In a previous post I promised to write about Battery Back Up. I will do so now. In future monthly postings, I will choose topics and do some research to bring in interesting ideas. In these initial posting I am using my mental database as my only resource as I am trying to “prime” the blog.
You should look at other ways to obtain emergency power. Many homeowners choose gas generators as the right size gas generator can run the entire house. Running your whole house as usual on batteries is an enormous task because batteries drain quickly when large loads are connected to them. When we design a system, we must ask numerous questions of the homeowner. We must find out what are the essential loads to be backed up. Our electrician must install a pony panel and to run the necessary wires so that when the grid goes down, power from the storage battery flows only to the selected loads.
Select Loads to be backed up
Typically, homeowners choose furnace motor, fridge, some lights, an outlet for plugging in a computer and any essential medical appliances.
How Many Hours must battery last?
Decide how many hours the selected loads must be powered. With that information and loads, we can estimate how many kWh of storage to provide.
Sun shining on the panels will add to autonomy once the batteries are charged but in our climate most outages occur during the winter when sun hours are few or panels covered with snow and ice.
None of this is cheap – adding a pony panel and batteries can double the cost of a net metered system.