New Solar Glass Cranks Up Lettuce Crop Yields By Almost 40%

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Despite the abrupt U-turn in federal energy policy, the march of American innovation carries on. In the latest example, the US startup UbiQD has developed a new form of solar glass that can help boost productivity in greenhouses. If adopted into widespread commercial use, the new glass has significant implications for the growth of climate-smart agricultural practices, including the emerging vertical farm industry as well as conventional greenhouse farming.

“UbiGro” Solar Glass & The Quantum Dot Solution

The new solar glass was field tested by researchers at the University of California – Davis, who published their findings in the journal Materials Today Sustainability in September under the title, “Spectrally selective quantum dot laminated glass for photonic modulation and climate regulation in greenhouses.”

If you’re wondering what a quantum dot is, that’s a good question. Also called “artificial atoms” and the “linchpins of new lighting technology,” quantum dots initially appeared on the pages of CleanTechnica for their application to LED lighting and active photovoltaic systems.

“Quantum dots are vanishingly small (nano) particles of semiconductor material that are highly effective at manipulating color and light,” UbiQD helpfully explains. “QDs can have remarkably high efficiency photoluminescence properties (they glow bright) over a wide-range of visible and invisible colors, tailored by adjusting their size and composition.”

As UbiQD notes, the UC-Davis study is the first to assess the performance of quantum dots integrated with passive solar glass. “These results prove that the sun can be engineered passively through QD-infused glass to deliver more productive, resilient, and sustainable food systems,” explains UbiQD CEO Hunter McDaniel, PhD.

New Quantum Dot Solar Glass By The Numbers

If the performance of lettuce is a bellwether for other crops, UbiQD’s solar glass passed the test with flying colors. The UC-Davis team reported a long list of enhancements compared to the control crop. Over a full winter growth period, the lettuce grown under UbiGro glass earned the following credits:

— Fresh biomass increased by 37.8%. Plants were nearly 40% heavier, indicating significantly more edible yield.

— Leaf area was increased by 38.0%. Larger leaf area means higher photosynthetic surface.

— Root length increased by 38.0%. Deeper roots improve water and nutrient uptake, resilience, and shelf life.

— Light-use efficiency was increased by 41.0%. The plants used sunlight more effectively, with more biomass per photon.

— Nutrient concentrations (N, P, K, Mg, Zn, Cu) were significantly elevated. The crops were more nutritious, with higher levels of essential nutrients.

— Spectral red:blue ratio increased by 61.0%, with no significant PAR losses. More red light was delivered without sacrificing total usable light levels.

“These results underscore the potential of spectrally selective QD-glazing as a passive, energy-free solution for optimizing greenhouse microclimate and supporting resilient, winter-season crop production,” the researchers concluded.

“The findings highlight a promising pathway toward climate-smart greenhouse envelopes that integrate photonics with sustainable food and energy strategies,” they added for good measure.

From Solar Glass To Solar Cells

UbiQD is not letting the grass grow under its feet. Eric Moody, the firm’s VP of Sales and Marketing, already anticipates commercial scale-up. “Our film products are already delivering strong results in commercial greenhouses around the world, and this new data supports our broader vision for integrating light-optimizing technologies — like our upcoming glass innovations — into agriculture at scale,” Moody said.

In addition to the solar glass venture, UBiQD is also applying its quantum dot technology to the thin film solar cell field, through a supply agreement with the US firm First Solar. The two firms announced the agreement in July. “This collaboration between two U.S.-based companies comes as the country seeks to rapidly expand competitive power generation capacity to serve demand from data centers, artificial intelligence (AI), and manufacturing,” UbiQD noted in a press statement.

First Solar is applying the technology to its bifacial solar modules, which also has some interesting implications for sustainable agriculture. Bifacial solar modules harvest solar energy through their backs as well as their fronts. Unlike conventional solar panels that must be situated at an angle for maximum efficiency, bifacial solar panels can be parked in an upright position, enabling them to serve as fencing and other farm infrastructure in the field of agrivoltaics.

More Solar Energy For The USA

Keep an eye on bifacial solar technology to pop up in non-farm uses as well. The US branch of the German firm Next2Sun, for example, has lent its bifacial solar panels to an agrivoltaic project in Vermont, and it is also among the growing number of US companies to offer bifacial solar panels as a sleek, stylish alternative to plastic privacy fences for residential use.

“Fence2Sun, the Next2Sun solar fence for private households is not only able to generate enough electricity to cover the needs of a single-family household, but also offers a low-maintenance and weather-resistant replacement for hedges and fences,” Next2Sun explains. Solar fences can also provide a workaround for properties where opportunities for rooftop solar are limited by shade, by the condition of the roof, or by the size of the roof.

Solar Glass Is Coming For Your Fossil Fuels

The field of transparent solar cells is yet another angle on the solar glass field. With transparent solar technology, glass-clad buildings could pull double duty as power stations while enabling daylight through to interior spaces (see more transparent solar background here).

That sounds simple enough, but the devil is in the details. Transparent solar glass has surfaced on CleanTechnica for 15 years with little to show in terms of commercial applications. However, signs of a breakthrough are beginning to emerge.

Keep an eye on the California firm NEXT Energy Technologies. In July, the company reported that it has installed a commercial-level solar glass facade at its headquarters in Santa Barbara. The installation consists of six panels for a total of 100 square feet. That’s not a particularly dramatic size, but the installation is significant because it demonstrates the first use of building-integrated solar technology to deploy the firm’s organic photovoltaic coatings.

“Visitors can see the seamless integration of solar technology into a standard commercial facade and observe firsthand how the system generates power while maintaining transparency and design flexibility, NEXT explains.