I am installing a 7kw system with LG mono ACe panels. I would really like to have the option of supplying my own power in the event of a long term power outage. How can I attach a back up system with the panels only producing 240 AC, and get the panels to produce power without the panels sensing the resistance of grid power?
Help with battery back-up on a grid tie AC system
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I am installing a 7kw system with LG mono ACe panels. I would really like to have the option of supplying my own power in the event of a long term power outage. How can I attach a back up system with the panels only producing 240 AC, and get the panels to produce power without the panels sensing the resistance of grid power?
You can look at the Outback Radian series or maybe Schneider or there is also the SMA Sunny Island. -
I am installing a 7kw system with LG mono ACe panels. I would really like to have the option of supplying my own power in the event of a long term power outage. How can I attach a back up system with the panels only producing 240 AC, and get the panels to produce power without the panels sensing the resistance of grid power?Comment
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I am installing a 7kw system with LG mono ACe panels. I would really like to have the option of supplying my own power in the event of a long term power outage. How can I attach a back up system with the panels only producing 240 AC, and get the panels to produce power without the panels sensing the resistance of grid power?
You mention the panels, but do not mention if you've already purchased an inverter?
We have used Outback's Radian to do what you have described. +99% of the time, we are grid-tied and sell/buy via our net metering agreement. When the grid is down, it continues to supply AC power by drawing on the battery bank. So, most of the time, our battery sits at either the 'night' voltage or the 'day' voltage.
inMichiganComment
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Thanks for the replies
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You mention the panels, but do not mention if you've already purchased an inverter?
We have used Outback's Radian to do what you have described. +99% of the time, we are grid-tied and sell/buy via our net metering agreement. When the grid is down, it continues to supply AC power by drawing on the battery bank. So, most of the time, our battery sits at either the 'night' voltage or the 'day' voltage.
inMichiganComment
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Thanks for the replies
Only way to do that is to do an AC coupled system. This requires a separate hybrid 240 volt inverter with a shutdown relay to shut down power from the array when the batteries reach near full charge. Such systems are complex and expensive, but provide the option of independent operation.Comment
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Only way to do that is to do an AC coupled system. This requires a separate hybrid 240 volt inverter with a shutdown relay to shut down power from the array when the batteries reach near full charge. Such systems are complex and expensive, but provide the option of independent operation.
The Radian (or whatever inverter you choose) supplies what you are calling "grid resistance." It effectively creates an isolated grid segment (an intentional island) that provides the voltage and impedance characteristics that the inverters need to operate. The inverters will NOT shut down when the batteries are full; thus you risk frying either batteries or electronics if they continue to produce when the batteries are full. That's why you need the additional relay(s.)Comment
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