Driveways, Walks, Pathways: Developed countries like the United States devote an enormous amount of space to highways, parking lots, and sideroads/driveways. Covering the ground with non-permeable pavement and asphalt causes rainwater runoff issues that cities and municipalities must deal with. The use of permeable pavement helps reduce the amount of runoff, especially when used in conjunction with rain gardens, drainage swales, water retention ponds, berms, and other runoff reduction strategies.
Heated driveways installed in cold climates can require substantial amounts of conventional energy to keep from freezing. This cost can be reduced or eliminated by heating using electricity from a solar electric system or circulating warm fluids heated by a solar thermal system. You can learn about these in the GBDKit.