Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Grid Tied + Hybrid in one system

  1. #1
    Join Date
    Aug 2018
    Location
    Philippines
    Posts
    16

    Grid Tied + Hybrid in one system

    Hello All,

    As stated above, one client of ours wants a grid-tied system with a hybrid system for resiliency. I don't have yet the rating of the distribution panel that we are about to install. The plan is to do a supply/line side tap for the grid tied system and do a load side tap with the hybrid system. Is there a code reference prohibiting to do grid tied and hybrid in one system? Thanks in advance.

  2. #2
    Join Date
    Dec 2012
    Location
    Placerville, CA, USA
    Posts
    19,765
    There is no code prohibition against having both types of system at one site.
    But a high quality hybrid system will allow you to incorporate as high a grid tied power total as you want. That is why it is called a hybrid system.
    It is true that the ATS component of the hybrid system will limit the amount of power to be sold back to the grid, but I still have the feeling that a single integrated system will be both more cost effective and more efficient than two independent systems.
    This may be either an AC coupled or a DC coupled system. I suspect that an AC coupled system such as the Sunny Boy/Sunny Island system will be better able to accommodate a large amount of grid tied power.

    Sent from my XT1585 using Tapatalk

  3. #3
    Join Date
    Aug 2018
    Location
    Philippines
    Posts
    16
    Quote Originally Posted by GoldDigger View Post
    There is no code prohibition against having both types of system at one site.
    But a high quality hybrid system will allow you to incorporate as high a grid tied power total as you want. That is why it is called a hybrid system.
    It is true that the ATS component of the hybrid system will limit the amount of power to be sold back to the grid, but I still have the feeling that a single integrated system will be both more cost effective and more efficient than two independent systems.
    This may be either an AC coupled or a DC coupled system. I suspect that an AC coupled system such as the Sunny Boy/Sunny Island system will be better able to accommodate a large amount of grid tied power.

    Sent from my XT1585 using Tapatalk
    With that regard, Can I combine the inverter output circuit of let's say (4)grid-tied inverter and the AC output of (1)hybrid inverter and connect it as supply/line side tap? By the way we are using Solax SK-TL5000E hybrid inverter with Emergency Power Supply(EPS) function. Thanks for your input!

  4. #4
    Join Date
    May 2011
    Posts
    4,701
    Quote Originally Posted by HecThor View Post
    With that regard, Can I combine the inverter output circuit of let's say (4)grid-tied inverter and the AC output of (1)hybrid inverter and connect it as supply/line side tap? By the way we are using Solax SK-TL5000E hybrid inverter with Emergency Power Supply(EPS) function. Thanks for your input!
    I don't believe there's any problem with that.

  5. #5
    Join Date
    Nov 2015
    Location
    CA, USA
    Posts
    683
    You have to have some type of ATS to isolate the local system from the grid when in backup mode. You can interconnect the grid-tied inverters to the service supply side and the hybrid inverter to the backup input to an ATS. How you connect the ATS into the system depends on what you want to backup and if you want the ATS to be the service disconnect.

  6. #6
    Join Date
    Oct 2009
    Location
    Austin, TX, USA
    Posts
    10,191
    Quote Originally Posted by pv_n00b View Post
    You have to have some type of ATS to isolate the local system from the grid when in backup mode. You can interconnect the grid-tied inverters to the service supply side and the hybrid inverter to the backup input to an ATS. How you connect the ATS into the system depends on what you want to backup and if you want the ATS to be the service disconnect.
    Don't hybrid inverters usually have their own ATS with separate terminals for connecting to the grid and to the protected loads? And yeah, I know we're not supposed to call them protected loads any more, but you know what I mean.

  7. #7
    Join Date
    Dec 2012
    Location
    Placerville, CA, USA
    Posts
    19,765
    Quote Originally Posted by ggunn View Post
    Don't hybrid inverters usually have their own ATS with separate terminals for connecting to the grid and to the protected loads? And yeah, I know we're not supposed to call them protected loads any more, but you know what I mean.
    Yes, in general they do. That is necessary to both allow grid interaction and provide islanded power when the grid is down. Some have an additional set of AC input terminals for a local generator and may include generator control circuitry.

  8. #8
    Join Date
    May 2011
    Posts
    4,701
    Strictly speaking the switches in these inverters don't typically have a 'transfer' function. They only disconnect the 'island' from the grid to let it operate on its own. The code term is 'micro-grid interconnect device'.

  9. #9
    Join Date
    Oct 2007
    Location
    New Jersey
    Posts
    6,211
    Quote Originally Posted by GoldDigger View Post
    Yes, in general they do. That is necessary to both allow grid interaction and provide islanded power when the grid is down. Some have an additional set of AC input terminals for a local generator and may include generator control circuitry.
    I'm not current on PV technologies except for what I read in the general press and surfing the Web, but If you're in island mode, don't you need batteries or some other storage to smooth the demand/supply response of the system?

  10. #10
    Join Date
    Nov 2015
    Location
    CA, USA
    Posts
    683
    Quote Originally Posted by ggunn View Post
    Don't hybrid inverters usually have their own ATS with separate terminals for connecting to the grid and to the protected loads? And yeah, I know we're not supposed to call them protected loads any more, but you know what I mean.
    You are correct and the hybrid inverter will then have two outputs, one for the utility interconnection and one for the protected load panel. The OP stated they were connecting the hybrid inverter to the service panel with no other connection so it is unclear if the inverter they are using has two outputs and internal switching. If it only has one output intended to back up a load then there needs to be an ATS.

    I must have missed the memo, what's wrong with using "protected loads"? "Critical load is worse and I hear people using that.

Posting Permissions

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