Picking an inverter

[JMaris]

So, I am starting to look at inverters. Let me start by saying that I am going to be starting with a small turbine, then probably add some solar, then get a bigger/more turbines. I want it to be the whole shebang... Grid tie inverter, battery charger, charge controler. So, is there a product out there that can do everything? If so, should I start with a small one and replace/add to as I up size my system or should I just buy the biggest/best from the get go?

[ChrisOlson]

The two Gold Standards are either the Outback GVFX-series or the Xantrex XW-series.  I have experience with both, and both do everything you mention.  I guess Magnum Energy inverters are good, but I have no personal experience with them.

I think just about everything else is a wannabe.

For any of the above mentioned Big Three expect to drop at least $3-4 Grand on a starter inverter system.  The prices you always see listed are only for the basic inverter.  It doesn't include the accessories that go with it (AC and DC conduit boxes, control panels, gen start modules, etc.).  The Magnum and Xantrex inverters are 120/240 out of the box.  The Outback is 120 volt only but you can stack them for 120/240.  I guess Outback has a ready-to-go 120/240 setup, but I have no experience with it.

You have to know what your loads are so the inverter can run them.  You have to size a battery bank correctly to meet those loads and your available generating capacity.  You have to decide if you want split phase (120/240 volt) or just 120 volt.  Most off-grid installations are 120 volt only with an autotransformer to run singular 240 volt loads like a well pump.  Most grid-tie applications are split phase.  Big off-grid systems are 120/240 split phase.

You mention grid-tie.  Don't waste your time (my humble opinion).  Check into the requirements for a grid-tie system from your utility before you do anything else.  It usually doesn't pay off to grid-tie unless you get a premium for power "sold" to the utility, and/or there is a FIT (Feed In Tariff) program like in Canada.  Grid-based with battery backup to supplement grid power, or completely off-grid is more practical in most cases, since both will power your loads independent of grid power and your lights stay on when the grid goes dead.

Way too many variables to just say "oh yeah - you need this".
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Chris

[Frank S]

Chris what I like about the outback brand is this

   
Designed for either stand-alone or utility-interactive applications, OutBack's new generation of power inverter is rated from 2000 watts to a continuous output of up to 3600 wsatts depending on the model. Each GTFX inverter/charger is a complete power conversion system, comprising a DC to AC inverter, a battery charger and an AC transfer switch. OutBack gives you the flexibility to design your system to meet any specific power requirement. Up to eight GTFXs can be connected (stacked) in a variety of series/parallel configurations for 120 VAC, 240 VAC (split phase) or 120 & 208 VAC (three phase) output for a total of 16,000 watts of AC power! A 50 Hz export version is available for 230 VAC or 230 & 400 VAC (three phase) applications.

[ChrisOlson]

Chris what I like about the outback brand is this

The Xantrex XW units do all the same thing except they have split phase with auto leg balancing built-in as standard, have a higher capacity battery charger for larger banks, have more surge capacity, have gen support (gen and inverter can share heavy loads - Outback doesn't do this), have dual AC inputs (both grid and gen - Outback only has one AC input), are stackable up to 24 kW - and of course the biggie - they cost twice as much.

Xantrex is now owned by Schneider Electric - the same people who build SquareD equipment.

Xantrex builds the GT-series up to 3,310 amp output, 560 kW three-phase for both wind and solar.

Just depends on how big of a unit you really need.  A GT500 will set you back right around $160 Grand.

Little off-grid systems typically use Outback equipment because it's cheaper and good quality.  Big off-grid systems typically tend towards Xantrex because it takes a lot of stacked Outbacks to match one XW.

Amazingly, the same engineers have designed and built all this top-name equipment.  It all started with Trace Engineering.  Trace, later bought by Xantrex (and Schneider now owns Xantrex) built the equipment that everything else in the industry is measured against.  When Trace got bought by Xantrex some of the engineers left there and formed Outback Power Systems.  Those same engineers have now left Outback and formed Midnite Solar - and invented and built the only successful small wind MPPT controller for battery charging applications in existence - the Classic.

I've been told, "Just wait until we (Midnite Solar) build the ultimate off-grid inverter".

So it's not like you're going to go wrong with any of this equipment.  It gets back to what you need and what you got to spend to get started.

Personally, I've gone with all Xantrex equipment with three MidNite Solar Classic controllers.  I've never cared for Outback's proprietary communications protocols when you want to install computerized monitoring and logging systems.  But that's what fits my needs.  Other people have different needs.
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Chris

[boB]

Amazingly, the same engineers have designed and built all this top-name equipment.  It all started with Trace Engineering.  Trace, later bought by Xantrex (and Schneider now owns Xantrex) built the equipment that everything else in the industry is measured against.  When Trace got bought by Xantrex some of the engineers left there and formed Outback Power Systems.  Those same engineers have now left Outback and formed Midnite Solar - and invented and built the only successful small wind MPPT controller for battery charging applications in existence - the Classic.

