I am new to solar and am currently running a grid-tie Enphase IQ7 solar system. I live in a region in which the power company will not buy back any overproduction (I am the first to have solar for my utility company, which means the laws and regulations around solar are almost non-existent). I would love to explore a battery backup system that would capture my overproduction and allow me to retain that electricity for later. I would love to use the end phase battery backup system, but can't justify spending $18,000 on a battery backup system. Would it be possible to do my own grid tie battery backup system to capture this overproduction? Any thoughts I appreciated ?