We have a 7kW rooftop solar system, six years old, with two battery banks of flooded lead-acid batteries. We sell back to the grid about 6x what we buy per year, even after we charge our Leaf EV. You can take a spin in the Leaf if you like! We went solar to reduce our carbon footprint, and it's just cool to get free energy from a source that won't run out. And it's cool to drive a vehicle that's mainly powered by the sun.