While we've all become accustomed to the most popular design for wind turbines – three great white blades suspended dozens of feet in the air, slowly rotating clockwise in the wind – there are limitations to this design. For the most part, these issues result in qualms about efficiency and thereby the overall applicability of wind-energy technology. Across the globe, engineers have been working to develop alternative takes on the wind turbine, and today there are several new designs being developed that offer the promise of more practical widespread use.
It's an exciting time in the wind industry. These new approaches could represent just what the wind energy industry needs to become a truly formidable force in the energy sphere.
The changing axis of wind energy
Engineers are altering the design of the wind turbine in hopes of creating a new approach able to capitalize on lower wind speeds. Doing so would make it possible for turbines to be used in diverse applications away from a traditional wind farm setup. The prevailing trend in this developmental search has been to flip the turbine design on its head – or more appropriately to flip the turbine's axis.
In industry-speak, traditional wind turbines are referred to as horizontal-axis turbines. Many of today's startup turbine companies are experimenting with vertical-axis turbines, which have long been deemed ineffective solutions by many industry experts.
However, new research produced by a team at the California Institute of Technology has breathed new life into the hopes of the vertical-axis turbine industry. Based on likening aeronautics to the properties of water displayed when schools of fish pass through an area, the team's findings suggest that deliberate and complementary vertical-axis turbine placement can improve the energy output of a wind farm exponentially.
The vertical axis of the turbine itself allows for a closer proximity between models because the blades are oriented vertically rather than splaying out to the sides. If the findings of this new research from Caltech are proven to be effective, it may help silence the many critics of vertical-axis turbines.
Why don't people believe in vertical-axis turbines?
In short, many industry leaders are skeptical of vertical-axis turbines because the designs are still grappling to produce numbers that clearly demonstrate they are more efficient.
One of the problems that faced the first vertical-axis turbines was the force brought to bear on the arms of the turbine itself. In a vertical-axis application, a turbine's arms are under a great deal of pressure from the basic forces of physics. Some of these limitations have been overcome by rethinking the shape of the blades themselves, making them more aerodynamic. Many models today mimic a helix design with curved blades to reduce their vulnerability to wear and tear.
Others in the industry dispute the vertical-axis turbine's usefulness in urban applications. Vertical-axis turbines are often sold under the premise that by requiring less wind to rotate, a vertical-axis model is more useful than its horizontal-axis cousin. Experts often call this statement into question because while it is true that vertical-axis turbines are able to harness energy from less powerful wind, these wind forces still have to be in the form of a consistent flow. The argument against many urban applications is that a steady flow of wind is simply impossible due to the interference of surrounding structures and other atmospheric turbulence.
The jury is still out on these new turbines, but as the market continues to experiment with vertical-axis solutions we're sure to get a better idea of their overall viability.