I am leaning toward the answer, its not going to work. I think the converter uses the incoming power source to measure and match the voltage and frequency of your supply power. This converter needs to be connected to the grid to work. The power consumption in your house is vairable and the converter dumps all the extra power into the grid. If it is not grid tied, where will the extra power be dumped? I am guessing that operating the unit "untied" would cause problems.