A slide presentation by Ku Leuven focusing on suitable sites for agrivoltaics in a pear orchard.
Tag Archive for: solar farming
Developing methods for the sustainable coproduction of food, energy and water resources has recently been recognized as a potentially attractive solution to meeting the needs of a growing population. However, many studies have used models, but have not performed an actual experiment to directly validate all their predictions. Here, we report a recently-constructed test site on the ACRE farm in West Lafayette, Indiana, consisting of single-axis trackers in a novel configuration atop a maize test plot. We present a methodology to measure irradiance therein with 10-minute temporal resolution, which allows us to validate prior PV aglectric farm irradiance models. In spring 2019, an experimental aglectric system was constructed at the Purdue University Agronomy Center for Research and Education (ACRE) farm. This experiment, commonly referred to as the ACRE Solar Array, comprises of 4 single-axis solar trackers implemented in east-west tracking mode. The solar trackers are raised 20 ft above ground level and welded to steel I-beams for compatibility with current high-yield agricultural practices such as mechanized farming. This work modifies and leverages a previously developed ray-tracing model that calculates irradiance reaching the ground. Using the open-source library PVLib, spatial maps of intensity variation are calculated for direct and diffuse light. Solar input was based on astronomical data calculated in PVLib and historical weather data from West Lafayette. The percentage reduction in irradiance for a simulated structure in comparison with an open field is calculated and referred to as shadow depth (SD). The model is capable of simplistic systems as well as custom array layouts such as the ACRE Solar Array. A methodology for validation of spatial and temporal irradiance maps of non-uniform shadow distributions has been evaluated and shows significant agreement.
Plant pest spraying machines are now starting to develop using a variety of technologies ranging from diesel to electric power. However, this technology has problems such as limited fuel capacity in diesel engines and a lack of electricity demand for electric batteries. If the sprayed area is too large, the capacity for fuel and battery requirements is insufficient. In this study, we will explain how to apply solar cells to make a plant pest spraying machine so that when spraying will occur simultaneously the process of charging or charging the battery by solar power. So that the need for battery capacity is met for spraying over a large area. The process of making this tool is done by assembling several components such as solar panels, SCC (solar charge controller), spray tanks and lithium batteries.
In this paper, new models of solar light trap was proposed which will be the most effective IPM tool for the monitoring of insect pests and their monitoring of insect pests and their mechanical control in the field of agriculture, provide no harm to the nature and also have low cost involvement so that it can be utilized by most of the farmers. For that purpose firstly a model of light trap box with iron structure was developed, then a solar light system including solar panel, charging unity, battery and LED bulb installed with the light trap box so that this solar light trap can monitor and control the insect pests of different crops effectively. It is the most effective IPM tool which provide better safeguard to the nature in comparison to the other method of pest control.
Kale, chard, broccoli, peppers, tomatoes, and spinach were grown at various positions within partial shade of a solar photovoltaic array during the growing seasons from late March through August 2017 and 2018. The rows of panels were orientated north-south and tracked east to west during the daylight hours, creating three levels of shade for the plants: 7% of full sun, 55-65% of full sun, and 85% of full sun, as well as a full sun control outside the array. Average daily air temperature at canopy height was within +\- 0.5oC across the shade conditions. Over two field seasons, biomass accumulated in correction with the quantity of photosynthetically active radiation (PAR). Kale produced the same amount of harvestable biomass in all PAR levels between 55% and 85% of full sun. Chard yield was similar in PAR levels 85% and greater. Tomatoes produced the same amount harvestable biomass in all PAR levels greater than 55% of full sun. Broccoli produced significantly more harvestable head biomass at 85% than at full sun irradiance but required at least 85% of full PAR to produce appreciable harvestable material. Peppers generated harvestable fruit biomass at PAR of 55% of full sun or less, but yielded best at 85% of full sun or more. Spinach was sensitive to shade, yielded poorly under low PAR, but increased biomass production as PAR increased. Microclimate variations under PV arrays influence plant yields depending on location within a solar array. Adequate PAR and moderated temperature extremes can couple to produce crop yields in reduced PAR environments similar to and in some cases better than those in full sun. Results from our study showed that careful attention must be made when developing PV arrays over the crops and when choosing which crops to plant among the arrays.
