Battery backup of PV system ?

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  #1  
Old 11-23-14, 12:05 PM
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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.
 
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Old 11-23-14, 12:17 PM
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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.
 
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Old 11-23-14, 12:30 PM
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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.
 
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Old 11-23-14, 12:36 PM
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How large is your battery system?
 
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Old 11-23-14, 12:44 PM
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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.
 
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Old 11-23-14, 01:01 PM
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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.
 
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Old 11-23-14, 01:08 PM
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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.
 
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Old 11-23-14, 01:12 PM
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Thanks - Hope all is well in NJ - originally from Oradell (exit 165 :-) )
 
  #9  
Old 11-23-14, 02:06 PM
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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.
 
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Old 11-23-14, 02:12 PM
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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?
 
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