Changes of solar cell parameters during damp-heat exposure

The degradation of PV modules during damp-heat exposure is investigated. Power degradation is analysed in dependence of temperature and humidity during exposure. The module’s equivalent circuit parameters are calculated from I-V characteristics measured during ageing. A dose function is developed and degradations of power as well as equivalent circuit parameters can be analysed against the dose, which provides a better understanding of the module ageing behaviour. EL images of modules before and after ageing support the changes of solar cell parameters

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

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%

Attribution diagram.

<p>Attribution diagram: transmission routes to the point-of-exposure included in the expert elicitation [from ref. 2]. It is assumed that the pathways are mutually exclusive and exhaustive.</p

Statistical accuracy and informativeness of Performance Weights and Equal Weights Panel.

<p>Statistical accuracy and informativeness of Performance Weights (PW DM) and Equal Weights Panel (EW DM), and corresponding DM joint scores (symbol size); the thin grey lines join PW DM and EW DM solutions for individual Panels (see text). The vertical red line denotes the traditional 5% confidence level rejection threshold; the horizontal blue line is solely for comparison with Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149817#pone.0149817.g004" target="_blank">4</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149817#pone.0149817.g005" target="_blank">5</a>. Symbol size indicates Panel DM combined score: largest = 1.12; smallest = 0.012.</p

Statistical accuracy and informativeness of the Equal Weights panel EW DMs.

<p>Statistical accuracy and informativeness of the Equal Weights panel EW DMs. The vertical red line denotes the traditional 5% confidence level rejection threshold; the horizontal blue line is solely for comparison with Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149817#pone.0149817.g005" target="_blank">5</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149817#pone.0149817.g007" target="_blank">7</a>. Symbol size indicates Panel DM combined score: largest = 0.50; smallest = 0.035.</p

WHO sub-regions.

<p>WHO sub-regions: expert panels provided estimates for each sub-region, from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0149817#pone.0149817.ref002" target="_blank">2</a>].</p

Categories of calibration variables.

<p>Categories of calibration variables.</p

Experts and panels.

<p>Left: histogram of number of panels for number of experts; right: histogram of number of panels for number of calibration variables.</p

Affinity Protein-Based FRET Tools for Cellular Tracking of Chitosan Nanoparticles and Determination of the Polymer Degree of Acetylation

Chitosan (CS) is a family of linear polysaccharides with diverse applications in medicine, agriculture, and industry. Its bioactive properties are determined by parameters such as the degree of acetylation (DA), but current techniques to measure the DA are laborious and require large amounts of substrate and sophisticated equipment. It is also challenging to monitor the fate of chitosan-based nanoparticles (CS-NPs) in vitro because current tools cannot measure their enzymatic or chemical degradation. We have developed a method based on the Förster resonance energy transfer (FRET) that occurs between two independent fluorescent proteins fused to a CS-binding domain, who interact with CS polymers or CS-NPs. We used this approach to calibrate a simple and rapid analytical method that can determine the DA of CS substrates. We showed unequivocally that FRET occurs on the surface of CS-NPs and that the FRET signal is quenched by enzymatic degradation of the CS substrate. Finally, we provide in vitro proof-of-concept that these approaches can be used to label CS-NPs and colocalize them following their interactions with mammalian cells