As an answer to the increasing demand for photovoltaics as a key element in the energy transition strategy of many countries—which entails land use issues, as well as concerns regarding landscape transformation, biodiversity, ecosystems and human well-being—new approaches and market segments have emerged that consider integrated perspectives. Among these, agrivoltaics is emerging as very promising for allowing benefits in the food–energy (and water) nexus. Demonstrative projects are developing worldwide, and experience with varied design solutions suitable for the scale up to commercial scale is being gathered based primarily on efficiency considerations; nevertheless, it is unquestionable that with the increase in the size, from the demonstration to the commercial scale, attention has to be paid to ecological impacts associated to specific design choices, and namely to those related to landscape transformation issues. This study reviews and analyzes the technological and spatial design options that have become available to date implementing a rigorous, comprehensive analysis based on the most updated knowledge in the field, and proposes a thorough methodology based on design and performance parameters that enable us to define the main attributes of the system from a trans-disciplinary perspective. The energy and engineering design optimization, the development of new technologies and the correct selection of plant species adapted to the PV system are the areas where the current research is actively focusing in APV systems. Along with the continuous research progress, the success of several international experiences through pilot projects which implement new design solutions and use different PV technologies has triggered APV, and it has been met with great acceptance from the industry and interest from governments. It is in fact a significant potential contribution to meet climate challenges touching on food, energy, agriculture and rural policies. Moreover, it is understood—i.e., by energy developers—as a possible driver for the implementation of large-scale PV installations and building integrated agriculture, which without the APV function, would not be successful in the authorization process due to land use concerns. A sharp increase is expected in terms of number of installations and capacity in the near future. Along this trend, new concerns regarding landscape and urban transformation issues are emerging as the implementation of APV might be mainly focused on the efficiency of the PV system (more profitable than agriculture), with insufficient attention on the correct synergy between energy and food production. The study of ecosystem service trade-offs in the spatial planning and design for energy transition, to identify potential synergies and minimize trade-offs between renewable energy and other ecosystem services, has been already acknowledged as a key issue for avoiding conflicts between global and local perspectives. The development of new innovative systems (PV system technology) and components (photovoltaic devices technology) can enhance the energy performance of selected design options for APV greenhouse typology.
Worldwide, water is becoming scarcer and more expensive due to the effects of climate change. Significant adaptation will be necessary to ensure adequate supply and efficient use of a diminishing resource. This reduction in the supply of water will affect agriculture and will require a change in focus from increasing productivity of land to increasing productivity per unit of water consumed.
Solar photovoltaic (PV) technology is being deployed at an unprecedented rate. To this end, we investigated critical soil physical and chemical parameters at a revegetated photovoltaic array and an adjacent reference grassland in Colorado, United States.
This study, performed by a research group that includes AgriSolar Clearinghouse partners Greg-Barron Gafford and Jordan Macknick, describes an integrative approach for the investigation of the co-location of solar photovoltaics and crops, and the potential for co-located agrivoltaic crops in drylands as a solution for the food-energy-water nexus impacts from climate change.
The research focused on three common agricultural species that represent different adaptive niches for dryland environments: chiltepin pepper, jalapeño, and cherry tomato. The researchers created an agrivoltaic system by planting these species under a PV array—3.3m off the ground at the lowest end and at a tilt of 32°—to capture the physical and biological impacts of this approach. Throughout the average three-month summer growing season, researchers monitored incoming light levels, air temperature and relative humidity continuously using sensors mounted 2.5m above the soil surface, and soil surface temperature and moisture at 5-cm depth. Both the traditional planting area (control) and agrivoltaic system received equal irrigation rates, with two irrigation scenarios—daily irrigation and irrigation every 2ays.
The researchers found that shading from the PV panels can provide multiple additive and synergistic benefits, including reduced plant drought stress, greater food production and reduced PV panel heat stress. The agrivoltaic system conditions impacted every aspect of plant activity, though results and significance varied by species. The total fruit production was twice as great under the PV panels of the agrivoltaic system than in the traditional growing environment
Cumulative CO2 uptake was 65% greater in the agrivoltaic installation than in the traditional growing area. Water use efficiency was also 65% greater, indicating that water loss to transpiration was equal between the treatment areas. The increased productivity in the agrivoltaic system is probably due to an alleviation of multiple stress interactions from heat and atmospheric drought.
Because PV panels are sensitive to temperature, the cooling of panels below daytime temperatures of 30 °C positively impacts their efficiency. In this study, researchers found that the PV panels in a traditional ground-mounted array were significantly warmer during the day and experienced greater within-day variation than those over an agrivoltaic understory. Researchers attribute these lower daytime temperatures in the PV panels in the agrivoltaic system to a greater balance of latent heat energy exchange from plant transpiration relative to sensible heat exchange from radiation from bare soil. Across the core growing season, PV panels in an agrivoltaic system were ~8.9+0.2 °C cooler in daylight hours. This reduction in temperature can lead to an increase in PV system performance. Using the system advisor model (SAM) for a traditional and a colocation PV system in Tucson, AZ, researchers calculated that impact from temperature reductions from the agrivoltaic system would lead to a 3% increase in generation over summer months and a 1% increase in generation annually.
These results show the additive benefits of agrivoltaics, to both crop production and energy production, as well as the impacts to ecosystem services such as local climate regulation, water conservation, and drought resiliency.
The article concerns the performance of a solar water heater with gas backup and an air-source heat-pump water-heater at a dairy farm in Ireland. The publication discusses the heater’s affect on energy efficiency and it’s relation to renewable energy, emission and target interactions as identified in the document.
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