December 19, 2011 |
Unique solar energy designs
Design is the adaptation of means to a pre-conceived end. The end can be purely for aesthetic purposes or to improve efficiency, functionality or a combination of all three. It has been said that the genius of Steve Jobs of Apple fame was his ability to combine technology and design. The seemingly benign and ubiquitous vacuum cleaner was revolutionized by Sir James Dyson, who after over 5,000 failed attempts
designed the “cyclonic” cleaner for a more beautiful and powerful product.
When considering the “design” of a solar energy system, whether for residential or commercial purposes, it is hard to envision anything other than a linear concept, that is, straight lines of solar panels arranged next to each other. However, recently several experimenters thought outside the box and came up with solar system designs that are anything but linear.
Seventh grader discovers more efficient solar design
First, Aidan, a 13 year old seventh grader from New York entered a contest sponsored by the American Museum of Natural History in an attempt to win the “Young Naturalist Award.” On a winter hiking trip in the Catskill Mountains of New York, he noticed that contrary to his belief that tree branches were nothing more than a tangled mess, he saw a pattern in the way tree branches grew. His research project studied the complex design of trees and how they “are more efficient than humans in collecting solar energy.” The more that young Aiden learned and experimented, the more he thought about creating a new way to arrange solar panels. In trying to understand the spiral nature of branches on different types of trees (i.e. oak vs. maple) Aiden concluded that the pattern of the branches followed the “Fibonacci” sequence as did many other forms of nature. He states: “I designed and built my own test model, copying the Fibonacci pattern of an oak tree……In place of leaves, I used PV solar cells hooked up in a series that produced up to 1/2 volt, so the peak output of the model was 5 volts. The entire design copied the pattern of an oak tree as closely as possible.” Aiden placed his solar Fibonacci tree model and a linear array in his backyard for two months. He found that the Fibonacci tree array captured 20% more electricity and collected 2 1/2 times more hours of sunlight during the day. Here
is a more detailed review of the project. You can read more about Aidan’s project here
as well. However, this claim of young Aiden has not been without controversy as it flies in the face, as some people believe, of common sense. For a review of the controversy surrounding Aiden’s project see this link
Jeffrey Grossman is an MIT power engineering professor. He states that standard flat solar panels are only “optimized to capture sunlight at one point of the sun’s trajectory-otherwise they need automated tracking systems to follow the sun.” In his attempt to increase the efficiency of the design itself of a solar array he turned to the ancient art of origami. He found that folded solar cell systems could produce constant power throughout the day and didn’t need tracking. He claims that his new designs are “up to 2 1/2 times more efficient per comparative length and width than traditional flat arrays.” ” Like young Aiden, Grossman was inspired by the way that trees spread their leaves in all directions to maximize their exposure to the sun. He worked with MIT graduate student Marco Bernardi to create a computer program that mimics the process of evolution. The computer program would randomize patterns of exposed surfaces and then choose the most efficient
one to start the next generation — how Darwinian.
What resulted were gorgeous sun-capturing shapes
that resemble origami. In some structures the surfaces also reflect
upon each other, intensifying the sunlight and increasing energy gain. Grossman noticed that the larger the shapes, the more effective the arrays were — sometimes they reached 120 KWh per day when a traditional array would generate 50 KWh. He is continuing his research to find the most effective folding patterns and has teamed up with Professors Vladimir Bulović and David Perreault of EECS to create a prototype system.”
I don’t think that we’ll be seeing these designs in the backyards of urban areas as traditional flat panel arrays seem more appropriate. However, I can envision some of these designs springing up in our future cities, where Fibonacci Solar Trees or Origami Solar Constructs represent a bold message that the 21st century will be the age of renewable power.