Solar energy is an alternative-power standby, and it comes in a couple of forms: thermal and photovoltaic. While both types are relatively promising, photovoltaic is, at the moment, the less expensive option, and it has already been widely proven on the small scale.
Solar photovoltaics are the technology behind what we call "solar panels," and lots of homes and businesses have them on their roofs. These panels convert photons in sunlight directly into electricity. The inability to (easily) store this electricity is currently an issue, and it's not the most efficient form of power generation out there. Still, the technology has a lot going for it: It fits easily into small-scale, home and business applications; it produces no harmful emissions and uses entirely renewable fuel; and it's getting cheaper every year as more manufacturers get in on the action.
Solar photovoltaics are being implemented in larger-scale applications, popping up in huge arrays in the sunniest parts of the country. Both large- and small-scale systems are already connected to the grid, offering an appealingly decentralized system for generating power. Solar-energy production is really only worthwhile in the sunniest areas, but its well-proven ability to supply entire sunny communities with clean power makes it a promising alternative to fossil fuels.
Next, the energy in the stink (and elsewhere) …