Agrivoltaics

Sep 17

Global energy demand is expected to double by 2050, and large-scale renewable energy “farms” are being deployed across the United States with increasing frequency to meet demands for clean energy generation and to reduce greenhouse gas emissions related to climate change. Solar energy (photovoltaic) farms, in particular, are often most easily sited on large parcels of flat land that are already in use for conventional monoculture farming, leading to land use conflicts between these two purposes for the same area of land. Efforts directed toward alleviating this tension have led to the development of various agrivoltaic production models—symbiotic co-location methods of growing food or providing ecosystem services under and around solar panel arrays. This article is intended to provide a brief overview of some of the discussion in this area so far.

Though initially somewhat promising, agrivoltaics is an emerging field of research and experimentation that does not yet benefit from decades of rigorous scientific data collection and study. This leaves many of the difficult questions on whether agrivoltaics can reasonably function effectively long-term unanswered. While still in its relative infancy, many civic leaders across the country are looking at the ideas contained in agrivoltaics when considering how to best proceed with siting, regulating, and permitting large-scale solar farms requested by corporate energy companies and their partners. Current research into co-location of agriculture and solar power generation have focused on livestock grazing, fruit and vegetable production, pollinator and honeybee production, annual row crop production, and native prairie rejuvenation and ecosystem services.

A few highlights of these methods include:

Rotationally grazing sheep for vegetation control at the solar site, providing fodder and increased income for farmers while decreasing maintenance costs for developers.

Specialty crops grown under solar panels can benefit from higher air and soil moisture and more balanced temperatures when compared to open field production. In studies performed by Arizona State University researchers, popular crops such as peppers and tomatoes had their yields increase by 150% and 80% respectively while reducing water use.

Developers can plant short varieties of perennial flowering plants and partner with beekeepers to keep honeybee hives at the solar site, improving habitat for honeybees and native pollinators.

Under the correct circumstances solar installations can allow for continued annual row crop production, though this requires further spacing of solar panel arrays to allow for agriculture equipment to manage crops. This may cause up to a 30% loss of yield, but more recent research at Purdue University achieved “near-zero crop yield losses” when solar was added to corn fields at ACRE Farm.

Some agrivoltaic projects have focused on using solar fields as protection areas for “rewilding” efforts in areas that previously had native prairie ecosystems. In neighboring developed areas, perennial vegetation has been shown to reduce peak stream flows by as much as 57% during flood events.

Allowing the incorporation of solar into farmland can provide additional income for landowners and taxes for the nearby communities and county at large. Solar leases in some areas can range up to $1,500/acre or more per year for the life of the solar array, creating an attractive financial incentive for farmers or landowners. Across the United States where expansion of renewable energy is being promoted, mitigating impacts to farmland and food production is a common goal. In their Agrisolar Policy Guide the Agrisolar Clearinghouse encourages large scale solar development policy to define what agrisolar legally means in that community’s context. Policy should include “…how inclusive or exclusive the definition is of the various types of co-location…the relevant electric utility, interconnection, system scale, community solar, net metering, farmer/landowner agreements, ownership models, and distinctions between on-farm and off-farm energy use.” Policy templates exist in the Agrisolar Policy Guide, which can be found here:

www.agrisolarclearinghouse.org/agrisolar-policy-guide/

Here at KRC, we want to champion both renewable energy and the preservation of local control and decision-making for communities across Kansas to protect their farmland and natural resources. Agrivoltaics is an interesting hybrid of agriculture and solar energy production that we’ll continue to watch closely as the research develops.

Ryan Goertzen-Regier - Program and Administrative Manager, KRC