Grid Tie Inverters

Need help !!!! has anyone had experience with the grid tie inverters ? I am looking at the small turbine type ( plug and play)

So far I have searched out a few but I am having difficulty understanding the specs, especially when it comes to DC in. You can find the same product but each seller might offer a different set of specs on incoming DC. I will paste below a set of specs on one item . note the DC - IN Volts . I will also paste specs from the same page in brackets below this.

The Kit includes the following components...

* A 250 watt grid tie inverter
* A Diode box
* A Dump load box
* An AP box to stack more inverters( up to 3 additional inverters)

STARTER-KIT CAN BE EXTENDED WITH MAX. 3 EXTENSION UNITS
UWT-I-250 EXTENTION-KITS UP TO 1 KW.
DC-IN: 0-55V, AC-OUT: 120/230V 60/50HZ.

WIND TURBINES MODELS (with Peak Watts) THAT CAN BE
CONNECTED ARE 200W-300W-500W-750W AND 1 KW.

So what is it 20V - 54V or 0 - 55 V ?


When I write and ask the seller questions I am either getting no response or answers I know are completely from outer space. I realized there are persons who sell but don't really know a great deal about the product. ( they are not using what they sell)

So without going on and on, with all my questions, I am hoping someone out there can join in and enlighten some of us.

Oh yes and when the say you can turn your meter backwards and sell back to the utility company, that is a whole other story !!

 

plans for building a power inverter

Is this feasable and or can it be done ? like a 3000 watt. Anybody know where to get info on doing it ? thanks Steve

 

7 months later and a little smarter ! 1st grid tie inverter to tell about was a 1200 watt grid tie ( from China ) Description states not to exceed beyond a 600 watt turbine to feed. I used my Windy Nation 500 watt and melted the inverter in 6 minutes with a 10 mile per wind. The input is DC 28V to 55V. These units do not come equipped with a Volt control so be aware when the adds also state they have overload protection. "This does not mean a restriction of 55 V " !!!
The customer support is great, they had me send it back and they replaced it immediately. Now a word of caution on returning international purchased items out of N. America. The return postage cost is unbelievable.
Due to this unit not having a V control they and Windy suggested to me that I might try using a battery bank to feed my controller. Anything over the bank would be to the grid tie. I have an access to many 6 V deep cell lift truck batteries so I built a 48 V battery bank and it is up and running. ( so far )
My question right now to everyone would be : Due to the DC input to the inverter being 28 V to 55 V I chose to use make use of the higher range of V. that might be available during stronger winds. But my 48 V bank will continually be drained to the 28 V lower intake of the inverter before it shuts down. Will I be putting too much of a strain on my 48 V bank requiring it to drop so low, especially in a low or no wind day ? Or would a better alternative be to set up a 36 V bank and only require my batteries to drop to 28 V. I am torn between losing out on the higher volts or possibly ruining my batteries.

 

just a short add on to my last post. The whole reason I chose to use the grid tie in the first place was to get away from using a wet cell battery bank that would produce gas on charging or lose power in or winter months which range in the -10 C to -45 C. So my latest try using the 48 V wet cell bank will be a short trail until I can figure out how to make use of this inverter. Or have a melting ceremony and melt the sucker again to say goodbye to it !

 

have rather quickly answered my own question on a 48 V bank Vs a 36 V bank.
After hooking up to the 48 V the inverter quickly drew all available energy from the bank down to its input DC current at 28 V. (actually
it draws down to approx. 26 V)
It then continues to draw from the bank as soon as a trickle of power enters the bank over this amount. There was a good wind of 10 mile per and makes no difference. To experiment I also rerouted another turbine to the bank but the inverter still drew all energy as it entered the bank.
So a 48 V bank will never recover to its full potential .
I then wired up a 36 V bank and exactly the same results as above. Only difference was I was now only straining my batteries from their 36 V max down to a constant 26 - 27 V being taken by the inverter.
A company in Holland has indicated they sell a Voltage in control that can be set at any Volt required. I will pursue info on that and then let everyone know the results.

