Rose-tinted solar panels let crops and power share land

Estimated reading time: 5 minutes · Last updated: 3 October 2026

Silvia Ma Lu of Mälardalen University tested rose-tinted, semi-transparent solar panels that pass most red and blue wavelengths while generating electricity. During the growing season those magenta panels generated about 224.7 MWh per hectare. Ma Lu grew broccoli (Brassica oleracea) beneath two panel setups — 50% and 70% transparency — on separate 20-square-meter plots and compared them with full-sun control plots. Total yields were comparable to full sun, but crops under the panels reached harvest 25 days later; measured light-use efficiency increased by a factor of 4.5 under the denser (50%) panels and by 2.8 under the 70% panels.

The basic concept is quite straightforward,

Silvia Ma Lu

How the team tested rose-tinted, semi-transparent panels

Ma Lu and colleagues mounted commercially available magenta glazing with embedded cadmium telluride (CdTe) strips over three 20-square-meter plots planted with broccoli. One plot was left in full sun as the control; the other two sat beneath magenta panels set to 50 percent and 70 percent transparency. The magenta glass transmits red and blue wavelengths while filtering green light; the CdTe strips harvest energy where they sit on the panel glass.

Using three matched plots allowed the authors to compare plant development and the panels' electricity output over the same growing period. The paper, published in Cell Reports Physical Science, reports the experimental layout and the choice of broccoli because it is a cultivar of Brassica oleracea, the species that also includes cabbage, cauliflower, kale, Brussels sprouts and kohlrabi. The team notes the magenta glazing was originally intended for building design and was repurposed here because it was commercially available for prototype testing.

Plant responses: yields matched but crops took longer

Across the two magenta configurations the broccoli produced similar harvested mass to the full-sun control, yet development was slower: plants under the magenta panels took 25 days longer to reach harvest. The researchers interpret that as greater efficiency in how the plants used available light: despite receiving less total light, they produced comparable yield.

The paper quantifies the shift in how plants used light: under panels with 50% transparency light-use efficiency increased by a factor of 4.5, while under the 70% panels it rose by 2.8. The authors say directing more red and blue light (and less green) can change how crops allocate energy, but they caution the findings reflect this specific experiment and need testing across more seasons and crop types.

Electricity produced and the economic trade-offs

Across the season the magenta panels delivered roughly 224.7 MWh per hectare, which the authors report is about 100 MWh per hectare less than conventional panels of similar footprint. Ramesh Rayudu, a power-systems engineer who was not involved in the work, translated that gap into economic terms: depending on electricity prices and the value of broccoli, the reduced generation would need approximately 1.2 to 3.2 tonnes of additional broccoli per hectare to offset the shortfall.

That arithmetic highlights the central trade-off for agrivoltaic designs that alter spectral availability: land and spectrum allocated to crops can raise agricultural value per square metre, but any reduction in energy output must be remunerated through higher crop value or other co-benefits. The experiment does not yet separate how much of the crop response comes from the magenta filter itself versus the overall reduction in light level, nor does it quantify the panels' commercial electricity yield by transparency level.

Where rose-tinted panels might fit and the remaining unknowns

Ma Lu suggests configurations similar to the prototype may suit smaller-scale applications, saying they could be suitable for community gardens or integration into greenhouse roofs rather than immediate deployment over large agricultural areas. That positioning follows from the panels being commercially available glazing for buildings; their use over large fields would require engineering refinements to recover green-spectrum energy and to manage microclimate effects beneath glass.

The study flags several gaps before scale-up: the current magenta glass blocks green light that the CdTe strips do not capture; the experiment did not quantify the greenhouse effect created by overlaying glass; and tests ran for a single season and a single crop. The authors and outside experts therefore call for multi-season trials, targeted cell designs that harvest a broader spectral band, and real-world greenhouse pilots to measure temperature, humidity and pest interactions under the panels.

Arguments for and against near-term uptake

The bottom line

The trial by Silvia Ma Lu’s team shows a practical proof of concept: commercially available rose-tinted glazing, combined with strips of CdTe solar cell, can pass the red and blue wavelengths crops need while producing measurable electricity—about 224.7 MWh per hectare in this experiment—without reducing harvested broccoli mass. The results frame a familiar agrivoltaic trade-off: slower crop development (25 days longer here) and lower electricity versus the benefit of co-locating food and power. Before any large-scale rollout, engineers must close the roughly 100 MWh/ha generation gap, test designs that harvest blocked green light, and validate outcomes across seasons, crops and greenhouse conditions.

What to watch

• Watch for multi-season field trials that replicate these 20-square-meter experiments; no date has been set.
• Watch for greenhouse-roof pilot projects using magenta glazing to report microclimate data; no date has been set.
• Watch for engineering papers or patents testing wavelength-selective cells that harvest green-spectrum light; no date has been set.