Wind power for off grid.

nobody928
nobody928 Solar Expert Posts: 62 ✭✭✭✭
I know wind power is expensive and solar is the way to go most the time over wind. However in my neck of the woods most of the time when it is cloudy and nasty outside wind seems to be very prevelant. I was wondering if wind would be a good balancing factor to recharge battery banks during inclimate weather intern causing the genset to run less. Does anybody use wind generators for this reasoning and how much would a decent set up cost in order to charge 400 ah worth of battery on a windy day?

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Wind power for off grid.

    That's very good reasoning. Unfortunately it comes up against the problems wind power always has:
    1). Is there really enough wind to make it worth the investment?
    2). Is the turbine you buy/build good enough quality to operate until you get your money's worth?

    All too often the answer to both questions is "no".

    So you need to know not only the average wind speed but also the gust peaks and how high up you'll need to place the turbine to be out of turbulent air. Then you need to find a turbine that won't fall apart. Or sometimes 'blow apart' - literally.

    As for how much you'd need for 400 Amp hours of battery that would depend on the Voltage of those batteries as well as the charge rate required (a bit different from solar since wind is available for more than 4 hours a day). Theoretically the wind input could negate the usage and keep the batteries charged rather than cycle them.

    Cost tend to be distressingly high, especially as the needed tower arrangement can be as expensive as the turbine itself or even more.

    On the other hand if you want a just few Watts as supplementary charging and don't care that you won't actually see the rating of the turbine and are perfectly willing to accept low efficiency it becomes easier.

    I discounted wind at my location due to the impossibility of the installation: the best location would have required a 50' tower built on a creek delta with several more trees cut down and guy-wires run out into the lake. That would not happen for so many reasons! All to get 300 Watts of power when the wind blew.

    And of course do not forget that if the batteries are charged you need some place to send that wind power all the time.
  • zoneblue
    zoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    Re: Wind power for off grid.

    As said above wind viability boils down above all to wind availabity. The relationship between power output and wind speed is deceptively non linear. And the reality is that some places are just a lot windier than your average place, and those are the places that make wind stack up, be it domestic or commercial scale. Unfortunately (or fortunately...) people tend not to live in those places.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Re: Wind power for off grid.

    I haven't yet repaired my 1kw wind turbine (siezed in February), it needs bearings again. It's yeild has been 650kwhrs per year for almost 10 years. 2.1kw of pv yeilds 2000 to 2200kwhrs per year. So, small wind is labour and maintenance intensive. PV isn't (unless you are tracking).

    Ralph
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
    Re: Wind power for off grid.
    nobody928 wrote: »
    I know wind power is expensive and solar is the way to go most the time over wind. However in my neck of the woods most of the time when it is cloudy and nasty outside wind seems to be very prevelant.

    "Neck of the woods" - bad sign. In general the lowest part of the rotor disk needs to be 30 feet above the nearest obstacle for 300 feet in any direction. High ridges work great; high plains work OK. Woods are harder because you have to be 40-50 feet above the tallest tree around.

    All that being said, if you are in a good wind area, and you don't mind the maintenance, they can work well. NREL has some good wind maps.
  • nobody928
    nobody928 Solar Expert Posts: 62 ✭✭✭✭
    Re: Wind power for off grid.

    Yep im in the tall pines I imagine my trusty generators are gonna be my best option. Wind sounded like a good idea in theory but I dont think it will be feasible.