Can I Use The System For Supplemental Power?

Of course.  There are several ways to use the free extra power that your power plant provides.  First might be simply to plug in some appliances, tools, or other items that you routinely use.  Next might be to isolate specific circuits in your home or business and wire them so that you can transfer them to your PowerGenX when it is producing excess power.  You might need an electrician or technician in order to do this safely.  Another way could be to install a plug-in grid tie inverter which automatically runs the excess to your loads or into the power grid.  You can find these inverters online at minimal expense, but some are not UL approved and should be researched before you  try them.