The “Soundscraper” would be a state-of-the-art structure which converts the noise and vibrations a city produces into sustainable energy. The design of the structure was put together by Olivier Colliez, Julien Bourgeois, Romain Grouselle, Cedric Dounval and Savinien de Pizzol as their entry in this year’s eVolo Skyscraper Competition.
The structure would essentially be a skyscraper with an envelope of noise-sensitive cilia to absorb the kinetic energy from urban noise for energy generation. The noise-sensitive material would cover the building in a double layer which would hang on a metal framework a little distance from the external surface of the skyscraper itself. The structure would be located in areas where noise pollution is highest, such as railway junctions and motorways.
Each Soundscraper would feature 84,000 electro-active cilia on the envelope help up by the metal frame to detect noise produced by pedestrians, cars, passing airplanes and trains. Each cilia would also be covered with Parametric Frequency Increased Generators, as the sound sensors are called. On detecting sound, a connected energy harvester transforms the vibrations into kinetic energy which is further converted to electricity by transducer cells. The electricity generated can either be connected directly to the grid or stored for future use.
According to the designers, one Soundscraper could generate approximately 150 MW of electricity (roughly 10% of Los Angeles’ lighting needs) in a heavily populated city. This means the city’s carbon emissions would be reduced. And with a few Soundscrapers, a significant percentage of a city’s electricity can be generated through this sustainable method to all but eliminate fossil fuel-based energy generation.
The building has a cylinder shape, but IS NOT a cylinder, as you can see from the picture. It is a rather porous surface that has a much larger contact area and gathers much more of the sound energy. If you’ve ever lived in a quiet suburb you know how the city sounds like from a in rush hours… you can clearly see there’s a lot of sound pollution coming from it, audible even at 10 miles away.
OvidiuSandru Yes, the area of contact with air is much larger than the area of the enveloping cylinder. Still, the acoustic energy can only enter the soundscraper through the cylinder surface. Having internal cilia can only helps to avoid wasting energy by reflection.
There is no known physical phenomenon by which any form of traveling energy can enter a closed surface at a rate greater than the flux density integrated over the surface. This is like to say that at any given time a teather cannot contain more people than those who entered the doors.
Nor can the acoustic energy permeating the open air magically be attracted towards the soundscaper. Anyway, 300000 cars produce at most 3 MW of acoustic power, there is no way to harvest 150 MW from that.
But let’s suppose that there is some clever way to collect all the acoustic energy at the soundscraper. The soundscraper would be able to produce at most 3 MW of electric power, and you would be unable to speak to someone near you, especially when your listener is located in the opposite direction in respect to the soundscraper.
Marco ColettiYou may have a point, but usually the truth is somewhere in between. I have seen many such projects come and go, and the few that succeeded usually didn’t rise up to their original claims, but somewhere in the middle-lower part of their initial estimate.
Totally unrealistic.
One car gives off at most 10 W of acoustic power. There are about 300000 cars traveling in a big city (20 km diameter) at peak hours.
This is to say 0.000956 cars per square meter, or an acoustic power density of 0.00956 [W/m^2].
Given that the city is much larger than the soundscraper, it can be assumed that the acoustic field is uniform and has about the same intensity as the field generated by an infinite plane of acoustic sources.
Therefore the acoustic power density arriving at the soundscraper is also 0.00956 [W/m^2].
But, every single point on the soundscraper surface can see only half the surrounding circle, hence the acoustic power density landing on every point is 0.00478 [W/m^2].
If the soundscraper is a cylinder having 40 meters diameter and 200 meters height, its surface area is 25120 [m^2].
Finally, the total acoustic power that can be harvested is only 25120*0.00478 = 120 [W].
More like 150 W than 150 MW.
Put one next to a Mosque and make use of all that noise it makes 5x/ day.