 

While I am waiting for the volt control units from Holland for the inverter from China I will tell you about the other inverter system that is up and running. It is an SWEA wind inverter system from Holland. It does come with Voltage control. You let them know what will be feeding your inverter and they will tune the components to match your maximum watt potential. The unit I have is capable of handling 1000 watt. When I first started with this set up I was using their 500 watt set up. I used my Windy 500 and melted it in the first night of decent wind. This is the 2nd time my Wind 500 has melted inverters.
Again the customer support is fantastic from SWEA. They have been quite surprised at the potential Watt out put of Windy Turbines, which translates into good purchases for us who have Windy products. The down side of the SWEA set up is that part of their V control and safety requires electronics that will brake the turbine to control V and blade turn over. To have this happen the normal # 12 wire we are able to use with an AC turbine no longer is adequate. They suggest that at a minimum my wire had to be # 8 to withstand the heat build up in the wire during braking. They are also not familiar with turbine set ups like ours in N. America. They have stated that in Holland a person would set up on a roof top and the maximum wire length required maybe 10 - 15 meters. They were very surprised to learn that my shortest tower was over 10 meters and then I had to feed from the tower to my house. # 8 wire is not cheap and due to using a AC 3 phase this requires 3 strands, so again another added expense . ( I lucked out and found a Home Depot that was clearing all old stock of # 8 for $ 1.15 per meter. The new price was going to be $ 6.78 per meter.
The turbine I have feeding this inverter set up is a Windy 750 Watt with a 35 in five blade hub . ( I believe this is a proto type I am testing as it is not advertised for sale as yet, that I know of )
I am still monitoring how the turbine is working, how the blades grab wind, how quite it runs etc. It is a very big alternator, much heavier than the 500. You can mount it the same way as the 500 . So far the SWEA inverter set up has been the best choice due to offering Voltage control and not having to use a battery bank to feed into it. There are other more expensive inverter units out there that can accept a high Volt input, but my understanding is that they must run with a battery bank. All the more affordable grid tie inverters for sale I believe are an accident waiting to happen if you are thinking of hooking up to wind power. If you use solar then the Volt in are set and no worries of over voltage.
Will get back to everyone on the inverter from China when my Volt control components arrive.
[attachment=1:2b7mhic2]750 side.JPG[/attachment:2b7mhic2]
[attachment=1:2b7mhic2]750 side.JPG[/attachment:2b7mhic2]

 

still waiting for parts and repaired units. Being held up by the Volcano in Iceland and no fly zones.
Will continue update as soon as everything arrives.

 

UPDATE on the 1200 watt grid tie inverter. Parts have arrived from Holland. Last posting I was powering this inverter from a battery bank. Started with a 48 V and down sized to a 36 V bank. The inverter kept this drained to approx 24 V. It advertised cut in was 28 V up to 55 V.
The parts I purchased from Holland (SWEA) were called an AP Box and a Dumpload. The AP box is programed to limit incoming V ( at 55 V ) and then the dumpload cuts in and brakes the turbine. This is the same set up I have for the complete Grid Tie I have from SWEA.
If you read any of the earlier postings you will remember I mentioned they recommended a minimum of a # 8 wire to handle the brake load heat.
NEW INFO ON TURBINE BRAKING. for me anyways. I always thought that you could only brake an AC turbine that was running on 3 wire AC.. Now they have taught me that you can also brake a DC turbine with brushes. This is basically how their dumpload works by shorting one of the wires, so in this case shorting the two DC wires and braking the turbine. I just had to test this out before I wired everything up and sure enough my DC Leeson came to a halt.
Everything is wired up now and running smoothly. I already know to produce good hydro I will have to upgrade my turbine. The Leeson has been great for charging a 12 V batter bank but I will need a little more power now. I do have a Presto 80 and Windblue that I retired so will probably bring them out to test on this unit.
This grid tie also has a AC power outlet but the cord they provide will start to melt with overheat with anything that draws start up power. I changed the cord ( just lucky due to having an extra cord from Holland from another unit) The ends are not just a normal plug-in on the male end.
Although the grid tie is running smoothly I will wait to see how it works in a 20 mile plus wind. Last time I used this grid tie unit I used a Windy 500 and melted the inverter it in about 5 minutes so possibly the only real way to test it now would be to again mount another Windy 500 and step back and watch. So Windy, send me a 500 and i will let everyone know what happens. lol.
My thoughts on this particular grid tie inverter. I think the advertising is misleading, there is no built in V control, it cannot handle the recommended turbine to power it, the internal load is so low any turbine capable of producing some decent power will do harm to it, the recommendation of feeding it by a battery bank is usually what you are trying to get away from. So to do again... NO I would not purchase this unit or any like it that do not include incoming V power control! "
[attachment=1:1gbf54pl]AP box.dumpload.JPG[/attachment:1gbf54pl]
[attachment=1:1gbf54pl]AP box.dumpload.JPG[/attachment:1gbf54pl]

 

In all fairness to this grid tie inverter, due to being a wind / solar inverter it may work very well for a solar panel that has a set amount of Watts / Volts it can produce.
Might just be one of my next projects to work on.

