Title of article :
Distributed grid-connected photovoltaic power
system emission offset assessment: statistical test
of simulated- and measured-based data
Author/Authors :
R.J. Spiegel، نويسنده , , *، نويسنده , , M.R. Leadbetter b، نويسنده , , F. Chamu´ b، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2005
Abstract :
This study assesses the pollutant emission offset potential of distributed grid-connected photovoltaic (PV) power systems.
Computer-simulated performance results were utilized for 214 PV systems located across the US. The PV systems
monthly electrical energy outputs were based on a performance calculator called PVWATTS. Offset emissions of sulfur
dioxide (SO2), carbon dioxide (CO2), and nitrogen oxides (NOx) were determined from PV system outputs and average
utility emissions data from each state. For validation, the simulated monthly results were statistically compared with
measurement-based data (both production and corresponding emissions data) from 29 PV systems installed at different
sites across the US.
While the data shows high (geographic) variability, the substantial number of measurements allows reliable statistical
analysis. The methods are found to give consistent results in spite of the necessity to employ some even quite crude
input approximations—such as the use of statewide rather than specific emissions data for the systems. No significant
differences between simulated and measured monthly means for any of the pollutants were noted on the basis of individual
monthly analyses, though the results for NOx suggest the possible existence of some difference in that case. A
more detailed statistical modeling using all monthly data in one combined analysis (allowing improved variability estimation)
confirms these conclusions. Even the shorter confidence intervals for expected offsets obtained through the
combined analysis show no significant differences between simulated and measured methods for SO2 and CO2. The differences
for NOx are statistically significant but consistent—suggesting useful prediction by the simulations via a constant
correction factor. As expected, significant differences between months are evident for both simulated and
measured offsets.
Published by Elsevier Ltd.
Keywords :
Photovoltaic systems , Avoided emissions
Journal title :
Solar Energy
Journal title :
Solar Energy