Other Power Inverter Considerations

Also consider that just because you have 100 amp service doesn't mean you need 100 amp service.  With a Low-frequency inverter, you may be able to get by with 50 amp service and the surge rating would cover momentary surges (typically under 20 seconds) that may come along. Basically, if you have 100 amp service now, and you never trip the main breaker, you can get by with less than 100 amp service.  The question is, how much lower can you go?

Right now, a low-frequency inverter capable of 220 VAC, 125 amp (30 KW) service runs around $11,000 - $15,000.  You can get a 220 VAC 50 amp (11 KW) low-frequency inverter for around $4000.

It may be worthwhile to get a power monitoring device to see just how much current you draw at peak.  The savings in the inverter alone can run in the thousands of dollars.

Another strategy is to  use a smaller low-frequency inverter to power a load center specifically for inductive loads.  This will come with an additional cost for the load center, the feed line and some electrical runs.  This cost can be minimized if you place the new load center near the old load center.

You would then run inductive loads like the refrigerator, freezer, HVAC, well pumps and other things that have motors in them.  The other load center would power lights, TVs, computers etc.  Fortunately, inductive load should be on their own circuits, so there is not any wasted cable runs created by doing it this way.

Power inverter efficiency is typically in the 90 percentile range with 95% efficient inverters commonly available.