Every now and then, an idea comes along and it makes you wonder why no-one else thought of something so simple. This time, it’s solar-powered greenhouses, which do exactly what you’d expect.
Writing in the journal Earth’s Future, Michael Loik – an environmental researcher at the University of California Santa Cruz – explains that his team has officially grown their first crops of tomatoes and cucumbers in one of these prototypes. As hoped, they’re just as healthy and nutritious as those grown in conventional greenhouses.
“We have demonstrated that ‘smart greenhouses’ can capture solar energy for electricity without reducing plant growth, which is pretty exciting,” Loik said in a statement.
Loik’s greenhouse works a lot like a regular one, in that its design traps in light and heat, and keeps plants at their optimum temperature and humidity. There are, however, some incredibly bright red-magenta panels adorning its roof, which actively soak up the sunlight and generate electricity.
Greenhouses are fairly energy intensive, so finding a way to reduce their electricity costs has been a long time coming. Solar panels have been touted before, but normal ones would simply stop light coming through and getting to the plants – a rather difficult roadblock.
In order to get around this problem, Loik and his team decided to use specialized versions named Wavelength-Selective Photovoltaic Systems (WSPVs), a fairly new technology that generates electricity more efficiently and cheaply than regular photovoltaic systems. They also happen to let light through, albeit only certain wavelengths, which could have potentially disrupted the plants' ability to photosynthesize.
In order for these clean energy greenhouses to be viable, Loik had to make sure that plants still grew properly under these pink-hued shades. Using 20 varieties of crops – tomatoes, cucumbers, lemons, limes, peppers, strawberries, basil, and more – it was found that 80 percent of the flora grew just as they did within conventional greenhouses.
Curiously, 20 percent grew better, although it’s not yet clear as to why – particularly as less light gets through these scarlet-tinged windows. As an added bonus, crops generally required a little less water than they did in normal greenhouses.
“Although more research is required on the impacts of WSPVs, they are a promising technology,” the study concludes. Loik said that this research “has the potential to take greenhouses offline.”
Greenhouses require a substantial amount of power, particularly for heating, monitoring, and lighting during the darker hours of the day. Although they’re designed for something that’s literally green, their carbon footprint is likely a lot higher than most people realize.
Loik’s research hints at a better future, where “smart” greenhouses grow plants even more efficiently than they do now while fighting climate change at the same time.