Life-cycle nitrogen trifluoride emissions from photovoltaics.
Amorphous- and nanocrystalline-silicon thin-film photovoltaic modules are made in high-throughput manufacturing lines that necessitate quickly cleaning the reactor. Using NF₃, a potent greenhouse gas, as the cleaning agent triggered concerns as recent reports reveal that the atmospheric concentrations of this gas have increased significantly. We quantified the life-cycle emissions of NF₃ in photovoltaic (PV) manufacturing, on the basis of actual measurements at the facilities of a major producer of NF₃ and of a manufacturer of PV end-use equipment. From these, we defined the best practices and technologies that are the most likely to keep worldwide atmospheric concentrations of NF₃ at very low radiative forcing levels. For the average U.S. insolation and electricity-grid conditions, the greenhouse gas (GHG) emissions from manufacturing and using NF₃ in current PV a-Si and tandem a-Si/nc-Si facilities add 2 and 7 g CO₂(eq)/kWh, which can be displaced within the first 1-4 months of the PV system life.
Brookhaven National Laboratory and Columbia University, New York, New York, USA. vmf@bnl.gov
Vasilis
V
Fthenakis
Daniel O
DO
Clark
Mehran
M
Moalem
Phil
P
Chandler
Robert G
RG
Ridgeway
Forrest E
FE
Hulbert
David B
DB
Cooper
Peter J
PJ
Maroulis
D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry; D011211:Electric Power Supplies; D059029:Electronic Waste / Q000032:analysis*; D004784:Environmental Monitoring; D005459:Fluorides / Q000032:analysis*; D007220:Industrial Waste / Q000032:analysis*; D008420:Manufactured Materials / Q000032:analysis; D017672:Nitrogen Compounds / Q000032:analysis*; D012993:Solar Energy; D018505:Waste Management / Q000379:methods
D000393:Air Pollutants; D007220:Industrial Waste; D017672:Nitrogen Compounds; C534617:nitrogen trifluoride; D005459:Fluorides