Battery backup of PV system ?

Reply

  #1  
Old 11-23-14, 01:05 PM
L
Member
Thread Starter
Join Date: Jul 2007
Location: Mexico
Posts: 364
Received 1 Vote on 1 Post
Battery backup of PV system ?

We have a relatively new (4 months) PV system which is working great. The inverter is a Fronius 3000. We have a bi-directional meter. When we lose power from our power company the inverter shuts off. Is there a simple/inexpensive way where when we lose power from the grid we could power the inverter so that the panels would act as a short term generator ? Thanks.
 
  #2  
Old 11-23-14, 01:17 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,965
Received 6 Votes on 6 Posts
You most likely have the system set up to only sell electricity back to the utility. What battery set up do you have to power the inverter? You can't use that same inverter as it would energize the POCO's lines. You must have a disconnect in place to prevent that.
 
  #3  
Old 11-23-14, 01:30 PM
L
Member
Thread Starter
Join Date: Jul 2007
Location: Mexico
Posts: 364
Received 1 Vote on 1 Post
The way our system works - if we have household demand our panels service that if they can, else we pull from the POCO (your term). If we have no consumption our production goes to them and we get a rolling 12 month credit.

The guy who installed the system is due out in the next week or so - I was just hoping to get a little smarter beforehand. Thanks.
 
  #4  
Old 11-23-14, 01:36 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,965
Received 6 Votes on 6 Posts
How large is your battery system?
 
  #5  
Old 11-23-14, 01:44 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,874
Received 1,342 Votes on 1,240 Posts
Is there a simple/inexpensive way where when we lose power from the grid we could power the inverter so that the panels would act as a short term generator ?
No... I don't believe there is.

The inverter currently in use there needs PoCo power to provide the synch between it and the lines. The inverter must match the PoCo line frequency exactly. You'd need a different inverter and some way to switch it in safely. That would be neither simple or inexpensive.
 
  #6  
Old 11-23-14, 02:01 PM
L
Member
Thread Starter
Join Date: Jul 2007
Location: Mexico
Posts: 364
Received 1 Vote on 1 Post
Thank you both. We have no battery system. What we DO have is a large 'surge protector' box street-side which monitors all the in-coming power. Perhaps I need to change my focus in that area. All I am interested in addressing are those short 2 minute outages.
 
  #7  
Old 11-23-14, 02:08 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 60,874
Received 1,342 Votes on 1,240 Posts
All I am interesting in addressing are those short 2 minute outages.
It would be pretty costly to install a battery bank, inverter and transfer switch for small outages.
 
  #8  
Old 11-23-14, 02:12 PM
L
Member
Thread Starter
Join Date: Jul 2007
Location: Mexico
Posts: 364
Received 1 Vote on 1 Post
Thanks - Hope all is well in NJ - originally from Oradell (exit 165 :-) )
 
  #9  
Old 11-23-14, 03:06 PM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,693
Received 47 Votes on 46 Posts
There are a few options, here is one: Solar Power Wholesale Distributor | AEE Solar

It's got some complexity!

Maybe better is a standby propane generator.
 
  #10  
Old 11-23-14, 03:12 PM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,965
Received 6 Votes on 6 Posts
By the time you got out of your chair and started for the grid lock out or generator, the power would be back on. We're talking two minutes, right?
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: