Have you ever walked on the sidewalk of a busy street and felt a gust of wind as a car rushed past you? Or maybe you’ve driven on the interstate and had a semi-truck speed past you, and you could feel the wind push your car? Both of those instances occur due to the same kinetic energy that is present in all wind, this energy just so happens to be produced by cars disturbing the air around them and not through natural causes. So, if we are already creating this kinetic energy as a biproduct of our transportation, then that is just wasted energy. If you’re following and agreeing with my train of thought, then your jaw should drop, like mine did, when I read about vertical axis wind turbines being used on highways and interstates to capture this lost energy and convert it usable electricity.
Vertical wind turbines operate in a very similar fashion to the traditional, windmill inspired horizontal axis (HA) wind turbine. The only material difference for the purpose of our conversation is the shape of the blades and the space they use. Unfortunately, vertical axis (VA) wind turbines generate less energy than their HA counterpart. It is because of this reason that we see wind farms all consisting of HA turbines. However, there is one area in which the VA turbine is superior, area. The blades of a HA wind turbine take up an enormous amount of space in its rotation. The diameter of an HA wind turbine is typically between 130 and 300 feet. Now its not hard to imagine that it may be difficult to fit a wind turbine of even the smallest size in the median of a highway. However, with a VA wind turbine, longer blades (to capture more wind) could still fit in these tight spaces as the blades’ rotation would not interfere with traffic.
Another key benefit of the VA turbine is that it can capture wind coming from every direction. Where a HA needs to rotate towards the wind in order to capture energy. A VA wind turbine has the ability to capture energy from 360 degrees. This would mean that during a busy day, the rush of air from both direction of traffic could be captured. Additionally, if only one lane was being used, hypothetically traffic headed towards an event, then the VA turbines could capture the energy going in that direction while also not forgoing the occasional driver headed in the opposite direction. Additionally, a VA turbine can also capture the energy from a single passing car late at night regardless of what direction they are coming from. Also, I should clarify that these turbines are not stand-alone installments but are installed in rows headed down long stretches of roadways.
One might ask, is this method of energy capture renewable? Absolutely, as long as there are cars on the road, this energy source will be constantly replenishing. Is this a green energy source? Well, that depends on how you view this issue. You could argue that since most cars are fossil fuel combusting that this in fact is not a green source of energy as the catalyst for this process is carbon producing. I will say that its not as carbon producing as it is carbon mitigating. For example, we already talked about how electric vehicles (EV) are 20%-60% cleaner than their combustion counterparts. If an EV is in part powered by a highway turbine and then drives on that same highway spinning that turbine again it becomes a cycle that can recuperate some energy lost in the process from the previous step. Is this going to solve all our energy needs, and will we be able to drive EVs around wind turbines to produce electricity infinitely? I’m going to go out on a limb and say absolutely not. But I think that the benefits of mitigating carbon emissions already being produced and creating an efficiency where only waste currently exists make this an idea worth looking into a bit further.
Do you think we may see VA wind turbines dotting US highways? Comment below.