Generator Powered Grid Tie Inverter - Please.

[LowGear]

I'm in Hawaii and the power just went up to 36 cents a KWH.  Hey, that's still better than 44 cents like last year.  I just don't seem to be able to find an inverter that will meet code and hence the power companies approval for grid tie.  Theories are a beautiful thing but an actual installation or NEC approved inverter would be really nice.  Does anyone know of a successful grid tie hook up that uses a generator or could use a generator's power? 

Casey

[Capt Fred]

Howdy Casey

I'm looking at the sunnyboy as Jens mentioned for my application because it will be easy to bridge rectify the A/C output to D/C - and the sunnyboys accept a wide range of voltage.

If the utility doesn't care about the source (i.e. wind solar or generator - really it shouldn't matter what the "D/C" voltage source is - then you're golden.

If they do then get an Outback or Xantrex grid-tie with a battery bank - these units have battery chargers and are really reliable (my outback is 5 or 6 years old)  A friend has been grid-tied with his outback and running power back to the grid, but it's a bit more complicated.  Take a 48 volt grid-tie inverter and a standard step-up (down) transformer (check the korean stores - koreans love their electronics and everything in korea is 220 volt)  take 110 volts which will STEP DOWN to 55 volts - just about perfect input for a 48 volt grid-tie inverter - take that 48 volts A/C and bridge rectify to D/C and bob's yur uncle - you'll be putting power back into the grid.  FWIW the korean step up transformers are rather light duty you will really need to wind your own for long term use - really only good for testing purposes but they work.  I  know this works, a friend out here has been doing this for over a year with great success (after upgrading the step-down transformers)

Another way would be to bridge rectify to D/C and then run thru an Outback MX60 but this is a rather expensive option.

Hope this helps

Cheers, Fred

[mike90045]

Another way would be to bridge rectify to D/C and then run thru an Outback MX60 but this is a rather expensive option.

And un-tested.   The MX / FX have a hard DC input limit around 150V, then a firmware flag gets set, to void the warranty.  If you have ANY spikes or excursions, your warranty is toast. 

And it's MPPT may not even track the wobbling DC out of the rectifier.  It's trying to curve match to a solar PV panel, and who knows what ripple loaded DC will do to it.     Some big honking filter caps might help clean it up a bit, but driving a 60V multiphase alternator (like a big truck alternator) will give a cleaner DC that may have more success.

[LowGear]

Thanks for your thoughts. 

Does anyone know of a successful grid tie hook up that uses a generator or could use a generator's power?

I'll be chatting with a licensed engineer in the next few weeks and I'll ask about getting him/her to certify a rectified generator.  I've even been looking at three phase generators for cleaner rectified DC.  And then there's always finding a wind turbine system and driving it with the generator rather than hot air (you know as the climate heats up the efficiency of wind will be negatively affected as well ).  I've heard of people that once they have the bidirectional meter installed just going with the over spun induction motor out in the secret room.  But I'd really like to hear about legal working systems.

Casey