Silver as a Constraint for a Large-Scale Development of Solar Photovoltaics? Scenario-Making to the Year 2050 Supported by Expert Engagement and Global Sensitivity Analysis

Samuele Lo Piano,Jeroen P Van Der Sluijs,Andrea Saltelli

doi:10.3389/fenrg.2019.00056

Samuele Lo Piano, Jeroen P Van Der Sluijs + Show 1 more

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https://doi.org/10.3389/fenrg.2019.00056

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Abstract

In this study we assess whether availability of silver could constrain a large-scale deployment of solar photovoltaics (PV). While silver-paste use in photovoltaics cell metallization is becoming more efficient, solar photovoltaics power capacity installation is growing at an exponential pace. Along photovoltaics, silver is also employed in an array of industrial and non-industrial applications. The trends of these uses are examined up to the year 2050. The technical coefficients for the expansion in photovoltaics power capacity and contraction in silver paste use have been assessed through an expert-consultation process. The trend of use in the non-PV sectors has been estimated through an ARIMA (auto-regressive integrated moving average) model. The yearly and cumulative silver demand are evaluated against the technological potential for increasing silver mining and the estimates of its global natural availability, respectively. The model implemented is tested with a quasi-random Monte Carlo variance-based global sensitivity analysis. The result of our inquiry is that silver may not represent a constraint for a very-large-scale deployment of photovoltaics (up to tens TW in installed power capacity) provided the present decreasing trend in the use of silver paste in the photovoltaics sector continues at an adequate pace. Silver use in non-photovoltaic sectors plays also a tangible influence on potential constraints. In terms of natural constraints, most of the uncertainty is dependent on the actual estimates of silver natural budget.

Highlights

Large-scale development of renewable energy is a conditio sine qua non for an energy transition away from fossil-fuel-based power sources
The trends for the yearly silver demand are presented in Figure 1A: the factors driving an increase of silver use are in most of the cases dominating the contribution over the factors driving a decrease
By analyzing the simulations that produce a feasible vs. a nonfeasible outcome, one can note that feasibility constraints will be practically certain to occur for a natural budget below 800 kton, likely between 800 and 1,100 kton (50% of the simulations), with no constraints beyond this threshold in any of the simulations. In this contribution we have assessed whether silver would represent a constraint for a large-scale development of solar photovoltaics for electricity production

Summary

Introduction

Large-scale development of renewable energy is a conditio sine qua non for an energy transition away from fossil-fuel-based power sources. We analyse whether silver may represent a constraint for the large-scale deployment of photovoltaic power capacity up to the year 2050 This potential criticality applies to other renewableenergy-based technology that resort to scarce metals for the manufacturing of the energy-harvesting devices. Grandell and Thorenz (2014) focused their analysis exclusively on the several solar technologies requiring the use of silver and concluded that these could provide a significant fraction of future world electricity under the condition that the reduction in silver content in the cells proceeds at an adequate pace Their model rested on the assumption that the market share for this application would not have overcome the 5% threshold. While the research results in the use of coppernickel alloys for the frontal contact metallization are promising, the experts from the field agree that the total substitution of silver is still an unresolved matter for the forthcoming years (Schubert et al, 2013)

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