Chris

In addition, here is a little writeup of the history that was done a couple of years ago...

http://www.hardysolar.com/inverter/inverter-history.html

[ChrisOlson]

boB, thanks for that.  That was a good read (I always enjoy reading Robin's stuff anyway).  I wasn't quite sure how Magnum Energy fit into that whole scenario.  But now I know.  Very cool.
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Chris

[bob g]

while we are doing the history lesson a couple of questions if i may?

1. where did exeltech fit into the picture?

2. where did the ups guys fit into the history of inverters?  topaz was an early unit, as were exide, later apc and others?  were their guys crossing over between these branches of the inverter game?

bob g

[JMaris]

I forgot to mention, I want a grid tie to so I can buy if need be. I don't really care to sell back. I just want to have more electricity available if I need it. THere is a guy that lives in town thatjust setup a skystream3.7 set up in his back yard a month or 2 ago. He is a friend of a friend. My buddy is trying to get me lined up to go see his setup and ask him a bunch of ? about what all the utility company requires. That should make that part alot easier.

Thanks for all the help everyone! Now I just need to decide which one I want to get!

[ChrisOlson]

I guess the main thing you need to ask yourself is why do you want to put in wind and solar power when you can get grid power?  It is more expensive to generate your own electricity than it is to buy it off the grid.  Especially with wind systems because they cost more per kW of installed capacity than solar and it is unlikely that you will even pay for the equipment in savings in your lifetime, much less recoup long term operating costs of a wind system.

If you are off-grid where standby generator power costs 80-90 cents/kWh, then it's a different story and a wind system quickly pays for itself in reduction in generator hours and replacing worn out gensets.

So, basically, if you're expecting to save money, you're on the wrong path completely.  This is more than likely not what the Skystream installer or owner will tell you.  But one is selling a turbine and using bogus numbers to sell it, and the other is getting an expensive education and he don't have his degree yet.

If you want to do this to be independent, or because you believe it's the right thing to do instead of continuing on the path of using fossil fuels for energy, then the sky is limit and cost is no object.  Just be aware that you cannot be independent with a grid-tied system unless you have a battery backup system, or hybrid on-grid/off-grid type setup.

I figured this out one day, and with the money my wife and I have spent to live off-grid and generate 25-30 kWh per day with wind and solar, it would take 34 years to recover our cost in equipment vs what we could just buy the power off the grid for.  And it is likely in that amount of time that every piece of equipment we own will have to be replaced at least once.
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Chris

[JMaris]

Well I don't want to do wind and solar power to save money or the environment necessarily. We want to do it to be more self sufficient. We grew up in arkansas out in the country. Now that we have started our family, we bought 10acres out of town, set a double wide on it, and got after it. We have a garden again, raise chickens, are in the process of getting some goats and will have a few cows in the next year or so. Our whole house is electric. So, it just makes sense to us to try to be self sufficient in that area as well... Or as best as we can.

[bob g]

Jmaris

i think you have your head on straight, and i think your attitude is commendable.

as long as one accepts the premise that he is likely never to get a payoff on his investment in AE, he will never be disappointed.

what he will learn in the process is probably worth far more than he would have paid in the differential,  what is a college education worth these days?  what does it cost?

anything one can learn to do himself, even if it costs more than he can buy it for, is worth doing.... because one day he might not be able to afford such and it might not be available at any price!

far better to know how to make some power via wind, water, sun or some other alternative, than sit miserably in the dark shivering in the cold.

i like you already!
and i really like your wife! any girl that is hip to doing the self sufficiency thing from the git go is a keeper in my opinion.



good luck
bob g

[JMaris]

Haha Thanks bob. She wasn't quite into it from the get go, but neither was I back then. When we moved out here to west texas about 5 years ago alot of things changed though. Mainly the fact that we can afford to have "projects" now! Alot of those little ideas in the back of our heads came to the forefront.

[JMaris]

Well it's me again... We are getting pretty close to pulling the trigger on this project.  I have my motor torn appart, getting ready to machine down the shaft to put some neo mags on it. I have ~150 foot of 6" pipe for my tower and jib. Which brings me back to this topic that I am still undecided on... I really want a xantrex xw4024 but Im not sure if there is that much in the budget right now. The main reason I want the xw is because a good bit of my daily power consumption is 240 (2 water well pumps, ac/heat, dryer). So, do you guys think it would be a better idea to save a while longer and get the xantrex or should I go ahead and get the outback gvfx3524 to get me started and stack on another down the road to get 240vac?

[bob g]

my vote would probably be for the outback unit

xantrex while it used to be very good, has been questionable with all
the changes in ownership, not sure it is on the same level as outback now.

bob g