Results in Engineering (Dec 2024)
Design, development and experimental evaluation of a concentrator agrivoltaic system with integrated spectrally splitting Fresnel lens
Abstract
The main aim of this research is to develop and evaluate a cost-effective, innovative agrivoltaic system that optimizes land use by simultaneously producing agricultural products and generating electricity on the same land. In this regard, a highly transparent concentrator agrivoltaic system that utilizes the spectral splitting property is developed. The system consists of a Fresnel lens coated with a dichroic thin film and a receiver made of silicon solar cells. In this system, the sunlight is first focused by a Fresnel lens and then split into two spectral ranges by the dichroic film: (i) photosynthetically active radiation (PAR), which passes through the film and can be utilized by the plants, and (ii) the remaining spectrum, which is reflected to the receiver to generate electricity. Cherry tomatoes and mint were planted under the system. The results showed that the receiver reduces the intensity of the focused radiation by almost 3.28 times. The optical efficiency of the receiver is 83.1 % and the electricity generated is up to 18.1 W. The photosynthetic photon flux density (PPFD) under the agrivoltaic system ranges from 229 to 778 μmol/m2 s, while the daily light integral (DLI) varies between 13.5 and 27 mol/m2.d. Cherry tomatoes grown in the shade of the agrivoltaic system are larger, heavier and have a deeper red hue, while the mint plants have larger, greener, and longer leaves. In addition, the agrivoltaic system provides cooler soil temperatures, ranging from 3.66 °C to 9.53 °C, and retains 5.7 %–8.4 % more moisture, resulting in less water consumption. The total initial cost of the system was USD 587 and included the agricultural and photovoltaic components and maintenance. Over a period of ten years, the cumulative costs are likely to amount to USD 1165. However, the system has strong economic potential, starting at an annual income of USD 27 and expected to exceed USD 15,000. This analysis indicates a favorable return on investment that should pay for itself within six years.
