Build Smarter, Not Bigger
I'm impressed by this bit of clever engineering efficiency in wind power:
Wind Energizer: 150% Power Boost by Simple Wind Turbine Addon
Until now, in order to make more powerful wind turbines, you had to make longer blades, so they could capture more incoming air and transform it into mechanical work. LeviathanEnergy, led by dr. Daniel Farb, has refreshed this approach towards increased efficiency not by increasing the blades, but by making the wind hit them differently.