The broccoli heads sat low under a canopy that glowed pink instead of letting the sky through.<\/p>\n
Above them, rows of tinted glass caught the Scandinavian daylight and bent it toward rose.<\/p>\n
Nothing about the plants looked stressed or starved.<\/p>\n
They just took their time.<\/p>\n
Weeks after an open field crop would have been cut, these heads were only closing in on full size<\/strong>.<\/p>\n The question was what that delay bought the people standing beneath the panels.<\/p>\n The trick sits in the glass itself. Engineers at M\u00e4lardalen University in Sweden, working with Italian colleagues, built thin film cadmium telluride panels tinted a deep magenta. The magenta colored panels<\/strong> were customized to transmit more blue and red light, corresponding to the major absorption regions of plant chlorophyll pigments<\/strong>.<\/p>\n A leaf soaks up blue and red and bounces back more of the green, which is why plants look green in the first place. A magenta filter does the reverse, passing red and blue to the crop and holding back the green band.<\/p>\n Most agrivoltaic hardware is opaque and manages only how much light reaches a crop. This design tries to manage which colors arrive, not just how much.<\/p>\n “The basic concept is quite straightforward,” says Silvia Ma Lu of M\u00e4lardalen University, describing panels that take part of the incoming sunlight for electricity and let part of it pass through to the plants below. The canopy was never a shade cloth with solar cells bolted<\/strong> on, but a filter built so the plant and the power system could split the same beam.<\/p>\n At harvest, heads grown under the two tinted canopies averaged roughly 6.1 and 5.9 ounces<\/strong>, against about 6.6 ounces for broccoli left in the open. The gap is real but modest, and the authors conclude that growing under the panels did not substantially reduce head biomass.<\/p>\n What slipped was the calendar. Broccoli under both canopies matured 25 days later<\/strong> than the unshaded control, well past when an open field planting would have been cut and sold.<\/p>\n The two shaded plots produced heads of similar nutrient composition to each other, suggesting the degree of shading mattered little to what ended up in the florets. Against full sun the picture is less tidy, since the study reports that the panels affected nutrient composition<\/strong> along with microclimate and photosynthetic performance<\/strong>.<\/p>\n The trial ran through the 2024 growing season at K\u00e4rrbo Pr\u00e4stg\u00e5rd, a farm in central Sweden. Each canopy measured roughly 13 by 16 feet<\/strong> and stood on posts about 5 feet above the rows, one built from panels rated at 50 percent transparency and the other at 70 percent, with a third plot left under open sky as the control.<\/p>\n Every plot held 44 Marathon broccoli plants, transplanted in early July and protected by white insect netting, while the team logged air temperature, humidity<\/strong>, soil moisture and light quality throughout, as pv magazine<\/a> reported.<\/p>\n Measured at the crop, the two canopies passed only about 13 and 19 percent of the growing light available in the open. Heads under the panels were ready 104 days after transplanting<\/strong>, against 79 days in full sun.<\/p>\n That patient style of monitoring turns up elsewhere in the field, from a former coal mine<\/a> site running three crop layouts under panels to work that soaked a retired turbine blade<\/a> through repeated testing rather than a single measurement.<\/p>\n Here is where the headline number comes from. Light use efficiency, meaning biomass grown per unit of light intercepted, rose sharply compared with the unshaded plants, climbing between roughly two and a half times and four and a half times<\/strong> higher. That ratio climbs steeply when a crop keeps producing on a fraction of the light, which is what happened under the tint.<\/p>\n Why it held up is less settled. The canopies lowered the vapor pressure deficit<\/strong> beneath them, easing the water stress that slows photosynthesis on bright days, and the authors offer that as a likely contributor rather than a demonstrated cause.<\/p>\n Combining crop and electricity, the published study<\/a> puts the land equivalent ratio at an estimated 1<\/strong>.18, meaning the combined output beat separate plots of crop and solar.<\/p>\n None of this means a Nebraska soybean field is about to turn pink. Ma Lu calls the installation a prototype, and says it represents one of the largest published open field experiments so far involving semi transparent, colored solar panels in agrivoltaics.<\/p>\n “Configurations similar to our prototype may currently be suitable for smaller scale applications, such as community gardens, or for integration into greenhouse roofs rather than immediate deployment over large agricultural areas,” said Ma Lu.<\/p>\n The modules were commercially available thin film hardware of the kind made for building integration, then customized for the trial, so the magenta coating<\/strong> is not an exotic laboratory one off. The team has since moved to tighter indoor work on magenta panels and on panels that transmit red or blue alone.<\/p>\n Whatever crop comes next, the field in Sweden has shown that a tinted roof<\/strong> can feed a plant and a power meter at the same time, just not on the same clock.<\/p>\n","protected":false},"excerpt":{"rendered":" The broccoli heads sat low under a canopy that glowed pink instead of letting the sky through. Above them, rows of tinted glass caught the Scandinavian daylight and bent it toward rose. Nothing about the plants looked stressed or starved. They just took their time. Weeks after an open field crop would have been cut, … Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":46183,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"magenta tinted solar","rank_math_title":"Broccoli grown under 2 shades of magenta tinted solar panels in Sweden reached nearly full head weight, but took 25 extra days and used light far more efficiently","rank_math_description":"A Swedish agrivoltaic trial grew broccoli under tinted magenta solar panels, finding nearly full size heads, a 25 day delay and far sharper light use effi","footnotes":""},"categories":[8],"tags":[],"class_list":["post-46180","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-energy"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/46180","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=46180"}],"version-history":[{"count":1,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/46180\/revisions"}],"predecessor-version":[{"id":46184,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/46180\/revisions\/46184"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/46183"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=46180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=46180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=46180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Tinted glass tuned to the colors a leaf actually uses<\/h2>\n
Heads reached near full weight but ripened 25 days late<\/h2>\n
A season long trial across 2 canopies and one open plot<\/h2>\n
Light use efficiency jumped under the deepest shade<\/h2>\n
The prototype suits gardens and greenhouses, not open farmland yet<\/h2>\n