摘要:The challenge of stabilizing global carbon emissions over the
next 50 years has been framed in the context of finding seven 1.0 Gton C/year carbon reduction wedges. Solar photovoltaics (PV) could provide at least one carbon wedge,
but will require significant growth in PV manufacturing capacity. The actual amount of
installed PV capacity required to reach wedge-level carbon reductions will vary greatly
depending on the mix of avoided fuels and the additional emissions from manufacturing PV
capacity. In this work, we find that the US could reduce its carbon emissions by 0.25 Gton C/year, equal to the fraction of a global carbon wedge proportional to its current
domestic electricity use, by installing 792–811 GW of PV capacity. We evaluate
a series of PV growth scenarios and find that wedge-level reductions could be
met by increasing PV manufacturing capacity and annual installations by 0.95 GW/year/year each year from 2009 to 2050 or by increasing up to 4 GW/year/year for a period of 4–17 years for early and late growth scenarios. This challenge of increasing
PV manufacturing capacity and market demand is significant but not out of line with the
recent rapid growth in both the global and US PV industry. We find that the rapid
growth in PV manufacturing capacity leads to a short term increase in carbon
emissions from the US electric sector. However, this increase is small, contributing
less than an additional 0.3% to electric sector emissions for less than 4.5 years,
alleviating recent concern regarding carbon emissions from rapid PV growth scenarios.