Researchers placed magenta solar panels above broccoli and found the plants used sunlight 4.5 times more efficiently while reaching similar final size and yield, although they needed 25 extra days to mature
What if the future of farming looked a little less green? In a Swedish experiment, rows of broccoli grew beneath unusual magenta-coloured solar panels, turning a patch of farmland into a test site for a different kind of agriculture. The idea was simple: let crops receive the wavelengths they need while using the rest of the sunlight to generate electricity. The results suggest that the arrangement could make plants surprisingly efficient at using the light available to them, states an online report by The Debrief.
A different approach to agrivoltaics
According to The Debrief report, the research was conducted by scientists at Mälardalen University in Västerås, Sweden, as part of a broader effort to understand how solar power and crop production can share the same space. It is stated thatAgrivoltaic systems typically place solar panels above agricultural land, allowing farmers to produce electricity while continuing to grow crops underneath. The panels can also offer protection from intense sunlight, heavy rain and hail. The problem is that conventional panels are largely opaque, potentially blocking too much of the sunlight crops require, the report adds. The Swedish team explored whether semi-transparent panels could solve that problem by filtering sunlight rather than simply blocking it. Broccoli was chosen partly because it is widely grown and nutritionally important, and because it can adapt well to the local Swedish climate.
Giving broccoli a tailored spectrum
For the 2024 growing season, researchers established two 20-by-20-metre experimental systems fitted with semi-transparent magenta solar panels. The panels varied in their transparency, allowing different amounts of sunlight to reach the plants.The colour was important. The systems were designed to increase the proportion of blue and red wavelengths reaching the broccoli, while using other portions of incoming sunlight for electricity generation, explains the online report.A separate plot exposed to normal sunlight served as the control. Throughout the growing season, researchers monitored conditions including air temperature, humidity and soil moisture. They also assessed crop yield, nutrient composition and photosynthetic performance. The results were striking as broccoli grown beneath the magenta panels used sunlight 4.5 times more efficiently than plants growing under direct sunlight. Despite receiving a modified light spectrum, the plants ultimately reached a similar size and produced comparable yields. There was, however, a trade-off: the panel-grown broccoli needed about 25 additional days to reach maturity.
Electricity and food from the same field
The findings point to one of the central attractions of agrivoltaics: the same piece of land could potentially produce both food and renewable energy, states The Debrief report. Electricity generated by panels could be used to operate irrigation systems, agricultural machinery, refrigeration and storage equipment, or potentially be supplied to the wider power grid. At the same time, the panels could provide crops with a degree of protection from extreme weather and excessive sunlight.The technology tested in Sweden remains experimental, however. The magenta panels used in the study are not currently commercially available, and the researchers stressed that crop responses could vary according to climate, panel design and growing conditions.
The next generation of solar farming
The team is now investigating which combinations of panel colour and transparency can produce the best balance between plant growth and electricity generation. Experiments involving red and blue panels are also being conducted under controlled conditions, adds the report. For now, smaller applications such as community gardens or greenhouse roofs may be more realistic than covering vast agricultural fields.The bigger idea is to rethink sunlight not as a single resource that belongs either to crops or solar panels, but as a spectrum that can potentially be divided between both. If future systems can get that balance right, farms may one day harvest two crops from the same sunlight: vegetables from the soil and electricity from above.Image Courtesy: istock
