Yes, just make sure you set it to not sell the water and power collected (when the bills come due). It will take a few sim days for your supplies to build up, faster if it is raining for the water.
Something I would recommend when playing off the grid is to pay attention to things that drain off your power, the lights. Try to have all your lighting like candles or lanterns that can be used off-grid. Also, make sure any lights you do have that require power to have those set up to where they automatically turn off if no one is in the room. When my sim was first getting things set up, to help reserve the power I would even have most of the lights completely turned off.
