Moisture sensor at glass/polymer interface for monitoring of photovoltaic module encapsulants

Carlsson, Thomas; Halme, Janne; Lund, Peter; Konttinen, P.

doi:10.1016/j.sna.2005.07.022

Cited by 15 publications

(10 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By using previously determined properties of moisture diffusion and solubility of used materials, it is possible to simulate the moisture ingress in PV modules using approximate analytical relations [13], [14] or Finite Element Modelling (FEM) [15]. Some attempts of in-situ moisture measurement methods have also been reported using different self-made moisture sensors with combination of external impedance spectroscopy instruments [16]- [18]. Although they give results that are consistent with simulations they all require thorough calibration procedures and cumbersome instrumentation.…”

Section: Introductionmentioning

confidence: 99%

<italic>In-Situ</italic> Monitoring of Moisture Ingress in PV Modules Using Digital Humidity Sensors

Jankovec

Galliano

Annigoni

et al. 2016

IEEE J. Photovoltaics

View full text Add to dashboard Cite

A new in-situ moisture monitoring technique for PV modules is proposed using miniature digital humidity and temperature sensors. The sensors were embedded in three different ethylene-vinyl-acetate (EVA) stacks and proved to be resistant to lamination conditions. The fact that they are in direct contact to EVA does not affect their performance since their saturated relative humidity (RH) reading is proportional to the external RH in the air. By exposing the sensors to elevated temperature and RH conditions, water vapor transmission rate (WVTR) of the backsheet and diffusion coefficient of the EVA can be determined. Obtained coefficients agree with reference values within their measurement uncertainties. Besides determining material moisture ingress properties, this monitoring technique is also applicable for long-term outdoor PV module monitoring. It shall provide valuable location and installation specific information of RH and temperature stress conditions, especially as a feedback information to manufacturers of materials and PV modules.

show abstract

Section: Introductionmentioning

confidence: 99%

<italic>In-Situ</italic> Monitoring of Moisture Ingress in PV Modules Using Digital Humidity Sensors

Jankovec

Galliano

Annigoni

et al. 2016

IEEE J. Photovoltaics

View full text Add to dashboard Cite

show abstract

“…The spectral fingerprints in both spectral regions, the OH stretching and bending regions, gave direct evidence of water in 'dry' nanoporous TiO2 films. Indeed, nanoporous TiO2 films are known to adsorb water from the ambient air due to the hydrophilic nature of the TiO2 surface and the capillary 8 condensation of water in the smallest nanopores, 55,56 even to the extent that they can be used as humidity sensors 57,58 . In a DSC, presence of water on TiO2 surfaces can hinder the excited-state charge transfer which can adversely affect the device performance 59 .…”

Section: Resultsmentioning

confidence: 99%

“…Indeed, nanoporous TiO 2 films are known to adsorb water from the ambient air due to the hydrophilic nature of the TiO 2 surface and the capillary condensation of water in the smallest nanopores, 55,56 even to the extent that they can be used as humidity sensors. 57,58 In a DSC, the presence of water on TiO 2 surfaces can hinder the excited-state charge transfer which can adversely affect the device performance. 59 To avoid capillary condensation and adsorption of water in the TiO 2 films, it has been recommended that the films are dipped in the dye solutions, while they are still warm after the high-temperature annealing step, and dried under dry air or nitrogen.…”

Section: ■ Resultsmentioning

confidence: 99%

“…The spectral fingerprints in both spectral regions, the OH stretching and bending regions, gave direct evidence of water in “dry” nanoporous TiO 2 films. Indeed, nanoporous TiO 2 films are known to adsorb water from the ambient air due to the hydrophilic nature of the TiO 2 surface and the capillary condensation of water in the smallest nanopores, , even to the extent that they can be used as humidity sensors. , In a DSC, the presence of water on TiO 2 surfaces can hinder the excited-state charge transfer which can adversely affect the device performance . To avoid capillary condensation and adsorption of water in the TiO 2 films, it has been recommended that the films are dipped in the dye solutions, while they are still warm after the high-temperature annealing step, and dried under dry air or nitrogen. , An interesting observation was that the OH bending bands showed significant sample-to-sample variation, although the TiO 2 films were fabricated, handled, and measured under practically identical conditions (Figure S1).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Intriguing Photochemistry of the Additives in the Dye-Sensitized Solar Cells

