Researchers at the University of California, Santa Cruz (UCSC) have created a magenta-colored greenhouse with integrated solar panels that allows it to produce electricity while growing plants more efficiently. The combined technologies could make greenhouses self-powering, according to the university’s research.
The greenhouse panels are made of transparent plastic panels with a luminescent dye. The dye absorbs light and transfers it to narrow strips of photovoltaic cells, producing electricity. The combination didn’t negatively affect the growth of plants in the greenhouse and actually increased production for some plants, while overall reducing the amount of water needed to produce them. The researchers published their work in American Geophysical Union's journal Earth's Future.
"We have demonstrated that 'smart greenhouses' can capture solar energy for electricity without reducing plant growth, which is pretty exciting," said Michael Loik, lead author of the study and professor of environmental studies at the UCSC. "Eighty percent of the plants weren’t affected, while 20 percent actually grew better under the magenta windows," he explained.
"I thought the plants would grow more slowly, because it's darker under these pink panels. The color of the light makes it like being on the Red Planet," said Loik. "Plants are sensitive not just to the intensity of light but also to color. But it turns out the plants grow just as well."
In three greenhouses, two on campus and one in Watsonville, CA, the researchers grew and monitored 20 varieties of tomatoes, cucumbers, lemons, limes, peppers, strawberries, and basil. The tomatoes also required 5 percent less water to produce the same amount of fruit.
The greenhouse used Wavelength-Selective Photovoltaic System (WSPV) technology. According to UCSC the system generates electricity more efficiently and at less cost than traditional photovoltaic systems. The system in this case absorbs some of the blue and green wavelengths of light but let the rest through.
The researchers said that the use of greenhouses to produce food has increased six-fold over the past 20 years and is expected to increase more. Hence reducing the amount of energy used by greenhouses is important. "If greenhouses generate electricity on site, that reduces the need for an outside source, which helps lower greenhouse gas emissions even more," said Loik. "We're moving toward self-sustaining greenhouses."
That technology, which costs 65 cents per watt is about 40 percent less expensive than other photovoltaics, according to UCSC. It was developed by Sue Carter and Glenn Alers, both professors of physics at UCSC and coauthors of the research. They founded a business, Soliculture in 2012, to bring the technology to market.Tweet