Electrical fan to power ALT

mikefloridamikeflorida Registered Users Posts: 5
Im new to this so here goes. To get started in this would it pay off to use a Electrical fan to turn the alternator to provide amps to your battery bank till you can afford the solor pannels and would this work? Any help on this would be helpfull. :-)

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Electrical fan to power ALT

    I take it your intent was to spin a wind turbine with air blown by a fan? Not likely to work at all.
    The losses involved going from AC to fan motor to alternator to DC are ridiculous.
    If you've got a source of AC power to run the fan, you've got power to run a battery charger. Get a good battery charger, as you're going to need some sort of back-up charging system for bad days when the sun doesn't shine and the wind doesn't blow.

    Example of good battery chargers: http://store.solar-electric.com/bach1.html

    If you're planning an inverter set-up, consider a more expensive model with built-in battery charger.

    BTW, on the whole small-scale wind power isn't very practical so don't expect much from it. Read our host's own disclaimer here: http://store.solar-electric.com/wind.html
  • mikefloridamikeflorida Registered Users Posts: 5
    Re: Electrical fan to power ALT

    No the fan will turn the alternator to charge the batt. this will simulate the vert turbin / solar pannels when they become aval to me. And yes a charger will be needed. I am looking at the options for useing less electrical power to reduce my electrical bill. Right now i use a gen set when we loose power from a bad storm.. Miami Fl. i am very new to this as you can see from my first question.

    thanks Mike
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: Electrical fan to power ALT

    Are you asking if you can take the blades of the fan and install them on the alternator? or are you asking if you can plug the fan in and point it towards a wind turbine?
  • BB.BB. Super Moderators, Administrators Posts: 32,013 admin
    Re: Electrical fan to power ALT

    You can make your own wind turbine... A good place to start is:

    www.OtherPower.com

    If you do anything less (such as blades on an automotive alternator mounted on your roof)--is going to generate next to nothing in the way of useful power.

    The other issue with home made wind turbines is that you should have a way to manage high winds and/or electrical failure (open winding/diodes/blown fuse or breaker, etc.)... The "standard" horizontal wind turbine, if designed correctly and collects power in 10-30 MPH winds--will self destruct in high winds and/or when the electrical side fails (no load on alternator will cause turbine to over-speed and self destruct).

    To "play the tape"...

    Conservation--your best way to save power and money. Using less, turning things off, new energy star lights, appliances, home heating and airconditioning, weather stripping, double pane windows, lots of ceiling insulation, etc.... Is almost always a better investment than any solar RE project (unless you are off-grid with a genset).

    Next, solar thermal... Good return on money invested. And can be done pretty nicely with "home brew".

    Solar Grid Tied (solar panels connected to GT inverter that turns your meter backwards) with state and federal tax credits can make sense.

    Anything else (off-grid, wind power, etc.) should be used "to save money" only after all of the above steps have been looked at first.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mikefloridamikeflorida Registered Users Posts: 5
    Re: Electrical fan to power ALT

    BB thanks for the info...

    let me start over.. the fan motor will turn the alternator or gen to power the unit inside.. not blow the turbin or the blades on the alternator.. eco bulbs already in use. Lights off when not in use.. The AC and ceiling fans i think are my proublem. is this clearer now

    thanks Mike
  • BB.BB. Super Moderators, Administrators Posts: 32,013 admin
    Re: Electrical fan to power ALT

    Mike,

    If you are thinking about attaching an alternator to an existing motor (say a simple house fan) and use the "extra power" from the motor to generate "free" electricity?

    Assuming that I have it correct... The answer is there are always energy conversion losses... And unless you work really hard at it (i.e., multiple engineers designing such a system)--you would be very lucky to have a 50% loss in the conversion...

    So, if you want 30 amps from the alternator, or 12v*30a=360Watts -- You would have to "buy from the utility" 720 watts of 120 VAC power to generate the 360 watts of 12 volt power out the alternator.

    I guess you are in Florida (I know--I am good! ;) )... Your probably best off stuffing insulation in your ceiling (if older home), looking at a new, high SEER, AC system. And you can even look at generating "free" hot water from your AC system by using a desuperheater (use the waste heat to generate your hot water). Shading windows and roofs with landscaping can help too.

    Also, reducing heat sources in your home (many people use filament bulbs in the ceiling fans--several hundred watts of heat there). Looking at other heat sources (people with several desktop computers, printers, etc.) also generate a lot of waste heat--which all has to taken out through the AC system (you pay to make the heat, and you pay to move the heat outside).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mikefloridamikeflorida Registered Users Posts: 5
    Re: Electrical fan to power ALT

    Thanks BB you answered it for me.. Till my next brain ???? comes up thanks for the info..

    thanks mike, Miami Florida the hot zone.
  • mikefloridamikeflorida Registered Users Posts: 5
    Re: Electrical fan to power ALT

    One more thing BB the alternator would be their to charge the Bat set .. still not a good thought.

    mike
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Electrical fan to power ALT

    In case anyone was wondering why, a typical automotive alternator will use approximately 1 HP when in 'full charge mode' - rather more than most fan motors produce in total.
  • BB.BB. Super Moderators, Administrators Posts: 32,013 admin
    Re: Electrical fan to power ALT

    Mike,

    In general, you would be lucky to get 50% efficiency from your motor/alternator connection.

    A good quality power supply can get 80% or better in energy conversion...

    Also--if you get a good quality power supply, get the remote battery temperature sensor option--usually a good idea (helps ensure the battery bank is fully charged).

    Iota makes a good set of battery chargers... And Xantrex used to (but it appears that they are having problems getting their new TC2 line out to vendors--sad. The original TC line was very nice for use with small generators).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.