How can we help you today?
Agrivoltaics: Renewable energy and food combined
Wednesday, September 9, 2020
Ground Mount Systems
Most of us are aware of the large scale ground mount systems that are popping up not only in Australia but other countries with high solar irradiance. In many cases these solar ‘farms’ are on perfectly arable land and some in the community have expressed concerns about a potential displacement away from traditional agricultural pursuits.
An idea to combat these fears is the concept of agrivoltaics. According to Wikipedia, https://en.wikipedia.org/wiki/Agrivoltaic this technique was originally conceived by Adolf Goetzberger and Armin Zastrow in 1981.
Effectively it is the utilisation of the space between and under the PV array and relates to growing forage crops and/or allowing livestock to graze. The standard design of these solar farms is altered slightly whereby the panels are raised to a higher level to allow more light to reach under the panels and to alleviate issues with stock using the panels as scratching posts.
Energy Management: Mixed Use Land Proposition
So what we are talking about is a mixed use land proposition where farmers are potentially paid rental income from the owners of these ground mount systems but can still utilise arable land. In this situation, they can also take advantage of the increased soil moisture levels and created micro climates that by default have been created by the shading effects of the installed PV system.
“Experienced PV installer Ben Wynn has for years been planning how to bring together agricultural solar power projects” see article https://www.pv-magazine.com/2019/10/14/australian-agrivoltaics-start-up-aiming-for-eventual-1-gw-of-solar-capacity/
These financial arrangements can include a straight leasing arrangement or a leasing community shares arrangement and for the farmers, accessing a steady reliable income stream from these solar farms gives them a buffer against droughts, floods and all the other variables encountered when dealing with crops and/or livestock.
Benefits of solar
There have also been unexpected additional benefits reported such as decreases in lamb deaths from predator bird attacks. Other positive effects include lower ambient temperatures around the actual panels due to transpiration from the grasses and crops grown under or near the array which has led to increased solar energy production.
“A study, conducted on “unirrigated pasture that often experiences water stress” at Rabbit Hill agrivoltaic solar farm on the Oregon State University campus, reported a 328% increase in the water efficiency of soils under partial solar panel shading and wind protection. Those more favorable conditions contributed to a 90% increase in biomass growth under the panels” (https://ir.library.oregonstate.edu/)
A lot of the issues around the actual sites of these solar farms include the distances to nearest towns and who will be consuming the energy produced. This coupled with the fact that the cheaper the land, the less arable it is but the further away it is, in most cases, from sizable townships. A fair proportion of arable land is fairly close to cities where the produce via the relevant supply chains can easily access viable markets.
Cost benefit analysis
The farmer with substantial land holdings must of course do a cost benefit analysis. One approach is to calculate the exact value of each metre squared of land based on crop/livestock potential alone and then weigh that against the advantages of a steady income stream from the solar farm owners albeit with a reduced canvas on which to grow crops and/or hold livestock. In addition the farmer may have large electrical loads of his own so a smaller ground mount system to address the consumption of the site may also make it a viable option.
Agrivoltaics really addresses the whole sustainability factor when it comes to improved, intelligent land use. Pastures can now be viewed as total energy providers with the ability to generate electricity, grow and nurture forage crops as well as provide grazing pastures and areas of shade and safety for livestock. A win win situation!