Economic Advantages of Dry-Etched Black Silicon in Passivated Emitter Rear Cell (PERC) Photovoltaic Manufacturing

Chiara Modanese,Hannu Laine,Hele Savin,Joshua Pearce,Toni Pasanen

doi:10.3390/en11092337

Chiara Modanese, Hannu Laine + Show 3 more

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https://doi.org/10.3390/en11092337

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Abstract

Industrial Czochralski silicon (Cz-Si) photovoltaic (PV) efficiencies have routinely reached >20% with the passivated emitter rear cell (PERC) design. Nanostructuring silicon (black-Si) by dry-etching decreases surface reflectance, allows diamond saw wafering, enhances metal gettering, and may prevent power conversion efficiency degradation under light exposure. Black-Si allows a potential for >20% PERC cells using cheaper multicrystalline silicon (mc-Si) materials, although dry-etching is widely considered too expensive for industrial application. This study analyzes this economic potential by comparing costs of standard texturized Cz-Si and black mc-Si PERC cells. Manufacturing sequences are divided into steps, and costs per unit power are individually calculated for all different steps. Baseline costs for each step are calculated and a sensitivity analysis run for a theoretical 1 GW/year manufacturing plant, combining data from literature and industry. The results show an increase in the overall cell processing costs between 15.8% and 25.1% due to the combination of black-Si etching and passivation by double-sided atomic layer deposition. Despite this increase, the cost per unit power of the overall PERC cell drops by 10.8%. This is a significant cost saving and thus energy policies are reviewed to overcome challenges to accelerating deployment of black mc-Si PERC across the PV industry.

Highlights

The learning curve in the global photovoltaic (PV) industry [1,2,3,4,5] has resulted in continuous and aggressive reduction in the costs of solar modules [6,7]
The relative costs for all the processing steps for the texturized Czochralski silicon (Cz-Si) and black multicrystalline silicon (mc-Si) cells are shown in Figures 2 and 3, respectively; where the costs are normalized over the total cost of the respective passivated emitter rear cell (PERC) process
This study has presented the costs involved in the replacement of standard Cz-Si PERC cells with black-Si PERC cells

Summary

Introduction

The learning curve in the global photovoltaic (PV) industry [1,2,3,4,5] has resulted in continuous and aggressive reduction in the costs of solar modules [6,7]. PV installations provide a levelized cost of electricity (LCOE) lower than residential electricity prices from the grid [10] and at utility scales, PV is cost competitive with all conventional sources [11]. For the PV industry to expand electricity market share into the future [19], improving efficiencies is likely a key driver to further reduce the cost of solar energy [20]. This is because, historically, PV systems costs were lowered due to decreased module prices. Today, balance of systems (BOS) and installation costs make up a greater fraction of the systems costs

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