Wind power. I’ve been looking at wind turbines and there are some great ideas out there.
Almost every wind turbine I’ve seen has thin blades and attach directly to the generator. These are only efficient at a specific RPM. If you were able to build a wind turbine with a low loss gear box, that could smoothly and quickly change gear ratio, you could use larger blades and more of them. It would startup at a lower wind speed and have more torque.
When I saw the NuVinci hub, I knew it was just what was needed. The NuVinci is a continuously variable planetary (CVP) transmission. By tilting the axis of balls between two rings, the NuVinci is able to create an infinitely variable gearing ratio.
The NuVinci appears to have been create for bicycles. If it works well enough for a human powered vehicles, it should do well with wind power.
(image from Fallbrook Technologies website)
The National Renewable Energy Lab comissioned a study, published in August of 2005. Here is a PDF link to the study. The study concluded that using the NuVinci CVP would save cost and product more power.
I am looking forward to some really interesting developments in wind power…