The orange-tinted solar panels could be utilized in the future, allowing farmers to generate electricity while producing vegetables. (Image Credit: University of Cambridge)
In the future, farmers could grow their crops indoors underneath tinted semi-transparent solar panels, allowing them to generate electricity while growing vegetables. This is what researchers at the University of Cambridge have already achieved, and they say it could result in larger profits for farmers and maximize agricultural land use.
Using semi-transparent solar panels to produce both electricity and crops at the same time has been done before through a technique called ‘agrivoltaics.’ The cells and modules are usually spaced apart, which allows sunlight to reach the crops. However, it’s impossible to prevent shadows of opaque modules from landing on the crops, causing a reduction in biomass growth.
This new study shows that utilizing semi-transparent modules could yield better results. The thin-film amorphous silicon modules have a transparent zinc oxide back conductive layer and clear front glass coated with fluorine tin oxide. The photovoltaic section of the panels is laminated between two sheets of glass. These panels prompt 8% conversion efficiency and have an output of 66 W m−2.
The panels are capable of filtering out different wavelengths of light, depending on their color. The team used orange-tinted panels to absorb blue and green wavelengths while only allowing red light to shine on the plants since it’s more beneficial for them.
The researchers observed how growing spinach and basil under the orange-tinted panels work. In this experiment, the team grew the plants in a conventional greenhouse and under semi-transparent solar panels. Afterward, they compared their findings.
With less light passing through, the crops went through some morphological changes. The team discovered there was a reduction in biomass, which includes a 15% and 26% reduction of leaves the basil and spinach produced, respectively. This could cut into farmer’s profits. When factoring in power generated by the panels, which could be sold to the grid or used to offset energy use elsewhere, the crops resulted in a financial gain of 2.5% for basil and 35% for spinach.
Interest in this new technology has increased over the past few years. Now that the climate crisis has gained more attention with increased urgency, engineers have been attempting to come up with solutions for future land use. Instead of having a future where energy and crops compete for land space, these solar panels could allow them to share space. However, this technology has some limitations. The spinach and basil roots had the most considerable reduction in size compared to other parts of the plants. This means this growing and power generating technique wouldn’t be ideal for root vegetables such as potatoes, beets and carrots.
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