Strawberry fields forever, and with transparent PV
Scientists have grown strawberries under thin-film cadmium telluride panels with varying transparency. They found that 40% transparency maintained a greater than 80% yield of uncovered plants. If all strawberry farms in the world were converted to agrivoltaics, they would produce up to 173 TWh a year.
Scientists have grown strawberries under thin-film cadmium telluride panels with varying transparency. They found that 40% transparency maintained a greater than 80% yield of uncovered plants. If all strawberry farms in the world were converted to agrivoltaics, they would produce up to 173 TWh a year.
Researchers from Canada’s Western University have tested the growth of Delizz Strawberries under PV panels with varying levels of transparency.
They constructed a replica of the outdoor conditions of London, Ontario, and then measured the fresh weight of the strawberries, plant height, leaf count, and flower count. Furthermore, they have also calculated the amount of electricity strawberry agrivoltaics can produce in Canada and worldwide.
“The goal of this study was to assess the impact of varying PV transparency on strawberry yield and growth under thin-film cadmium telluride (Cd- Te) modules and to evaluate the potential of agrivoltaics as a sustainable solution for strawberry production in northern climates,” corresponding author, Uzair Jamil, told pv magazine. “Notably, this is the first strawberry agrivoltaic study estimating strawberry yields under northern climates using Cd-Te PV modules.”
The controlled room the team designed consisted of 16 hours of daylight and 8 hours of darkness cycle. Daytime temperatures were maintained at 25 C, while nighttime temperatures were kept at 19 C, reflecting the average summer climate in London from May to August. Four 600 W high-pressure sodium (HPS) lamps were used to improve natural illumination.
All PV panels had the same measurements: a length of 1,200 mm, width of 600 mm, and thickness of 7 mm. They differed in their transparency level and, therefore, in their maximum rated power. The panel with 10% had a power of 72 W, the 30% transparency had 56 W, and the 40% had 58 W. Panels with transparencies of 50%, 60%, 70%, and 80% had a nominal maximum power of 40 W, 32 W, 24 W, and 16 W, respectively.
“Six replicates of strawberry plants were cultivated under each module, while eight replicates were grown without modules to serve as controls, all planted in 3.8 L pots,” the group explained. “Both the experimental and control groups were housed within the same biome. The growing medium for all plants was ProMix BX soil.”
Image: Western University, Solar Energy, CC BY 4.0
The experiment started on February 20, 2024; data was collected across 112 days. Per the results, the average fresh weight of the control strawberries was up to 50.8 g. The 10% transparency module had underneath a fresh weight of up to 9.5 g, the 30% had 15 g, the 40% had 25.5 g, the 50% had 20 g, the 60% performed with 19.5 g, the 70% with 51.7 g and the 80% transparency had an average fresh weight of 30.7 g.
“The results indicate that strawberries grown under 70% transparency PV modules exhibited a fresh weight 140.6% of the average control,” the group said. “Additionally, yields exceeding 80% of the control were observed with 40%, 50%, and 80% transparent PV modules, which makes their deployment legal for areas that have agrivoltaics policy based on maintaining a greater than 80% yield. “
Based on their data, the academics conducted a statistical analysis that proved that the transparency rate impacts the growth yield. This analysis found a strong positive correlation between the measured photosynthetically active radiation (PAR) and strawberry fresh weight, with Pearson’s correlation coefficient (r) of 0.693. PAR represents the portion of light that plants use for photosynthesis.
In addition, the researchers used their results and the system advisor model (SAM) software to estimate the electricity generation potential of strawberry agrivoltaics farms in Canada and globally. They found that the Canadian potential ranges between 595 GWh and 1,786 GWh annually, depending on the transparency level of the modules. That will result in a CO2 emission reduction of 65 kilotons (kt) to 196 kt annually. On a global scale, the electricity potential of strawberry fields ranges between 58 TWh and 173 TWh, and the CO2 reduction is between 27 Mt and 82 Mt annually.
“The adoption of agrivoltaics in the Canadian strawberry sector could facilitate energy self-sufficiency and transform it into a net electricity exporter, generating additional revenue for farmers,” the team concluded. “These findings highlight the substantial benefits of agrivoltaics, including enhanced agricultural productivity, significant clean energy generation, increased farmer income, and lower food prices.”
Their findings were presented in “Experimental impacts of transparency on strawberry agrivoltaics using thin film photovoltaic modules under low light conditions,” published in Solar Energy.
What's Your Reaction?
