Herbage Yield, Lamb Growth and Foraging Behavior in Agrivoltaic Production System

Abstract

Agrivoltaic systems are designed to mutually benefit solar energy and agricultural production in the same location for dual-use of land. This study was conducted to compare lamb growth and pasture production from solar pastures in agrivoltaic systems and traditional open pastures over 2 years in Oregon. Weaned Polypay lambs grew at 120 and 119 g head−1 d−1 in solar and open pastures, respectively in spring 2019 (P = 0.90). The liveweight production between solar (1.5 kg ha−1 d−1) and open pastures (1.3 kg ha−1 d−1) were comparable (P = 0.67). Similarly, lamb liveweight gains and liveweight productions were comparable in both solar (89 g head−1 d−1; 4.6 kg ha−1 d−1) and open (92 g head−1 d−1; 5.0 kg ha−1 d−1) pastures (all P > 0.05) in 2020. The daily water consumption of the lambs in spring 2019 were similar during early spring, but lambs in open pastures consumed 0.72 L head−1 d−1 more water than those grazed under solar panels in the late spring period (P < 0.01). No difference was observed in water intake of the lambs in spring 2020 (P = 0.42). Over the entire period, solar pastures produced 38% lower herbage than open pastures due to low pasture density in fully shaded areas under solar panels. The results from our grazing study indicated that lower herbage mass available in solar pastures was offset by higher forage quality, resulting in similar spring lamb production to open pastures. Our findings also suggest that the land productivity could be greatly increased through combining sheep grazing and solar energy production on the same land in agrivoltaics systems.

Solar Photovoltaic Architecture and Agronomic Management in Agrivoltaic System: A Review

“…These conflicts are compounded by the fact that the amount of arable land available per capita decreased by 48 percent between 1961 and 2016, owing to the global population increase [41]. Thus, it is believed that the solution of AVS technologies enables the possibility of resolving the competing interest between the two sectors' requirements while meeting the demand [14,21,[42][43][44].…”

“…A setup by Refs. [42,134] in particular divided the area beneath the solar panel into three subtreatments: (1) sky fully open area between panels (SFO); (2) Solar partially open between panels (SPO); (3) solar fully covered area under panels (SFC) as illustrated in Figure 3A. SFO zones are located between the edges of mounted photovoltaic panels and areas that have received full light [28].…”

“…For the location of sub-treatments which are SFO, SPO and SFC [42,132], or FD and HD [4,6,18,69], a wide range of crops can be selected to be planted based on their physiological and morphological traits [4,28,71]. Besides that, the selection of suitable crops for AVS should also be identified based on local climate and weather conditions [5,12,21,28].…”

Agrivoltaics in Ontario Canada: Promise and Policy

“…There have been some notable demonstrations, such as Arnprior's tri-part agrivoltaic system that houses a monarch butterfly conservation project, a bee/honey project, and a solar grazing/natural weed abatement pilot project [66]. Most Canadian agrivoltaics are primarily using conventional solar farms for grazing sheep, which does have positive benefits for both the sheep (i.e., protection [67] and higher quality grazing areas [68]), but also the PV systems (i.e., less labour for mowing) and the environment [69]. These lower-tier uses of agrivoltaics, however, leave out the majority of the potential agrivoltaic benefits.…”

Agrivoltaics in Ontario Canada: Promise and Policy

“…Most Canadian agrivoltaics are primarily using conventional solar farms for grazing sheep, which does have positive benefits for both the sheep (i.e. protection [67] and higher quality grazing areas [68]), but also the PV systems (i.e. less labor for mowing) and the environment [69].…”