I have two powerwall batteries installed and they have been seamless for the power outages we have experienced. This last storm they provided electricity for the entire house for the duration of the outage. (Fifteen hours). They ran the outdoor hot tub, two refrigerators, a freezer, the heat and lights and media. At $15 per month for each battery over the ten year lifespan it will be several thousand dollars less than installing a generator. Also there is no maintenance on the batteries. So far very happy with them.