Greenhouse gas emissions associated with photovoltaic electricity from crystalline silicon modules under various energy supply options

The direct and indirect emissions associated with photovoltaic (PV) electricity generation are evaluated, focussing on greenhouse gas (GHG) emissions related to crystalline silicon (c-Si) solar module production. Electricity supply technologies used in the entire PV production chain are found to be most influential. Emissions associated with only the electricity-input in the production of PV vary as much as 0-200 g CO(2)-eq per kWh electricity generated by PV. This wide range results because of specific supply technologies one may assume to provide the electricity-input in PV production, i.e., whether coal-, gas-, wind-, or PV-power facilities in the background provide the electricity supply for powering the entire PV production chain. The heat input in the entire PV production chain, for which mainly the combustion of natural gas is assumed, adds another similar to 16 CO(2)-eq/kWh. The GHG emissions directly attributed to c-Si PV technology alone constitute only similar to 1-2 g CO(2)-eq/kWh. The difference in scale indicates the relevance of reporting indirect emissions due to energy input in PV production separately from direct emissions particular to PV technology. In this article, we also demonstrate the utilization of direct and indirect shares of emissions for the calculation of GHG emissions in simplified world electricity-and PV-market development scenarios. Results underscore very large GHG mitigation realized by solar PV toward increasingly significant PV market shares. Copyright (C) 2011 John Wiley & Sons, Ltd.