Video - "We have demonstrated that 'smart greenhouses' can capture solar energy for electricity without reducing plant growth, which is pretty exciting," said Michael Loik, professor of environmental studies at the University of California, Santa Cruz, and lead author on a paper that appears in the current issue of the American Geophysical Union's journal Earth's Future.
Electricity-generating solar greenhouses utilize Wavelength-Selective Photovoltaic Systems (WSPVs), a novel technology that generates electricity more efficiently and at less cost than traditional photovoltaic systems. These greenhouses are outfitted with transparent roof panels embedded with a bright magenta luminescent dye that absorbs light and transfers energy to narrow photovoltaic strips, where electricity is produced. WSPVs absorb some of the blue and green wavelengths of light but let the rest through, allowing the plants to grow. WSPV technology was developed by coauthors Sue Carter and Glenn Alers, both professors of physics at UC Santa Cruz, who founded Soliculture in 2012 to bring the technology to market.... "Plants are sensitive not just to the intensity of light but also to color, but it turns out the plants grow just as well."
Loik's team monitored photosynthesis and fruit production across 20 varieties of tomatoes, cucumbers, lemons, limes, peppers, strawberries, and basil grown in magenta glasshouses at two locations on campus and one in Watsonville, California.
"Eighty percent of the plants weren't affected, while 20 percent actually grew better under the magenta windows," said Loik. Tomatoes and cucumbers are among the top greenhouse-produced crops worldwide, he said.
Greenhouses use electricity to control temperature and power fans, lights, and other monitoring systems. "This technology has the potential to take greenhouses offline," said Loik, who specializes in climate change, plant physiology, water resources, and sustainable technologies. Cost per panel of WSPV technology is 65 cents per watt—about 40 percent less than the per-watt cost of traditional silicon-based photovoltaic cells.
"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."
Supporting data for Loik et al. 2017 Wavelength-Selective Solar Photovoltaic Systems: Powering greenhouses for plant growth at the food-energy-water nexus. Earth's Future
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