Generating Electricity with Bladeless Wind Turbines – One Household at a Time
An innovative wind turbine design from a small company based in Madrid and Ávila, Spain, started with a radical idea derived from a 75-year old catastrophe. Engineer, inventor, and co-founder David Yáñez encountered film footage of the infamous Tacoma-Narrows bridge collapse in 1940, caused by wind-induced vibrations and oscillations. That video led to Yáñez’s “Eureka” moment of inspiration: If wind power could create vibrational force and oscillations strong enough to destroy a heavily-built structure, what if the wind’s kinetic energy could be harvested safely to generate electricity – without big, noisy, bird-killing blades? The idea led Yáñez, and colleagues David Suriol and Raúl Martin down a path to found Vortex Bladeless (VB).
The team’s ultimate goal is to design a small (less than 3 meters high), inexpensive (less than $300) bladeless generator that will pump out electricity for individual households. Field testing of the new turbine is planned for later this year in India.
A bladeless generator, looking a bit like an elongated hourglass weighted at the bottom, could offer advantages over traditional turbine designs. First, without gears or other mechanical parts, bladeless generators would cost less to build, since they require fewer materials, and less to operate, since they required less maintenance.
Second, this oscillating pillar creates no audible sound, making it attractive in rural communities sensitive to noise pollution. Also, the absence of spinning blades minimizes harm to birds. And the tower’s small form-factor provides maximum energy generation from each patch of real estate. Finally, due to expected low maintenance costs and a simplified form factor, VB’s designs are projected to generate electricity for pennies per kilowatt-hour.
To fund prototypes and a pilot program, VB started its journey with private investors, supplemented later by an Indiegogo crowdfunding campaign, supporting research and development. Awareness of the bladeless concept spread, and backers helped VB exceed its initial financial goal. Complementing these investments, the European Union has made additional financial support available through the Horizon 2020 program, which has an €80 billion budget set aside by the EU to sponsor discoveries with potential societal, economic and environmental benefit.
Of course, funding is only a fraction of VB’s challenge. Working alongside Yáñez and several other technical experts at VB, Jose Viyeira, aerospace engineer and expert in fluid dynamics, took on the task of understanding the complicated physics behind the vortex effect and product designs. Achieving a useful prototype necessitated an HPC system capable of numerous advanced calculations.
“When we first explored the concept of a bladeless design, we started with a simple experiment – a small-scale wind tunnel test targeting a small plastic water bottle with a carbon fiber rod as the oscillator element,” said Viyeira. “In doing so, we sought to get a sense of interaction among the components as a starting point in the longer-term design process. No one ever succeeded in harnessing the elastic phenomenon with wind, which serves as the basis of our design, so we found ourselves in uncharted territory. We realized quickly that the dynamics of wind flow around the bottle is extremely complex to predict and quantify. We needed the help on an HPC system capable of extremely accurate modeling to create a workable, efficient, and scalable tower design.”
Currently, VB has working prototypes of bladeless designs one meter in height. Now it’s a matter of bringing more R&D effort, and HPC-powered CAE, to scale VB’s design into a fully functioning turbine.
“We are now doing physical wind-tunnel tests, and real-life models behave very closely to those found in HPC simulations,” said Viyeira.
When small towers are perfected, VB will begin work on taller designs. When a more powerful 2.75-meter version is built and tested in the coming months, VB plans to initiate a pilot program in a rural part of India where electricity is needed desperately. Today, those areas often rely on solar power. When the sun goes down, VB products can complement the solar panels, keeping battery banks charged and ready for use. The goal is for VB generators to enable smaller and less expensive batteries to be used in a household. In the longer-term, VB products pay for themselves with reduced energy creation cost. A small-sized 2.75 meter tower designed to help power a single dwelling will cost about $250 USD and deliver approximately 100 Watts.
Help from PRACE
Europe’s Partnership for Advanced Computing in Europe (PRACE) is a government-sponsored program spanning 25 European member countries. It provides academic institutions and corporations access to some of the world’s most powerful supercomputers and a dedicated team of HPC experts. Organizations apply for PRACE’s help, and once accepted, PRACE teammates partner with academics and scientists to provide support for test plans, workload evaluation, code optimization, simulations and evaluation of results.
The success of PRACE led to a second program, the SME HPC Adoption Program in Europe (SHAPE), which supports fledgling organizations like Vortex working on major engineering challenges. As with PRACE, SMBs apply for free HPC support through SHAPE.
While many projects tackled by SHAPE use a high-powered desktop system, the MareNostrum3 system in the Barcelona Supercomputing Center (BSC) was selected for the VB project. The November 2016 Top500.org ranked it number 129 with nearly 49,000 Intel Xeon computing cores plus Intel Xeon Phi nodes exceeding a petaflop at peak performance.
Noted Viyeira, “With PRACE’s help, we can do modeling and simulation that offers insights unavailable to us before. One thing we confirmed is that Vortex shedding – a natural effect in which circular movements of fluid come off a solid surface, and often cause vibration — is dependent on the Reynolds number, which describes the fluid flow characteristics. Thus, it is not a simple matter of proportionately scaling up a one-meter working prototype to a much larger structure.”
For these reasons, VB’s ultimate goal of a one-megawatt tower remains a longer-term plan. HPC simulations demonstrated that larger towers may need design modifications. Nuances must be identified and accommodated and the correct physics applied in the taller structures to ensure durability and efficient transfer of wind energy.
Using the data from HPC simulations, current VB designs consist of three main parts. The upper three-fourths of each Vortex Bladeless is a long, slightly-conical cylinder made from carbon fiber and balsa wood. This section serves as the oscillating portion, interacting with the wind and maximizing the vortex shedding effect for energy transfer. The carbon fiber tube extends to the bottom of the structure for additional rigidity and strength. The actual generator in the middle of the stack harvests the energy from the components around it.
Barcelona Supercomputing Center’s MareNostrum3 Vortex simulation tests of displacement over the bladeless generator (left) and resulting wind speeds in fluid (blue) are shown.
Asked about the future of his company, Viyeira said, “Our founders had a vision, and thanks to funding from Indiegogo contributors, private investors, partners, EU’s H2020 program, and incredible HPC support from PRACE we can realize our dream. A new idea has given us the unique opportunity to take a scientific journey, which we hope benefits people all around the world.”
Rob Johnson is the owner of Fine Tuning, LLC, a strategic marketing and communications consulting company based in Portland, OR.
