There are no technical reasons not to do what you suggest, but the cost of the batteries, etc to provide the off grid capability will be high.
You may want to simplify the switching and configuration requirements by going to a hybrid system which combines the off-grid capability with grid tied operation when POCO is up.
You may want to simplify the switching and configuration requirements by going to a hybrid system which combines the off-grid capability with grid tied operation when POCO is up.
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