Some Clean Power Trends
Wind Power
A heartening statistic for clean power enthusiasts would be that wind-power has now become the fastest-growing new source of electricity worldwide. The annual growth in wind power based electricity is around 20-30%. At the current rate of growth the industry will be 10 times its current size in a decade. Further the cost of wind power has come down from 40 cents per kilowatt hour to between 4 and 6 cents now. Just a little lower and it will be cheaper than fossil fuel power - at least at current rates. Finally since wind does not cost anything, unlike fossil fuels that have to be pulled out of the ground, the theoretical limit for the cost of wind power is zero.
WorldChanging has a post that points to the declining cost of generating wind power. The idea being discussed here is the growing size of the blades in wind turbines. Obviously there is a limit to this which should be reached eventually. The immediate target though is close enough, "The goal of industry and federal researchers is to create wind farms that produce electricity for about three cents per kilowatt-hour, down from about 4.5 cents today". The next round of improvements could target the shape and design of the blades or maybe the turbines themselves. Maybe the foundations need some work too.
MFCs - beyond biomass
Again via Worldchanging: Microbial fuel cells are looking like the next big thing. They can be used to treat waste water in a much cheaper way than current technologies permit. While they are doing that they can also be made to generate either electricity or hydrogen, depending on the exact process. Also unlike conventional fermentation techniques, microbial fuel cells can use any biodegradable, dissolved, organic matter and not just carbohydrate-based biomass. At least one killer app for this process would be as a replacement for electrolysis to get hydrogen out of water. At current count it is ten times more electricity-effective.