et al. 2016

Self Cite

View full text Add to dashboard Cite

Over the years numerous mixes of chemical compounds have been tried in the electrolytes of dye-sensitized solar cells in efforts to improve their efficiency. How these chemicals interact with each other and the photoelectrode has received surprisingly little attention. Here we report results from a systematic study of two I-/I3electrolytes and their additives using infrared and Raman spectroscopy together with quantum chemical calculations. In the LiI electrolyte competing interactions between lithium cation and the solvent MPN and the additives TBP, NMBI and GuSCN were identified. These interactions could inhibit the interaction of lithium ions with the TiO2 surface. It was found that under Raman excitation of PMII solution in contact with the photoelectrode, efficient generation of I3takes place. For LiI solution, in addition, a Dye-I2 complex is formed. The results could be explained by diffusion limited build-up of I3and depletion of Iconcentrations in the focal area of the excitation beam and by reduction of I3via conduction band electrons of TiO2 beyond the focal region. To explain the formation of Dye-I2 complexes in the LiI electrolyte solutions a multi-step regeneration mechanism is proposed. It was found that GuSCN reduces the I3concentration in the electrolyte solutions studied, in the LiI electrolyte in addition it binds to lithium ions and nearly depletes the Dye-I2 complexes. From infrared spectra, it became clear that preventing water entering the DSCs during the preparation stages in ambient air is a demanding task. The identified interactions paint an intriguing new photochemical landscape of the function of the dye-sensitized solar cells giving guidelines for further development of the devices.

show abstract

“…In-situ module monitoring methods have been developed for different types of accelerated stress tests, stress factors and degradation parameters. Module moisture monitoring during accelerated aging tests for PV module encapsulants, was proposed by Carlsson et al [2], by integrating a moisture sensor inside thin-film modules. Tanahashi et al [3] proposed in-situ monitoring of AC impedance parameters of PV modules undergoing rapid thermal cycling stress tests, for detecting solder bond failures after prolonged test cycles.…”

Section: Introductionmentioning

confidence: 99%

In-Situ Measurement of Power Loss for Crystalline Silicon Modules Undergoing Thermal Cycling and Mechanical Loading Stress Testing

2020

View full text Add to dashboard Cite

An in-situ method is proposed for monitoring and estimating the power degradation of mc-Si photovoltaic (PV) modules undergoing thermo-mechanical degradation tests that primarily manifest through cell cracking, such as mechanical load tests, thermal cycling and humidity freeze tests. The method is based on in-situ measurement of the module’s dark current-voltage (I-V) characteristic curve during the stress test, as well as initial and final module flash testing on a Sun simulator. The method uses superposition of the dark I-V curve with final flash test module short-circuit current to account for shunt and junction recombination losses, as well as series resistance estimation from the in-situ measured dark I-Vs and final flash test measurements. The method is developed based on mc-Si standard modules undergoing several stages of thermo-mechanical stress testing and degradation, for which we investigate the impact of the degradation on the modules light I-V curve parameters, and equivalent solar cell model parameters. Experimental validation of the method on the modules tested shows good agreement between the in-situ estimated power degradation and the flash test measured power loss of the modules, of up to 4.31 % error (RMSE), as the modules experience primarily junction defect recombination and increased series resistance losses. However, the application of the method will be limited for modules experiencing extensive photo-current degradation or delamination, which are not well reflected in the dark I-V characteristic of the PV module.

show abstract

Moisture sensor at glass/polymer interface for monitoring of photovoltaic module encapsulants

Cited by 15 publications

References 13 publications

<italic>In-Situ</italic> Monitoring of Moisture Ingress in PV Modules Using Digital Humidity Sensors

<italic>In-Situ</italic> Monitoring of Moisture Ingress in PV Modules Using Digital Humidity Sensors

Intriguing Photochemistry of the Additives in the Dye-Sensitized Solar Cells

In-Situ Measurement of Power Loss for Crystalline Silicon Modules Undergoing Thermal Cycling and Mechanical Loading Stress Testing

Contact Info

Product

Resources

About