Tag Archive for: Farm Energy Efficiency

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.

This North Dakota State University Extension publication provides an introductory checklist of energy efficiency opportunities for greenhouses. The checklist includes air leaks, double covering, energy conserving curtain, foundation and sidewall insulation as well as space utilization.

This North Dakota State University Extension publication provides energy efficiency information for grain drying. The checklist includes an overview of grain-drying energy, facts and actions on grain drying and additional resources for grain dryers.

This North Dakota State University Extension publication provides an introductory overview of energy auditing for a farmstead. The checklist includes tractor and field operation(s), details regarding grain drying practices, indoor and outdoor lighting and irrigation.

This Wisconsin Extension publication concerns energy conservation as a result of heat recovery in continuous flow column dryers. The publication includes details on heat recovery and cooling options for continuous flow dryers.

This NCAT ATTRA publication briefly discusses some of the considerations and potential benefits involved in the use of animal power and offers resources for further information and equipment. The publication includes an overview of uses and power potential for horses, mules, oxen and add-a-unit flexibility as well as considerations for safety and suitability and scarcity of knowledge and equipment.

This NCAT ATTRA publication provides an overview of how dairy farms can implement efficiency improvements and energy-saving technologies that can reduce energy consumption and energy-related costs. The publication includes details on the milking process, milk cooling systems, heating water and lighting.

This North Dakota State University Extension article concerns energy efficiency opportunities in tractors and field operations. The checklist includes a list of questions to ask related to proper tire inflation, RPM speed on larger tractors and shading for fuel storage. The document also includes a list of facts and actions regarding tractor maintenance, machine cost calculator and wheel slippage.

This NCAT ATTRA publication describes how to fi nd the net water application rate for any irrigation system. It further explains how to calculate the number of hours the system should be operated, describes several ways to measure flowing water in an open channel or pipeline, and offers suggestions for irrigating with limited water supplies.

This NCAT ATTRA publication explains how to maintain irrigation pumps, motors, and engines for peak efficiency. The publication includes descriptions and diagrams of recommended installations, checklists for maintenance tasks, and a troubleshooting guide. Each system component is treated separately and maintenance tasks are broken down by how frequently they need to be done.