 

CHANGES to the Grid Tie 1200 Watt.
I have removed the Leeson DC 180V turbine and replaced it with the AC Presto 80 that I had retired earlier. In an earlier post I had shared with you that the Co. that supplies the V control and dump loads for the grid tie suggested that the lightest wire I should be using to carry the heat build up during braking would be a # 8 wire.
Having used the Leeson DC 180 there was already a heavy # 4 wire in place to cover the required distance for the DC. , but now that I changed over to the AC Presto this also required a wiring change from 2 to 3 wires.
I had removed the # 4 wire due to lack of wire space to add a 3rd wire.
I had an abundant of # 12 / 3 wire available so I used double lengths and braided the corresponding wires at each end. I know this would still be a shade under adding up to a # 8 but would be close.
Everything is up and running, tested the braking and it is fine. It was making the required 28 V hydro for the inverter to kick in at a light wind so looking forward to see how much it produces when the wind picks up.
If I keep this inverter I will eventually replace it with a Windy 500 or use it for solar panel use

 

Any new wisdom on grid tie inverters? Has anyone found a great inverter that works well with the WindyNation PMA?

 

Hey Beachbum, I don't know about wisdom but after many errors the best one I have come up with so far is called SWEA, from Holland.
Great customer care and this unit can be tuned to meet the needs of wind or solar and also to the energy output of your turbine. If you are just a little computer savy you can get a CD with your units that will allow you to tune your own if in the future you wish to change their use to another turbine or add on / or change them over to solar.
For wind you would have to purchase what they call a start- up unit. This is common for any wind set up from them. If you look back at the set up I am using for the 1200 Watt inverter ( that is part of it )

 

Murray,
I really appreaciate all your replies to my dumb questions. I can tell you've really gone a long way with this, and I respect what information you offer. That said, what did you end up paying for the "start up unit", and what should I order exactly to go with my WindyNation PMA? If you have a link that you can share, that would be great.
On a different note, what was your impression of the Windy 750? Were you able to us you same frame? How did it compare to the 500? Have you heard about the price and release date yet?
Thanks, BeachBum

 

Good morning BeachBum
1st, I really liked the view from your 3rd floor balcony.

Your questions on the grid tie; the following will be the Co. the contact person ( owner ) & link.
Swea Europe BV
Geerke 6
5235 HH
‘s-Hertogenbosch
0031-(0)73-644 5554

Marcel van der Heijden

http://www.swea.nl/

I purchased my start up kit from off of Ebay more than a year ago for approx 300.00. ( kit includes AP box, diode box, dumpload and one 250 watt inverter tuned to your needs. This does not reflect real prices. When I purchase off Ebay I tend to do my bidding if the item is finishing during hours when others may not be available or on holidays and such. I never place bids which drive the price up, I always wait till the last 15 sec and place my bid on a price I was willing to pay and not to go over that.
I have found the best price to be direct with SWEA on everything and that also gives me good customer support on questions and repair / replacement of items if needed.
If you are using a Windy 500 you can give Marcel your power curve and he will tune your inverters to meet the required V per unit.
If you plan on feeding into a grid tie you would require the start up kit plus one more 250 W inverter from them at a minimum.

Other inverters I checked on or purchased did not have a V control. When I enquired how to control the V many of them did not understand English enough to have a conversation, others told me it all depends on the charge controller I use to control the V in.
Some inverters will tell you the cut in and maximum V of their inverters. Some are listed at DC in 12 V to 28 V and advertise you will have 250 Watt ( from 28 V ???), some like my 1200 Watt inverter has a DC in at 28 V - 55V. If you do the math (which I did not ) you are led to believe you are going to receive 1200 watt from 55 V... hmmmm

Your question on the Windy 500 compared to the 750... I really like both. There is no doubt that the 500 has real time power especially when I have melted two different grid tie inverters with it. Even SWEA have told me they were very impressed with the power output of the Windy.
As for the 750, it is a prototype I am using.. If I were to purchase again it would be my 1st choice. Reasons are the mounting system is the same. It is a larger size turbine so I just enlarged the mount to fit. It can sit on the same size pole as the 500. ( This is a 32 ft pole, I have suggested to Windy that I will be raising my towers and I would recommend persons to use a 3 in pipe to accommodate tower height changes) I have the older style Windy 500 so with the new outer housing on the 500 they might be comparable in size but in weight the 750 is considerably heavier.
My reasoning was if both turbines took up the same space, material, pole why not receive more energy for my time invested. I cannot give you a real time cost of the 750 due to Windy using that as a test but I am highly recommending it.
I have a 5 blade on the 750 at the moment. It is not as quiet as the 500 that stands beside it with a 3 blade. In the next week I will be changing the 500 over to a 5 blade as well to monitor the blade noise. At the moment I would not recommend the 750 with the 5 blade in an urban setting due to the sound when it catches wind. I may end up putting a 3 blade in it to see if it runs quieter.
To keep in mind the 750 feeds a grid tie which allows it to spin up to the max 55 V in before any breaking occurs. The 500 feeds a 12 V, 1030 W hr. battery bank so the load is much different and maybe limiting the spin on the 500. ( that is why I am also testing the 5 blade on the 500 )
Windy just finished purchaseing a new lot of 500 W turbines from their manufacturer and informed me that they would not be able to order more 750's for some time. ( the 750 is my choice and I can still use Windy blades on it )
Well Beachbum this is the end of this short novel. For your pole set up and mount system, I really like the work Tom is doing.

