3 research outputs found
Uncertainty in energy yield estimation based on C-Si module roundrobin results.
Results of the European FP7 Sophia project roundrobin
of c-Si module power measurements at STC and
low irradiance and temperature coefficients were used to
calculate annual energy yield at four sites. The deviation
in the estimates solely due to the different measurement
results is reported, neglecting the uncertainty in the
meteorological data and losses unrelated to the
performed measurements. While minimising the
deviation in Pmax measurements remains the key
challenge, the low irradiance and temperature
coefficient contributions are shown to be significant.
Propagating the measurement deviation in c-Si module
measurements would suggest that expanded uncertainty
in energy yield due to module characterization alone can
be as high as ±3-4%
Results of the Sophia module intercomparison part-1: stc, low irradiance conditions and temperature coefficients measurements of C-Si technologies
The results of a measurement intercomparison between eleven European laboratories measuring PV energy relevant parameters are reported. The purpose of the round-robin was to assess the uncertainty analyses of the participating laboratories on c-Si modules and to establish a baseline for the following thin-film round-robin. Alongside the STC measurements, low irradiance conditions (200W/m2) and temperature coefficients measurements were performed. The largest measurement deviation from the median at STC was for HIT modules from -3.6% to +2.7% in PMAX, but in agreement with the stated uncertainties of the participants. This was not the case for low irradiance conditions and temperature coefficients measurements with some partners underestimating their uncertainties. Larger deviations from the median from -5% to +3% in PMAX at low irradiance conditions and -6.6% to +18.3% for the PMAX temperature coefficient were observed. The main sources of uncertainties contributing to the spread in measurements were the RC calibration, mismatch factor and capacitive effects at STC and low irradiance conditions as well as the additional light inhomogeneity for the latter. The uncertainty in the junction temperature and the temperature deviation across the module were the major contributors for temperature coefficients measurements
Interlaboratory comparison of methodologies for measuring the angle of incidence dependence of solar cells
The aim of this work is to compare angle of incidence (AOI) measurement setups for solar cells between laboratories with such capability. For the first time, we compare relative light transmission measurements among eight laboratories, whose measurement techniques include indoor and outdoor methods. We present the relative
transmission measurements on three 156 mm x 156 mm crystalline-Si (c-Si) samples with different surface textures. The measurements are compared using the expanded uncertainties provided by each laboratory. Five of the eight labs showed an agreement better than ±2% to the weighted mean between AOIs from -75° to 70°. At AOIs of ±80° and ±85°, the same five labs showed a worst case deviation to the weighted mean of -3% to 5% and 0% to 18%, respectively. When
measurement uncertainty is considered, the results show that measurements at the highest incidence angle of ±85° are
problematic, as measurements from four out of the six labs reporting uncertainty were found non-comparable within their stated uncertainties. At 85° AOI a high to low range of up to 75% was observed between all eight laboratories