A team of researchers from MIT and RWTH Aachen University in Germany have figured out how to make solar power plants more efficient using a design inspired by what might be the most efficient solar panels of all: flowers.
The solar power plants that are located in the middle of the desert aren’t just collections of solar panels. Instead, concentrated solar power plants use large arrays of mirrors to reflect the sun’s light to a central tower where it’s converted to heat, generating electricity. These plants can provide large amounts of clean energy, but they take up a huge amount of space. The Ivanpah Solar Power Facility in California, under construction now, will take up 4,000 acres. That’s more than four-and-a-half times the size of Central Park.
Alexander Mitsos, the Rockwell International Assistant Professor of Mechanical Engineering at MIT, led the research. Mitsos’ lab developed a computational model to evaluate the efficiency of various mirror layouts. What the MIT researchers figured out was that by arranging a CSP plant’s mirrors in the same spiral pattern as appears on the head of a sunflower, they could pack the mirrors more closely while minimizing shade. The result: They could reduce the "footprint" of a CSP plant’s mirror array by as much as 20 percent and at the same time increase the energy the plant generates. The researchers published their results in the journal Solar Energy.
Mitsos explained the benefits to MIT News, saying, "If we’re talking about going to 100 percent or even 10 percent renewables, we will need huge areas, so we better use them efficiently."
The idea of biomimicry—borrowing design innovations from nature—has been getting a lot of attention recently, from TED talks to a new book by architect Michael Pawlyn. But we shouldn’t be surprised that sunflowers have something to teach us about solar power. They’ve been working on the problem for millennia.