Use second-hand panels, hire a contractor to install them, and another contractor to then install and connect batteries and an inverter. Ignore the possibility

Use second-hand panels, hire a contractor to install them, and another contractor to then install and connect batteries and an inverter. Ignore the possibility to sell energy back to the grid, charge your batteries instead. Now, you would have built not a cutting-edge system, but a relatively inexpensive one, with a minimum of red tape and financing shenanigans. (Edited: typos.)