Vegetation Management Cost and Maintenance Implications of Different Ground Covers at Utility-Scale Solar Sites

Abstract

Utility-scale solar photovoltaics (PV) is the largest and fastest-growing sector of the solar energy market, and plays an important role in ensuring that state and local jurisdictions can meet renewable energy targets. Potential adverse environmental impacts of utility-scale solar PV are well-documented, and the effects of diverse mitigation and dual land use strategies under the banner of 'low-impact solar' are justly receiving more attention; this article seeks to contribute to improving understanding of this topic. Capital costs for different PV configurations are well-documented; however, operation and maintenance (O&M) costs for vegetation management at low-impact utility-scale solar PV sites are not as well-understood, particularly as they compare to costs for sites that use more conventional ground cover practices, such as turfgrass or gravel. After a literature review of different vegetation strategies and O&M cost considerations, we collected data from utility-scale solar PV O&M stakeholders, including site owners/operators, O&M service providers, vegetation maintenance companies, and solar graziers, on costs and activities associated with vegetation management at low-impact, agrivoltaic, and conventional PV sites. In this paper, we perform data analysis to detail the per-activity and total O&M costs for vegetation management at PV sites with different ground covers and management practices, providing the most comprehensive and detailed assessment of PV vegetation O&M costs to date. For the 54 sites included in our analysis, we found that while the per-acre and per-kilowattdc (kWdc) costs for individual activities, such as mowing, trimming, and herbicide application at native or pollinator friendly ground covers, were lower than at turfgrass sites, the total combined vegetation O&M costs were slightly higher; this is presumably because more individual activities are required for the first 3–5 years of vegetation establishment. Qualitative results include recommendations from data providers for site and system design, and ongoing vegetation management operations.

Photovoltaic + Photosynthetic Coexistence: Towards a Sensible Accelerated Mass Integration of PV Onto a Perturbed Planet

“…For such seeding, there has unfortunately (until recently) seemed to be little incentive to spend more capital than on the absolute cheapest grass species, or even gravel, if permitted by local authorities. (McCall et al, 2023).…”

“…Studies and experiences have shown that such techniques as planting native groundcover species (though often a higher initial cost than turfgrass or gravel) can decrease long-term O&M expenditures on vegetation and soil erosion management (McCall et al, 2023). Some of these native species that show long-term stability are flowering plants, which have been shown to boost pollinator populations, leading to the coining of the term "pollinator-friendly solar" in the US.…”

“…The term "low impact solar" should also be noted, as having arisen along with this genesis of proto ecovoltaics in the United States to loosely describe a variety of vegetation management, animal grazing, and civil engineering practices to reduce environmental impacts on PV projects, though the term's correlation with crop agrivoltaics remains unclear, due to the latter's small sample size in the US (McCall et al, 2023).…”

Little prairie under the panel: testing native pollinator habitat seed mix establishment at three utility-scale solar sites in Minnesota

“…Establishing pollinator habitat at solar sites has been referred to as both agrivoltaics and ecovoltaics in current literature, but agrivoltaics can include other land uses such as animal grazing and crop production [9,10]. Pollinator habitat at solar facilities may also directly contribute to agriculture production through honey production from apiaries located on site [11].…”

From Fields to Photovoltaics: Effects of Agrisolar Co-Location on Food, Energy, Water, and Economic Security

“…In agricultural settings, crop production and solar PV can be laterally integrated (agrisolar colocation) 19 , and/or directly share land and photons via vertical integration (agrivoltaic colocation) 20,21 .Effective agrivoltaic management can improve agricultural yield, microclimate regulation, soil moisture retention, nutrient cycling 12,[22][23][24][25][26] , and farmer profitability 24,27,28 , while reducing public opposition 29,30 . Aside from installation and management costs concerns [31][32][33] , agrivoltaics have few net-negative consequences 12,21,[34][35][36] . However, techno-economic and political challenges remain for broad deployment of this practice 35,[37][38][39] .…”