 

Murray,
Thank you for taking the time to write your "novel". The information is very informative, and I plan to call them and price their 1kw grid tie inverter in IP-54 case (so I can add other junk to it later). Do you happen to know if their equipment is UL approved? It's an issue with Florida Power & Light for grid tie systems in my area.
On a totally separate note, I was reading some of your old posts from last month and I noticed you were having an issue with the SWEA inverter draining your battery banks too low. It sounded like you were able to solve the problem with voltage controls. Of course, I don't have any knowledge compared to you "old pros" but I was courious about something. What is a person were to make 2 battery banks. When one was charging the other was dumping to the grid. Could a controler switch be rigged to sense when a bank is full, divert the charge to the empty bank, while the inverter begin dumping the full bank to the grid. You won't have to limit you PMA, and you would get a full charge and discharge each cycle. Seems like you could gain the lost (or never realized) power from braking control.
You guys are the experts. Does this type of switch controller already exist? Is this a concept already in use or just not practical. Please enlighten me.
BeachBum

 

The SWEA units are being tested to be accepted for UL and CSA. Marcel knows it is an important issue to have completed. He will be able to give you an update when you contact him. I am also going to give you his email. He has been working out of his home computer for the last week as he has just opened up a new warehouse.
Swea - Marcel van der Heijden
marcel@swea.nl

I was using a battery bank on a 1200 Watt inverter ( from China) while I was waiting for SWEA components to control the V and braking.
Your idea on using two battery banks to feed the inverter. What I do know is the inverter will drain the battery bank faster, Much faster than you can fill a bank from your turbine. Your regular grid takes big gulps ! As fast as you can produce it, it is gone.
The reason the inverter is so effective is as soon as you are developing cut in power it will take everything you have upto your High V limit. The braking that takes place to then control the incoming V is only in sec. and then back to receiving power once again.
What I do like is the furling system Tom and others have been developing and if this is also used in conjunction with the V control braking / dumpload for the grid tie it would be a very good match.
Soon I will be testing Windy's new prototype mount and furling system and I will try it out on different systems. Oops, maybe that was to be kept a secret. But very soon they hope to be able to offer their customers a Windy mount with furling.

 

Thanks Murray. I hope some day I can have "favored nation status" like you and get all the new toys before everyone else. I'm jealous! I will email Marcel soon. I really appreaciate all your support and rapid replys.
Regarding the 2 battery banks, I was wondering if you could separate the banks with some type of switch, so that the inverter wouldn't even see the other bank until it was full. Then when it switched to "gulp up" all the power from that full bank the PMA would be charging the first until it was full, and then the inverter would switch to that bank. It's hard to describe this. Do you get it? Does this concept already exist?
BeachBum

 

hey favored nation status eh ! Heck I pay for most of my stuff. The main reason I may have some toys is because I have a lack of patience and I am always asking them " but what if " If it has not been done yet I am eager to try it and give them feedback for others to follow. If I try it in enough different ways and wind conditions and it passes those tests, then it may have a chance to be a new product.
Then others usually do a much better job than what I started !

I think I understand what you are saying about the two battery banks. BUT when I say the inverter will take a big gulp and drain your bank, it happens in light speed. Your PM will be still charging and charging and so on to replenish the other bank. Now why would you want to have to maintain a battery bank that will require a box and vented during charging / do the same over for two banks when you can have a nice clean transfer of power using just the inverter and V control units already available.
I have about 30 lift truck deep cell batteries but I am trying to move away from all of them due to venting & maintenance. Also our winter weather takes a big bite out of our batteries power as we get down to regular weather of - 35 C to - 45 C. I do not want the wet cell banks in my house !
I have a dry cell bank in the house now and all the other towers feed grid tie inverters.

Now what kind of wind do you get from your ocean side location ?

 

Just installed a Taylor Anemometer on the dune yesterday with my daughter. Got it online from Target for $79. Of course summers are more calm, but the wind usually blows at least 10-15 mph all the time. In the winter it is much worse, especially when there is a "Noreaster". I'll let you know, as I collect more data. Today was calm at 16 mph average. Right now it's clam, with clear skies, almost 9PM, and the wind is out of the SW, steady @ 10.1 mph.
BeachBum

 

Murray,
Where in the world do you live with such cold temperatures?
BeachBum