Alternator tie in

FarmerFarmer Registered Users Posts: 24
I am grid tied and would like to tie in an alternator from water wheel. Do I bring it to the 8kw sunny boy or can I tie it into my combiner box. Or can I do it at all?


  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    It depends on what the output of the alternator is. If you are using DC from an internal rectifier bridge, and the voltage is high enough to be within the MPPT operating range of a separate MPPT input of the SB, then you could probably use that for grid tie.
    Unfortunately the operating characteristics curves (current versus voltage versus flow rate) of a water turbine are not particularly well suited to a normal MPPT CC or GTI which has been optimized for PV input.
    You could use one of the Midnite Solar classics along with a Midnite Solar Clipper to get very customizable performance to charge a battery bank. But nothing like that comes to mind for GTI.
    Bottom line is that I have never seen anyone using a small water turbine to feed a grid tie inverter, so you have entered poorly charted waters.
    SMA SB 3000, old BP panels.
  • FarmerFarmer Registered Users Posts: 24
    So than a wind machine turns the alternator the same as a water wheel but the water is more constant. Can you tie in wind then? and still looking for the right alternator like DC-540 or another permanent magnet. I would like to stay away from batteries for now using the grid to bank extra power generated.
  • BB.BB. Super Moderators, Administrators Posts: 29,994 admin
    You would need to find an alternator that matches the blades/tower characteristics, and you would purchase a GT inverter designed for use with a wind turbine. The GT inverter would take the variable voltage/current/frequency of the alternator, turn it into DC power (typically with an external or internal rectifier), then reconvert that DC back into AC power that is compatible with the AC mains (voltage/frequency).

    Also, typically the GT inverter would be responsible for shutting down the turbine if the AC mains fails (GT inverters can only deliver power if the AC mains are working correctly--The GT inverter shuts down if the AC mains fails for safety, and will shut down the wind turbine to prevent it from over-speeding--Horizontal axis wind turbines, HAWT, will over speed if they are unloaded in windy conditions and self destruct).

    We do not usually get into the details of designing/building wind turbines--There are other websites that have more information:

    Wind Power Links (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    Scoraig Wind "Recipe Book" for DYI Turbines (from Chris Olson... From his 4/11/2013 post) (added from "russ"--Like here but more wind/less solar)
    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP
    Windmax HY-2000 2kW Wind Turbine

    I am not a fan of small wind--Many of the products are not very well built/designed. And you need a very windy site with a good size tower (typically ~60 feet or taller) to collect a "useful" amount of energy.

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