The taller we build our cities, the windier they become. As we hunt for renewable sources of power generation why is this powerful and plentiful resource untapped? That is the question asked by the winners of this year's James Dyson Award, Nicolas Orellana and Yaseen Noorani from Lancaster University as they set out to harness urban wind with an inventive new type of turbine. For more information see the IDTechEx report on Self Powering Smart Cities 2018-2028.
Traditional wind turbines only capture wind travelling in one direction, but are very inefficient in cities where the wind is unpredictable and multi-directional. When wind blows through cities it becomes trapped between buildings, is dragged down to the street and is pushed up into the sky. This catapults wind into chaos, which renders conventional turbines unusable. Using a simple geometric shape, O-Wind Turbine is designed to utilise this powerful untapped resource, generating energy even on the windiest of days.
Nicolas Orellana first became interested in the challenge of multidirectional wind after studying NASA's Mars Tumbleweed rover. Six feet in diameter, this inflatable ball was designed to autonomously bounce and roll like tumbleweed, across Mars' surface to measure atmospheric conditions and geographical location. Like conventional wind turbines, it was powered by unidirectional wind blows which severely impaired the rover's mobility when faced with obstructions, often throwing it off course and resulting, ultimately, in the failure of the project.
By exploring the limitations of the Tumbleweed, Nicolas's three-dimensional wind turbine technology was born. Nicolas and his fellow student Yaseen Noorani soon identified how cities could use this technology to harness energy to produce electricity.
How it works
The turbine is of a spherical shape with a single axis of rotation going through it. Its dimensions and shape mean that it is very suitable for small-scale energy production by individual apartment dwellers e.g. by being fixed outside balconies. The turbine makes use of Bernoulli's principle for its mechanical motion. The structure is lined up with vents which have large entrances and smaller exits for air. In the presence of wind, there is a pressure difference between the two terminals causing the turbine to move. The vents are placed all across the sphere making it receptive to wind from all directions in both the vertical and horizontal planes. The turbine will rotate in the same sense about a fixed axis regardless of wind direction. This turbine rotation is used to power a generator that can produce electricity, which can be fed into the national grid, hence providing financial incentive to users and improving the region's sustainable energy production.
The initial technology was developed from the study of alveolar kites. Single square fabric kites in different proportions allowed the analysis of pushing forces when exposed to wind. These kites were then re-shaped, turned into faces of different polygons and tested in various configurations until the complete body would take winds coming from left and right to generate rotational movement, pushing the body forward. This body was combined with an external frame that translated the rotation into straight displacement. A 2mt prototype travelled over 7km. The later development added a second layer of channels with entrances from every direction to make it omnidirectional. This was made firstly by modifying the previous 3d model in different ways to achieve the same wind-redirection capacity from all faces. The best alternative was prototyped in cardboard and proved in several locations to try its new omnidirectional capability. The 25cm cardboard prototype was proved with hairdryers and fans to easily test its reaction to changing winds. The successful test demonstrates, in a very simple way, its capacity to keep rotating in the same direction even under rapidly changing winds. Further prototypes are being 3d printed for performance test in wind tunnels at the Lancaster University.
How it is different
The O-Wind, due to its unique design, makes use of wind approaching from all directions in 3 dimensions including wind in the vertical direction. This is not the case for other wind turbines in the market, with VAWT's being multidirectional only in the horizontal plane. The simplistic design and use of a single axis of rotation mean that no steering is involved, hence requiring less maintenance than traditional wind turbines. Finally, the size and shape of the turbine mean that it can be placed in different kinds of environment compared to traditional turbines which require more space. The O-Wind is well suited to urban environments hence widening the range of suitable locations for the harnessing of sustainable energy.
Further prototyping and tests will be made in order to optimize its performance. Specialized facilities have been made available at Lancaster University for this purpose. Beyond this solution, the technology can be used for developing on-grid and off-grid alternatives for the urban market as well as for motor homes, boats and other stand-alone applications at different sizes. One particularly interesting possible application is wave energy generation, as under the waves it is also a chaotic situation with water flowing in every direction. In order for this technology to be used in that scenario, a greater R&D effort should be made.
This is the first contest this technology is presented to, but the team leader has been awarded eight relevant awards, including the Santander Award (Chile 2009), the Iberoamerican Innovation and Entrepreneurship Award (Argentina 2010) and the Biomimicry Global Design Challenge (USA 2015/16).
Nicolas Orellana said: "We hope that O-Wind Turbine will improve the usability and affordability of turbines for people across the world. Cities are windy places but we are currently not harnessing this resource. Our belief is that making it easier to generate green energy, people will be encouraged to play a bigger role in conserving our planet. Winning the James Dyson Award has validated our concept, and given us the confidence to approach investors to secure the capital we need to continue turn our idea into a reality."
Source and images: The James Dyson Award