By observing nature’s designs, scientists and engineers innovate mechanisms that increase the efficiency of the systems.
FREMONT, CA: Renewable energy nowadays means solar-paneled power plants and queue of windmills designed and installed by engineers to make energy generation more affordable to the planet and humans. But, the designs for these systems have existed in nature since before attention was drawn on it. As energy is the currency of life, the man-made processes which harness energy seem to showcase much efficiency when built with one of nature’s designs.
The imitation of designs and patterns from nature, or biomimicry, is an old concept that has remained in the background allowing the spotlight on the development. From bridges and buildings to water and waste management along with the food distribution and other examples, biomimicry establishments, technology, or products exist in different forms in today’s world.
Since renewable energy has gained more popularity, scientists and engineers are turning to nature for inspiration. Especially while designing the wind, marine, and solar energy devices in a method that increases the efficiency and reduces environmental impact.
• Solar Spirals:
The Gemasolar power plant operated by Torresol Energy comprises of 2,650 heliostats—a mirror-like instrument that can adjust its position to track the motion of the sun—fanning out around a central tower and reflecting the sunlight towards it. The central tower housed molten salts, which were utilized to store the energy harnessed from that light for extended periods. The arrangement of the heliostats follows the natural pattern as seen in the florets of the sunflower. This spiral pattern is called the Fermat’s spiral and is commonly found in the arrangement of leaves and flowers.
The researchers discovered that for a solar plant with a central tower, the efficiency of the heliostats nearest to the tower was higher. By arranging the heliostats in a Fermat’s spiral pattern, smaller footprint, and increased capabilities for the power plant was observed. The inspiration extended in-depth when each mirror was arranged in the golden angle of 137.5 degrees to its neighbor, avoiding any loss of radiation and blocking.
• Tapping the Tides:
Theoretical speaking, the energy harvested from the U.S. coast can supply power equivalent of about 66 percent of the electricity generated in 2017 by America, reports the U.S. EIA. To harness the energy from this vast source, inspiration was taken from a flapping flight of insects, birds, and bats to structure the oscillating hydrofoils.
An oscillating hydrofoil mimics an aircraft wing but is structured elliptically through its cross-section, allowing the harvesting of energy via its ebbs and flows. The structure heaves as a reaction to the tidal current, which generates a large amount of lift force, utilized for harnessing energy. The scientists believe that the heaving and pitching mimic the natural movements of the fish and aquatic animals, which is why it is much friendlier for the environment. The team has also showcased that the device can be scaled to work in shallow waters with correct placements.
• Inspired by Mud:
If the mud can withstand the energy carried by the waves, calm the waters and attract fish to the shoreline giving them a bountiful catch, then it is the way to go about in terms of offshore energy harvesting. This concept inspired a professor of mechanical engineering in California, Berkeley and has allowed him to create an artificial seafloor called the carpet. The idea not only helps reducing the cost for marine energy harvesting but also can be used for powering offshore aquaculture and seawater desalination.
The carpet absorbs energy like the mud does and then converts them into useable power for several applications. In California alone, the average generation of energy per meter of the coastline is 35 kilowatts.
• Fishy Turbines:
Researchers at Stanford University have drawn the patterns of fish schooling into the build of vertical axis wind turbine farms. To tackle the concerns from the horizontal axis turbine design from yesteryears, the bioengineers selected the fish schooling pattern because of its aerodynamic quality. The traditional windmills need to be spaced appropriately so that the airflow patterns which are formed by the first one would not affect the airflow pattern on the consecutive windmill’s performance. The fish schooling pattern resembles the movement of air generated behind the wind turbines. These movements rather than inhibiting the flow pattern of the neighboring fish, it enhances the flow. When fishes swim in co-ordination, the constructive interference of the flow among them minimizes the drag or the resistance to the airflow.
Similarly, turbines are placed in a vertical axis with staggered neighboring turbines that rotate in opposite directions. The placement makes it beneficial for the collective performance of the wind farm as the alteration of wind speed and direction by the adjacent turbines eases the process.
• Commercialization Challenge:
When it comes to improving the efficiency and economics of renewable energy, biomimicry offers in abundance. But, a significant impediment has been slowing down the pace of commercialization. The reason for lagging is complex and interconnected. Some reasons include the lack of consolidated test facilities for scientists to conduct the necessary trials. Difficulty in obtaining permits for testing in the ocean as new technologies cannot be assessed without designated test sites and dedicated funding from the industry and government.
Other significant issues include survivability of the technology is the harsh environments, the impact it causes on the surroundings. Since hardware development is inherently slow and costs a lot, scientists must work carefully.