is bad idea. It's best to start small, Air-X size small, to get experience.
  • KevinbKevinb Solar Expert Posts: 26
    Re: wind powered heater

    Wild01, have you posted your idea on the otherpower forum? Pretty much everyone there builds their own and you should be able to get some good advice. No offense to any members here, but this forum is really more about bashing wind power than encouraging it..usually for good reason. I also think you're shooting for too large a rotor diameter- that's pretty scary and not necessary in the high winds you're talking about. Good luck.
  • audredgeraudredger Solar Expert Posts: 272 ✭✭
    Re: wind powered heater

    peterako,
    I'm thinking back to the first model of the C-130 .. had a long narrow propeller. In over speed conditions a crack would develop within the last 4". This was the area of transonic flight. I don't doubt you statement of breaking at the hub. I wonder though, if the transonic flight sets up a flutter? Wind turbine blades are less stiff than airplane propellers. Where ever they chose to break, transonic flight is bad for propellers be they on airplanes, helicopters or wind turbines!
  • peterakopeterako Solar Expert Posts: 144 ✭✭
    Re: wind powered heater

    audredger:
    You are right but there the use is differend there it makes wind by a wind generator it is using wind to make power. ;) by a wind generator the blade is flexing more and this tension is ending to the root. a bad design wind generator is or wearing out angle of atack is to strong and it is running more than 8 times the wind speed or the material is to weak and the forces during high wind turbilens brakes the blade at the root.

    kevinb:
    I am also using the otherpower forum and i can tel you that as soon as sombody post there using high wind as heating power there respons ( incl. me ) is the same.
    I am not agains wind power it is producing 85% of my power. but i try to alert people about the dangers special in high wind areas. In my area a bad desing or installation is not working after 3 months.:roll:

    Greetings from Greece 8)
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