Agrivoltaics: power and protection in the orchardResearch & Extension
This article was written by Rajandeep Singh, Research Scientist, Agriculture Victoria, and was first published in AFG Autumn 2022.
Could solar panels serve a dual purpose of generating energy while protecting the crop? AgVic scientists are putting them to the test.
Agrivoltaic research is a new field of study investigating the concurrent use of land for energy and crop production. While early studies examined the use of solar panels over vegetable crops, researchers at the Tatura SmartFarm, in Victoria’s Goulburn Valley, have designed innovative configurations to test solar panels over a high-density pear orchard.
The three-year Orchard Agrivoltaics project, begun in 2020, is funded under the Victorian Government’s Agriculture Energy Investment Plan (AEIP). The AEIP program endeavours to minimise on-farm energy consumption cost, lower emissions and build a more energy efficient agricultural sector.
The replicated orchard agrivoltaics experiment has been set up in a blush pear (‘ANP-0118’, marketed as Lanya™) orchard block with three treatments:
- 45° west-facing solar panels positioned to shade the canopy in the afternoon
- 5° west-facing solar panels positioned to shade the canopy at midday
- Control with no solar panels.
In total, 120 solar panels were mounted above the trees, at the height of 3.5m, using sturdy aluminium structures. Energy produced by the solar panels is stored in batteries, located in a nearby pump shed. The stored energy is used to run an irrigation pump and excess energy is fed to the grid. Three smart inverters with a combined capacity of 60kW regulate the energy production, storage and consumption and store all pertinent data. Stored data can easily be accessed through the online platform iSolarCloud, allowing real-time monitoring of energy production and consumption.
The agrivoltaics solar system is estimated to produce 58MWh in a year and it generated more than 22.5MWh overall energy during the summer months from November to January. Each configuration outperformed the other at different times of the year; however, the 5° west configuration generated approximately 3.4 per cent more daily energy than the 45° west for the period May 2021 to January 2022 (Fig 2).
Figure 2: Average daily energy produced by the 45° west (45W) and the 5° west (5W) solar panel configurations in the orchard agrivoltaics experiment at the Tatura SmartFarm.
Scientists at the Tatura SmartFarm are very keen to understand the effects of the solar panels on both sun damage and on the development of fruit colour throughout the season. For blush pears, development of blush with an attractive red colour is essential for premium grade fruit.
Lanya™ requires sunlight exposure to develop and maintain the blush colour, but too much exposure to sunlight can lead to sunburn of the fruit with severe cases leading to necrosis.
Visual sunburn assessment was performed on all fruit at harvest using a scale of 1 to 4, where 1 represents mild sunburn and 4 represents severe sunburn. In control plots more than 3 per cent of fruit was sunburnt, whereas in 45° west and 5° west treatments 0.2 per cent and 0.4 per cent of fruit were affected, respectively, indicating that solar panels can be effective in diminishing sunburn damage.