Originally Posted by
fromaron
Are you planning to rewire your house, leaving the power point intended for your off-grid operation in island mode? With separate protection circuit, obviously.
This might be a bit challenging depending on how your house is wired at the moment - suggest speaking with your local sparky.
Your power factor of 0.9 is good meaning 90% of generated power is used to do the real work.
Lets say your highest power demand detected was 479.4 Watts. With 0.9 power factor your system had to generate 532.7 KVA of power.
This is your starting point.
Allow for surges and unexpected disturbances - 10% power reserve you need at least 600 kVA inverter to service your highest power demand.
To decide on a number and size of batteries, look at your so called load profile or how the power demand changes over time. If you have the same load pattern any day of the week then make your load profile chart for over 24 hours (with 1 or 2 hours steps) and then add the kWh generated. I suggest you also research the solar profile in your area to understand how much time your solar panels will feed the system plus charge your batteries and how much time your batteries will feed the inverter.
Batteries capacity is important to consider when making your selection so that they do not completely discharge while running your power point.
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