I don't believe there is too much confusion in terms of what alternative energy source work or do not. There are, however, plenty of entities pushing forward their interests.
For a quick run-down on the truly viable alternative sources:
Solar power:
* Works, it's sustainable, it will only get better. It has already reached grid parity in many markets, this trend will absolutely not reverse but continue. * Is nowhere near it's optimal efficiency, has tons of room for optimization of both cost efficiency and conversation efficiency (basically reducing the area required to reach a desired power output). * Requires a grid that is built with solar power in mind. Requires baseload generation, of which nuclear and natural gas are the best candidates (assuming the natural gas glut continues on).
Wind Power:
* Works, proven technology. It has reach grid parity in more markets than solar. * Is nearly at the limits of it's theoretical efficiency. There are pretty much only manufacturing cost and economy-of-scale gains to be had here, which I think really hurts wind power's future unless some sort revolutionary change happens in manufacturing process takes place. * Also needs a grid that plays nice with, with baseload assistance.
Hyro:
* Not much to say here, it's capped, very little room to grow. Extremely economically efficient but serious ecological effects.
Geothermal:
* See hydro, but will less serious ecological effects.
Biomass:
* Total crapfest. Until such time as we can bio-engineer some plant that turns sunlight directly into petrol or the like, biomass offers a a net gain to carbon emissions, especially in the case of corn. Sorghum/Sugar Cane is more interesting but hasn't panned out as of yet, mostly because of it being picky where it grows (it seems unwise to turn rain forest area into sorghum fields in the name of alternative renewable energy).
Nuclear:
* Massive amount of energy in a small form factor. * Potential for very bad accidents. (see: black swan event) * Nuclear proliferation concerns, nuclear waste to manage. * Decent economic efficiency. * Nuclear has a niche but can hardly be the world's power source. Would you want every country to be full of nuclear plants, including those whose governments change monthly, are prone to extreme corruption, etc. There are plenty of trade groups they are lobbying for support of "safe" nuclear technologies such as Thorium based breeder reactors, but the truth is these designs are almost entirely vaporwear, and have faults and dangers of their own.
I feel rather strongly the solar is the way forward, with nuclear in stable well-regulated countries for base load, with natural gas/hydro/wind/geothermal filling in the rest.