Bladeless Turbine Technology For Wind Power Generation

The last two decades have shown a phenomenal increase of wind turbine industry, reaching the capacity of cover the 11, 4% of the EU electricity consumption in a wind year. More efficient turbine designs have been produced, but, despite this growth, it may have reached its limits because of social acceptance and costs. The alternative energy industry has tried to solve these issues through the introduction of bladeless turbines. Bladeless technology consists of a flexible cylinder mast attached to a fixed base. The cylinder oscillates on a wind range, which then generates electricity through an alternator system according to a phenomenon called “Vortex Shedding”.

The Vortex Shedding effect was first analysed and described by Theodore von Kármán, in 1911. This effect is produced by lateral forces of the wind on an object. The wind flow generates a cyclical pattern of vortices and when the frequency of these is close enough to object’s structural frequency, this starts to oscillate and, in some cases, it can collapse. One of such examples is the Tacoma Narrow’s bridge in 1940, USA. This catastrophe inspired David Yáñez, who founded a tech start-up called Vortex Bladeless in 201. During the years the project has developed and tested several prototypes that can be divided in three types: one 2, 75 meters tall with an energy production capacity of 100Watt and an estimated cost of 250$, a more advanced one 10 meters tall with a production capacity of 4KW and another one 149 meters tall that can produce 1MW. This last two are still under development, while, concerning the first one, today Vortex bladeless plans to start a pilot program in India and reach the market in 2019.

Even if there are various possible turbine designs, the majority of turbines nowadays are built in an upwind horizontal-axis design with three blades. The wind blows through the blades, converting wind's energy into rotational shaft energy. This type of turbines has to face several problems in some applications regarding social acceptance and cost efficiency that seems very hard to get around. In particular, the first can be divided in: scale and aesthetic impact on the landscape, noise and impact on fauna. Wind turbines are big and they are getting bigger in the future in order to get higher level winds and efficiency. Many current models have blade diameters of around 100–125 meters, and recently developed ones have diameters around 160 meters. Such installations can completely affect the local landscape, especially when multiple turbines are installed together in the same area. Concerning the noise, the most relevant source is the aerodynamic which can release an average output of 105 dB for many models recently, but the largest new models released can reach 110 dBA in 10m/s winds. It has been estimated that this level of noise contributes to stress and headaches. Another social acceptability issue is the impact on fauna, especially birds. Flocks of birds fly across the blades and some of them are hit. It is assessed than fewer than 14 birds are killed per MW of installed capacity per year.

The aim of Vortex bladeless technology is to offer a new technology that can produce clean wind energy, overcame these issues and obtain cost efficiency. First because of its small dimensions and the absence of blades it may be less intrusive, making turbine’s installations and maintenance more flexible. Indeed, traditional ones need to change direction to be oriented with the wind stream, which operation requires time and energy cost, while the new technology, that has a circular shape, is always well oriented to wind and able to move without human intervention. Then, thanks to an oscillation frequency of the equipment below 20 Hz, the sound level impact is eliminated. Bladeless wind power’s impact on bird’s population is expected to be much smaller. Its design allows an oscillatory movement on bladeless turbines to be smaller than the one made by traditional ones, so it does not disturb wildlife and allows birds to have a higher visibility while flying. In addition to these benefits, it is expected to reduce manufacturing costs by 53%, operating costs by 51% and maintenance costs by 80% compared to traditional wind turbines thanks to a clever design, usage of raw materials such as carbon fibre polymers, plastics, steel, neodymium and copper and the elimination of nacelle, gears, brakes and blades, that are usual costly components.

Despite these benefits, field testing has demonstrated that the innovative turbine captures 30% wind’s power less than traditional ones, but this deficiency can be compensated by positioning more turbines into the same space. Indeed, the angle of oscillation of Vortex’s masts is around 5 degrees, which means that it can cover an area of 1m2 in total, while a regular one needs an area that is five times its height. The development of the innovative turbine and its unique features have been made possible only through a collaboration between Vortex Bladeless and different actors such as funding agencies, government, universities and other partnerships. Initially Vortex Bladeless was financed by private investors, supplemented by an Indiegogo crowdfunding campaign. Then the project gets additional financial support by the European Commission with Horizon 2020, the biggest EU Research and Innovation program ever with nearly €80 billion of funding. The prototypes have been tested on balconies and roofs of local houses in Gotarrendura, a small town in the “Castilla y Leòn” region in Spain thanks to the support of the regional government and public. Indeed, in Spain, unlike other countries, the decision regarding wind projects is made at the regional level.

Another fundamental group of actors that has been influencing the evolution of this technology is the one of research program. At the beginning the project participated with PRACE, a government-sponsored program composed of 25 European member countries that provides support for test plans, code optimization, simulations and evaluation of results with the help of a dedicated team of HPC experts. The success of this program has allowed to participate to a second one called SHAPE which support small organizations working on engineering challenges. Furthermore, Vortex Bladeless has established some partnerships with other companies in order to optimize the product. In particular Altair, a leading provider of enterprise-class engineering software, has conducted with Vortex a technical project to simulate the aerodynamic behaviour of the device. The computer-aided engineering (CAE) models made engineers able to predict the movement of Vortex Bladeless with different wind intensities. Finally, SEO/BirdLife, a representative organization of BirdLife International in Spain, that focuses on the defence of birds around the world, has signed a collaboration with Vortex Bladeless in order to reduce the impact on the fauna. Vortex bladeless collaborates also with different Spanish universities such as “Universidad Europea”, “Universitad di Cantabria” and “Universidad Politecnica de Madrid”, which provided the wind tunnel of their Microgravity Institute for all the first years of trials and helped the company with the data measurement.

The most relevant actors that can influence the project, even if they are not directly involved, in this case, could be the traditional turbine and the photovoltaic panels producers. Regarding the first, it is important to underline that they are not direct competitors, but they offer different features for different conditions. Traditional turbines usually require higher wind speeds for reaching their nominal power while Vortex could respond normally for common wind speed. Thus, their installation would depend on the area and its characteristics. Concerning the second, solar panels can be easily integrated with the innovative turbine, especially for residential installations, in order to get more constant and efficient power generation. Thus, thanks to this opportunity to connect the two energy investments, the project can encounter fewer barriers during his development and expand their possible customers. Policy and public have a crucial role concerning the diffusion of this kind of technology, since its implementation depends on the countries’ social acceptance and current laws. Several actions such as promoting local ownership, providing direct benefits or reducing perceived disbenefits could be conducted in order to further enhance its deployment and the community benefits. Local entrepreneurs can be involved for the construction, operation and maintenance of the turbines. Then, concerning the land owners, rental income or royalties could be established. In addition, the project should introduce some form of ownership and investment in the project among local people and/or some form of community fund, as for example single payment and annual payments. Finally, local inhabitants and mayors should have to be informed by the company through meetings about the planning of the project.

In conclusion, the new technology itself provides a possible solution to solve the issues of social acceptance and costs efficiency in some applications, but, at the same time, it is also necessary to not underestimate the role of the socio-technical system and continue to analyse its deployment, the relationship with the technology and offer participation in order to contribute to the development of wind energy.