Results 1 to 16 of 16

Thread: How to connect a 24v solar panel to a 12v grid tie inverter

  1. #1
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Question How to connect a 24v solar panel to a 12v grid tie inverter

    Hi guys, I've got a decision to make and need some help.
    I've got a 12v 100w solar panel connected to a 12v 250w grid tie inverter.
    I also have a 24v 120w solar panel connected through a Xantrex power charge controller and charging a 24v 300 Ah battery bank.
    When the battery bank is full the 120w panel is idle and that power is lost. What I would like to be able to do is create a switch somehow to redirect the power so instead of it going to the battery bank to go to the grid tie inverter. The problem here is as I mentioned above is that the panel is 24v and the GTI is 12v.
    I've done a bit of research and I found this step down converters / inverters from 24v to 12v ( some 3A some 5A ). This is definitely one way to do it but I also have one other idea.
    My 24v battery bank is connected to a regular 24v - 240v Dc - Ac 3000w inverter and from it I've got connected a car cigarette lighter type converter / inverter female which takes 240v Ac and puts out 12V Dc.
    What I'm thinking to do is take the power from the cigarette lighter converter 12v and connect it to the grid tie inverter in parallel with the 12v solar panel as an input.

    Will this work??
    What are your thoughts on this?
    Have you got a similar setup yourself? How did you do it?
    Which of the 2 ways to go for?
    Let me know the way you would do it.
    Thanks in advance, your help is appreciated !
    Cheers!
    Great Forum ! Quick help available here at Austech! DASHONY-Solar



Look Here ->
  • #2
    Senior Member ageno2gen1's Avatar
    Join Date
    Jun 2009
    Location
    Lake Macquarie
    Age
    39
    Posts
    526
    Thanks
    327
    Thanked 129 Times in 87 Posts
    Rep Power
    151
    Reputation
    715

    Default

    can we get more specs on the gti please, it should have a voltage range, 12v to something. Most gti are made for 24v.
    Stop being so stupid.. itís my turn!!

  • #3
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    The GTI voltage range is 10.8v to 30v so it will work if I connect just the 24v panel to it but I'm concerned about connecting in parallel both panels the 12v one and the 24v one.
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #4
    Senior Member ageno2gen1's Avatar
    Join Date
    Jun 2009
    Location
    Lake Macquarie
    Age
    39
    Posts
    526
    Thanks
    327
    Thanked 129 Times in 87 Posts
    Rep Power
    151
    Reputation
    715

    Default

    so here are my thoughts, once your 24v battery bank is full your charge controller should pass excess power to the gti, thats its job. If not get a new one. then just connect the 12v solar panel to the gti directly (both with a diode). you could also get a step down transformer as you said. There are also charge controllers that will take a 24v down to 12v for you but not vise versa.

    Have you got the GTI connected to the dump load on the charge controller?
    Stop being so stupid.. itís my turn!!

  • The Following User Says Thank You to ageno2gen1 For This Useful Post:

    Dashony (31-12-11)

  • #5
    Senior Member ageno2gen1's Avatar
    Join Date
    Jun 2009
    Location
    Lake Macquarie
    Age
    39
    Posts
    526
    Thanks
    327
    Thanked 129 Times in 87 Posts
    Rep Power
    151
    Reputation
    715

    Default

    And this is my setup.

    Stop being so stupid.. itís my turn!!

  • #6
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    Quote Originally Posted by ageno2gen1 View Post
    so here are my thoughts, once your 24v battery bank is full your charge controller should pass excess power to the gti, thats its job. If not get a new one. then just connect the 12v solar panel to the gti directly (both with a diode). you could also get a step down transformer as you said. There are also charge controllers that will take a 24v down to 12v for you but not vise versa.

    Have you got the GTI connected to the dump load on the charge controller?
    Ok, I just found this option now for my charge controller. Is called Diversion Control Mode. Until now I thought it only had the power charge and load control options but I found this third option now so when the batteries are full it diverts the extra power to a load. Here you're saying to use the GTI as a load . I'm just wondering what happens if there is full sun , my street loses power that means the GTI will shut off, if the battery bank is full and the GTI is off there is no load than the batteries will overcharge then.
    What do you think?
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #7
    Senior Member ageno2gen1's Avatar
    Join Date
    Jun 2009
    Location
    Lake Macquarie
    Age
    39
    Posts
    526
    Thanks
    327
    Thanked 129 Times in 87 Posts
    Rep Power
    151
    Reputation
    715

    Default

    Yep, i got a switch witch my neighbours and family know that if there is a blackout either shut it down or use some power. The ideal way which i will be doing soon is to have another charge controller but set to a higher voltage running to an "always on load"(typically a large resistor),once there is a blackout the battery climbs but only to what you have set the second controller to.
    Stop being so stupid.. itís my turn!!

  • #8
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    That sounds right, I was thinking to some kind of automated switch to detect when the GTI is off and then export to other load. That would be ideal too. So the system becomes like this: if batteries are full extort to GTI and if the GTI is off extort to this other load.
    I would like that.
    Here are some videos of my system setup is here
    Last edited by Dashony; 01-01-12 at 02:04 PM.
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #9
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    Ok, I purchased a Step down 24v to 12v dc-dc 10A, I've connected my 24v panel to it as input and it puts out the correct 12.4v but if I then connect it to my grid tie inverter, nothing gets sent to the grid.
    Anyone else has this issue? Is there a work around?
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #10
    Senior Member
    Learjet's Avatar
    Join Date
    Jan 2008
    Location
    Queensland
    Age
    56
    Posts
    1,399
    Thanks
    604
    Thanked 1,041 Times in 348 Posts
    Rep Power
    438
    Reputation
    12705

    Default

    I don't own a GTI so I'm just going by what I've read, and that is some "12V" GTI's need >14V to feed into the grid. I've read that a single 12V battery doesn't have enough voltage but two in series does. "12V" panels have a MPP of 18V, greater than the 14V needed to make the GTI start working.

