Vertical Axis Wind Turbines

So we've all seen Horizontal Axis Wind Turbines aka big propellers that create electricity. And those are cool, but they seem to suffer from a scaling-down problem that makes them a little hard to on top of buildings, specifically - which is where the vertical axis kind come in.

But first, an interesting question: is there even any worthwhile wind on top of buildings?

One widely-quoted expert, Mike Sagrillo, says in an interview with Mother Earth News, not really.

The wind trips over obstacles, and when it trips, the wind can’t do the work it could have done without the obstacle. You’re creating turbulence and diminishing the quality of the wind resource. With wind, we’re dealing with quantity, yes, but we’re also dealing with quality. You want a nice fluid flow, not turbulence.

It's certainly a problem - and the greatest wind resources are, as a recent trip to Arizona and New Mexico anecdotally confirms, out in smooth, flat-but-not-too-flat land.

The whole interview is, essentially, a condemnation of vertical axis wind as something useful (at the moment, anyway). In general, Sagrillo - a small-wind columnist and expert with some long-term experience - believes that the scientific and engineering work hasn't really been put into creating vertical axis stuff that's worthwhile; in addition, issues of basic physics reduce the efficiency of vertical axis stuff about 5% (with horizontal axis stuff generally around 35% efficient in terms of getting power from wind, vertical axis is about 30% efficient). Not only that; generally, because vertical axis stuff looks so cool (and it does), most vertical axis turbines tend to be a little scammy. On the American Wind Energy Association website, Sagrillo wrote a column about a study of urban/residential wind turbines that compared actual power generation to what the manufacturers predicted it would be. In general, the performance is depressing - except for the turbines installed on top of buildings. (It's worth noting that these are horizontal axis turbines, I believe - I bring it up to illustrate the scam-ful nature of some wind turbine companies, and to illustrate that while the manufacturer numbers are based on a computer model, the model breaks down in urban settings.)

Which is kinda a drag, because - in my opinion - vertical axis wind power in an urban setting is one of the keys to creating a society not only capable of mitigating climate change but also continuing that work towards a profoundly different, more sustainable society.

But, fortunately for my own soul, my university has been helping with some cool work to actually create a relatively cheap, efficient vertical axis turbine. Not only have they made it (locally and quite sustainably, too), but they're set to testing the hell out of it with the help of several public organizations in Portland.

The HE-100 Wind Turbine has some benefits over a more conventional horizontal axis wind turbine. It takes up much less space, is capable of being stacked or set up right next to each other (remember, urban setting) and doesn't kill birds. According to the makers, they don't create the sort of vibrations and noise that would kill any practical urban application. And they may start to overcome one of essential problems with urban wind generation - the weak and turbulent winds created by a landscape broken by buildings - because they start producing electricity in 5mph winds, and unlike horizontal axis designs, are capable of utilizing wind that changes directions quickly.

Plus they're bright green and made from a lot of recycled material. Cool.

So anyway, I'm talking these things up a lot. There are two reasons; first, Portland State pride! Go Vikings? Or a mandate embracing both intelligent urban planning and sustainability, anyway (motto: in urbi serviat, let knowledge serve the city, cool stuff). The second and much more pressing reason is that this vertical axis wind turbine starts to break the conventions that Sagrillo talks about in the interview above; specifications on the turbine are publically available, and extensive testing will occur with units installed on Portland State University buildings and new Trimet facilities (Trimet is Portland's mass transit authority).

But more than that, this wind turbine - and others like it that are no doubt being research and created - represents something that I think is important. In the interview and other material, Sagrillo talks about how basic, physical laws mean that vertical axis wind turbines are a little less efficient and little harder to take care of than horizontal axis stuff. That may be true - I don't honestly know if the HE-100 design, or any other vertical axis design, stands up to that.

But at the same time, that product was conceived and is being built for a single purpose - to bring power generation to where the electricity is needed. In terms of pure numbers, a giant wind farm in the middle of nowhere (meaning, of course, the middle of a non-urban ecosystem) may produce more electricity out of the same amount of wind - and perhaps for less money - even counting the cost of transmitting power long-distance.

Yet, local power generation is important. It's the greatest step we can take to break away from both foreign energy (which is not just oil) and retreat from environmental destruction. The way I see it, proposing that climate change mitigation can only be accomplished with massive solar and wind installations is missing one of the points of climate change mitigation. Yes, there's a concrete target - 450 by 2050 - that will achieve important results, but we need to start looking beyond that. Climate change means not only human suffering, but massive environmental damage; are we short-sighted enough to continuing destroying the environment to achieve mitigation?

I don't know the numbers as well as a lot of people. It may well be possible that our only hope is huge installations in protected wildlife areas. We may have to make a devil's bargain to beat the heap-of-mistakes passed down to us by previous generations.

But one thing that won't change, regardless of whether or not we reach 450 by 2050 and start mitigating climate change, is that humanity needs a new paradigm. Not just respect for species (by not extinction-ing them) or respect for individual, picturesque ecosystems, but a respect for all ecosystems - including human ones. The only way we can achieve that given the growth of population and energy needs in the world is to start making the most of our cities - places where we've already paved over nature.

And the key to doing that is, first and foremost, local power generation. Vertical axis wind is one of those things. Whether or not a vertical turbine on top of a building works as well as a huge propeller on top of a hill somewhere - I'm not convinced that that matters as much as people think it does. I think the biggest thing is that we're using our cities well - they're starting to produce something, rather than just consume.

And hey, it is Portland State. Go Vikings.