Impacts of Photovoltaic Solar Energy on Soil Carbon: A Global Systematic Review and Framework

Abstract

Solar energy is anticipated to be the primary energy source globally as early as 2050,
and the greatest additions in capacity are currently in the form of large, ground-mounted
photovoltaic solar energy facilities (GPVs). Growing interest lies in understanding and
anticipating opportunities to increase soil carbon sequestration across the footprint and
perimeter of both conventional and dual-use GPVs (e.g., ecovoltaics, agrivoltaics, and
rangevolatics), especially as operators increasingly deputize as land managers. Unfortunately,
studies on the relationship between soils and PV solar energy are limited to unique, localized
study sites. Here, we employed a systematic review to (i) identify a global corpus of 18 studies
on interactions between GPVs and soils, (ii) collect and characterize 113 soil and soil-related
experimental variables interacting with GPVs from this corpus, and (iii) synthesize trends among
these experimental variables. Next, we combined data from the systematic review with an
iterative, knowledge co-production approach to produce (1) a conceptual model of soil and GPV
interactions that applies to multiple installation types, scales, and contexts where GPVs are
deployed; and, (2) research opportunities, threats, and priorities. This study confers unique
insight into the feasibility of combining soil carbon sequestration with the climate change
mitigation potential of PV solar energy.

Keywords: carbon sequestration, climate change mitigation, greenhouse gases, renewable energy, photovoltaic solar energy, agrivoltaics, ecovoltaics, rangevoltaics, soil health, soil carbon, landscape restoration, solar farm, systematic literature review, causal loop diagram, land management, techno-ecological