    If the above is correct, then you would be best stepping down to 18V rather than 12V.

  • #11
    Senior Member
    Join Date
    Feb 2008
    Posts
    831
    Thanks
    174
    Thanked 434 Times in 193 Posts
    Rep Power
    208
    Reputation
    2277

    Default

    Quote Originally Posted by Dashony View Post
    Hi guys, I've got a decision to make and need some help.
    Don't you mean you want to spam your website ? if it can be called that!, is it possible that you can put any more advertising on there ?

    Quote Originally Posted by Dashony View Post
    I've got a 12v 100w solar panel connected to a 12v 250w grid tie inverter.
    Cool then you probably wont have any problem showing us the Australian compliance and certification of that inverter ?
    What an absolute piece of junk , a 250W inverter with only a 100W panel on it and it's over heating , there are way more predictable ways to burn your house down

    Quote Originally Posted by Dashony View Post
    Will this work??
    Aren't you the expert , you even have you own forum right ?

    Quote Originally Posted by Dashony View Post
    What are your thoughts on this?
    I thought I had seen it all when Austech's former friend Crash posted video's of his Scientific analysis of a Rose , but really your video describing what a fan is for in only 10 minutes is true work of art , ( as is the superb engineering of the fan mounting effort ) !
    Can't wait to see the sequel .

    Quote Originally Posted by Dashony View Post
    Have you got a similar setup yourself? How did you do it?
    You are joking right ? , actually just doing some sums , with a 100W panel , it should be exporting a massive 400Wh per day into the grid ( in perfect weather ) , That could net you almost a tidy 50 cents a week , surprised more people haven't put their families and their houses safety on the line.

    Just one more thing as if it's not already dangerous enough what is with all those weird arse US plugs , power boards etc ?

  • The Following User Says Thank You to Joey For This Useful Post:

    cwispy (29-02-12)

  • #12
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    Quote Originally Posted by Learjet View Post
    I don't own a GTI so I'm just going by what I've read, and that is some "12V" GTI's need >14V to feed into the grid. I've read that a single 12V battery doesn't have enough voltage but two in series does. "12V" panels have a MPP of 18V, greater than the 14V needed to make the GTI start working.

    If the above is correct, then you would be best stepping down to 18V rather than 12V.
    It sounds right, I think it does need more then 12v to run it as 1 x 12v solar panel puts out about 19v. But 1 x 12v battery is enough to run the GTI. Thanks
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #13
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    I work in IT and the best guys out there in the industry are searching on google when they can't figure out how to solve a problem / issue.
    If I have my own forum doesn't mean I know "EVERYTHING". That is the point of a having a forum to exchange info to give / receive advices/help. A forum is about people in need of certain information coming and helping each other.
    If you know EVERYTHING don't even waste your time just put your phone number down and close this forum.
    I thought by being a "senior member" you have a little more understanding of how a forum functions and that even people with knowledge in the area can come and ask questions. I thought this makes a forum a good forum.

    That, at the bottom that you mentioned is not a " weird arse US plugs " as you call it. It is an international power board so you can plug any devices into it regardless to what type/shape of plug it has.

    I'm not here to spam. I came here to honestly receive some help if any available and I found a few knowledgeble people here which helped me and I thanked them all for their input.
    Did you just have a bad day?
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #14
    Senior Member cwispy's Avatar
    Join Date
    Jan 2008
    Location
    In bed sleeping
    Posts
    1,090
    Thanks
    140
    Thanked 296 Times in 114 Posts
    Rep Power
    205
    Reputation
    1581

    Default

    Holy crap, your website has more adverts on it than google! How many times have you called the fire brigade out to your place to put out the electrical fires caused by your dodgy and from the looks of it, probably illegal setup? I can hardly believe you have gone to so much complexity for what should be a simple system. Where do you live? I want to subscribe to your local newspaper so that I can see the pictures and read the article when your house burns down.
    What would you do if your server was stolen or failed beyond repair?
    http://www.2000cn.com.au/shadowprotect.html

  • #15
    Junior Member
    Join Date
    Dec 2011
    Location
    Victoria, Australia
    Posts
    23
    Thanks
    5
    Thanked 0 Times in 0 Posts
    Rep Power
    90
    Reputation
    10

    Default

    Quote Originally Posted by cwispy View Post
    Holy crap, your website has more adverts on it than google! How many times have you called the fire brigade out to your place to put out the electrical fires caused by your dodgy and from the looks of it, probably illegal setup? I can hardly believe you have gone to so much complexity for what should be a simple system. Where do you live? I want to subscribe to your local newspaper so that I can see the pictures and read the article when your house burns down.
    If you have nothing to add to improve this thread my suggestion is to keep your personal opinion about website ads and so on just for yourself. That will be great. You're just turning this forum into a bitching forum, which I found very helpful until now.
    Great Forum ! Quick help available here at Austech! DASHONY-Solar

  • #16
    Junior Member
    Join Date
    Jan 2010
    Posts
    154
    Thanks
    18
    Thanked 32 Times in 25 Posts
    Rep Power
    122
    Reputation
    152

    Default

    Quote Originally Posted by Dashony View Post
    If you have nothing to add to improve this thread my suggestion is to keep your personal opinion about website ads and so on just for yourself. That will be great. You're just turning this forum into a bitching forum, which I found very helpful until now.
    Now you know what type of people you are dealing with, some are very opinionated....which is unfortunate.
    Last edited by officemanager; 04-03-12 at 12:36 AM.

  • Tags for this Thread

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •