Get Smart about Energy™


Over the past year it has been my lot to write (not bloviate) on energy saving technologies that sound useful, but are in reality little more than 'near scams'. As we draw to a close in 2010, it is frustrating to reflect on how much traffic is generated by energy saving scams compared to articles on energy attitude or how to conduct a basic energy audit.

DDFTTW So you might imagine my pleasure at being sponsored by Edge Consulting to attend a presentation hosted by the American Institute of Aeronautics and Astronautics (AIAA) San Francisco Chapter titled - Directly Downwind Faster Than the Wind.

I assumed that an event hosted by the AIAA would be scientifically sound and looked forward to understanding how this unlikely sounding phenomenon, to go Directly Down Wind Faster Than The Wind (DDWFTTW) would be explained. I had little idea that I was entering a hot bed of academic contention, a topic having a long and distinguished pedigree, or that it would result in the first ever "Not a Scam Review" by Open4Energy.

DDWFTTW was first tested by the late Andrew Bauer. Andrew Bauer was not the original inventor of the concept, but did build the first successful DDWFTTW cart that anyone knows of. He did this to settle a friendly wager with a colleague and notable aero engineer A.M.O. Smith in 1969. The wager was based on a claim in a student's paper, written 20 years before, that DDWFTTW should be possible.

I began to understand better - how something could go directly downwind faster than the wind - when I realized that the question was not about wind speed, but rather one of conversion of kinetic energy potential. In this case using a propeller to convert the energy potential in a volume of air moving at a speed (wind) into a force that could be applied to wheels.

The good news is that I was not alone in grappling with this shift in perception. Knowing that this was likely to be the case, Rick Cavallaro, Chief Scientist, and John Borton, Director of Manufacturing, both at Sportvision, Inc. came prepared. Having no wind in the building to work with, we used a treadmill running at speed to create an energy potential. The model carts wheels would drive the propeller, and generate a force that allowed it to exceed the speed of the belt. It worked! After a few adjustments to 'direction' the cart was soon moving faster (in the opposite direction) than the belt. It did prove the point, but only after an additional layer of mind gymnastics had been digested.

But, having seen the cart with propeller actually going faster than the belt, we were ready to watch the video of the real 'cart', sponsored by Joby and Google, doing its thing in the dessert.

Wow! - If you do not visit the web site (click image for video - this link for project web page) Ride Like the Wind (only faster) you will truly miss out. Be patient when watching the video, it takes a minute or so for the 'cart' to pick up speed, but once it gets going it really gets going.

The comments on YouTube will give you a sense of the controversy. I have included an extract (see below) from Richard Jenkins - world land speed record holder - who went to video the 'failure', and has had the good grace to admit to his early opinions. Skeptics, please note that NALSA (North American Land Sailing Association) were responsible for validating the conditions and results of the test.

"So, one night, I was happily drinking my beer and tending to my inbox of endless boring emails that had be answered but were of no real consequence, when Lester, my landsailing buddy texted me a link to Lester knows a lot, and if he says this needs my attention, then it gets it. I am not sure if it was how many beers I had had, or simply the inane nature of the quest, but I laughed enough to email all my friends to share the absurdity of their mission. My heart is split between belittling idiots, and saluting eccentrics, and this downwind quest lay somewhere in the middle. These loonies were pursuing a pointless goal, doomed to failure, but there was some genuine merit in the myth and their enthusiasm.
I dismissed it as utterly impossible. Traveling through zero apparent wind, with no stored power? Impossible. Why would you even attempt it? (Though I'm no stranger to that question myself!) But had I been asked to bet at that moment, I would have just lost a lot of money.
A few months later I actually met the idiots in question and, to my surprise and concern we not only have a few mutual friends, but they seemed to be rather technically credible. But, everyone makes mistakes, and I let them off as decent people with a blinkered view of fundamentally flawed engineering....
A few months later they were claiming success and if it was not for another great friend, Bob Dill, advising that they were actually correct, I would have discarded their claim as an April fool. I thought about the possibility that I was wrong, and then considered that as Bob was getting on a bit and had a bit of a shake with his stopwatch finger, maybe it was he who was mistaken. There was, however, a growing momentum of technical people (who should have known better), saying that these idiots have actually proven that it is possible to travel faster than the wind going directly down wind.
Not content, I had to witness this myself. When I heard it was on for the official record at El Mirage, I jumped on a plane and went to check it out.

Well there you have it! Well not quite, despite Rick's caution when I asked him about the practical value of this result. It turns out that wind energy potential can be more efficiently converted when using a propeller and movement. Unlike a wind turbine, where the wind potential is a function of the surface area of the blades, a moving propeller will use the wind potential contained by the 'tube' created by the area and the distance it moves through.

Hmmmm! Are we likely to see wind turbines running across our headlands soon. I seriously doubt this, although a wind turbine moving on tracks might be worth considering. But there is one 'cart' that moves in wind over long distances, only it is more commonly known as a container ship. It is early days, but there are container ships with dual electric and fuel oil driven propellers. It is not a far stretch to think of a container ship sailing downwind, making use of the increased energy potential of a propeller in a 'tube' of wind, downwind, that is being converted into usable electric energy.

My compliments to Rick and John for a stimulating evening, and my thanks to them for taking the time to discuss potential energy saving applications of this capability.


Open4Energy - Get Smart about Energy™