Your walls pay rent. Distributed urban micro-grids powered by the sun.
Solar panels mounted on retractable yo-yo-style mechanisms extend down building facades during peak sun hours and retract at night. Each building hosts multiple 'seed' units that connect peer-to-peer, creating resilient community micro-grids that sell excess power back to the main grid.
Standing on a city street at sunset watching dozens of sleek solar units smoothly retract up building facades in perfect sync, then opening the app to see your building just earned $47 from power generated while everyone was at work—your walls literally pay rent.