A scaling law for monocrystalline PV/T modules with CCPC and comparison with triple junction PV cells

Scaling laws serve as a tool to convert the five parameters in a lumped one-diode electrical model of a photovoltaic (PV) cell/module/panel under indoor standard test conditions (STC) into the parameters under any outdoor conditions. By using the transformed parameters, a current-voltage curve can be established under any outdoor conditions to predict the PV cell/module/panel performance. A scaling law is developed for PV modules with and without crossed compound parabolic concentrator (CCPC) based on the experimental current-voltage curves of six flat monocrystalline PV modules collected from literature at variable irradiances and cell temperatures by using nonlinear least squares method. Experiments are performed to validate the model and method on a monocrystalline PV cell at various irradiances and cell temperatures. The proposed scaling law is compared with the existing one, and the former exhibits a much better accuracy when the cell temperature is higher than 40 °C. The scaling law of a triple junction flat PV cell is also compared with that of the monocrystalline cell and the CCPC effects on the scaling law are investigated with the monocrystalline PV cell. It is identified that the CCPCs impose a more significant influence on the scaling law for the monocrystalline PV cell in comparison with the triple junction PV cell. The proposed scaling law is applied to predict the electrical performance of PV/thermal modules with CCPC

Conceptual design and performance evaluation of a hybrid concentrating photovoltaic system in preparation for energy

Concentrating sunlight and focussing it on smaller sized solar cells increases the device's power output per unit active area. However, this process tends to increase the solar cell temperature considerably and has the potential to compromise system reliability. Adding a heat exchanger system to regulate this temperature rise, can improve the electrical performance whilst simultaneously providing an additional source of low temperature heat. In this study the performance of a low concentrator photovoltaic system with thermal (LCPV/T) extraction was conceptualised and evaluated in depth. An experimental analysis was performed using a first-generation prototype consisting of 5 units of Cross Compound Parabolic Concentrators (CCPC) connected to a heat extraction unit. A bespoke rotating table was used as experimental apparatus to effectively evaluate the optical performance of the system, as a function of its angular positions to replicate the motion of actual sun. Key design performance parameters for the LCPV/T collector are presented and discussed. This work also provides a useful technique to effectively calculate system performance, as a function of the orientation-dependant electrical characterisation parameters data. Finally, a Computational Fluid Dynamics (CFD) model was also applied to investigate the efficacy of the heat exchanger and hence estimate the overall co-generation benefit of using such optimisation techniques on realistic CPV systems. It was highlighted through these simulations that the water flow rate had the potential to be a critical power-generation optimisation criterion for LCPV-T systems. The maximum power output at normal incidence with concentrators and no water flow was found to be 78.4 mW. The system was found to perform with an average electrical efficiency ranging between 10 and 16% when evaluated at five different geographic locations. Experimental analysis of the data obtained showed an increase in power of 141% (power ratio 2.41) compared to the analogous non-concentrating counterpart. For example, in the case of London which receives an annual solar radiation of 1300 kWh/m2 the system is expected to generate 210 kWh/m2. This may reduce further to include losses due to temperature, reflectance/glazing losses, and electrical losses in cabling and inverter by up to 36% leading to an annual power output of 134 kWh/m2 of module

A coupled optical-thermal-electrical model to predict the performance of hybrid PV/T-CCPC roof-top systems

A crossed compound parabolic concentrator (CCPC) is applied into a photovoltaic/thermal (PV/T) hybrid solar collector, i.e. concentrating PV/T (CPV/T) collector, to develop new hybrid roof-top CPV/T systems. However, to optimise the system configuration and operational parameters as well as to predict their performances, a coupled optical, thermal and electrical model is essential. We establish this model by integrating a number of submodels sourced from literature as well as from our recent work on incidence-dependent optical efficiency, six-parameter electrical model and scaling law for outdoor conditions. With the model, electrical performance and cell temperature are predicted on specific days for the roof-top systems installed in Glasgow, Penryn and Jaen. Results obtained by the proposed model reasonably agree with monitored data and it is also clarified that the systems operate under off-optimal operating condition. Long-term electric performance of the CPV/T systems is estimated as well. In addition, effects of transient terms in heat transfer and diffuse solar irradiance on electric energy are identified and discussed

First record of Eufriesea laniventris (Ducke, 1902) (Hymenoptera, Apidae, Euglossini) in the state of Amazonas, Brazil

The first record of Eufriesea laniventris in the state of Amazonas is here reported. Attracted to 1.8 cineole and methyl salicylate fragrances, six specimens were colected in the region of Manaus (2º 36' S 60º 02' W) during the year 2000.", 'enÉ registrada pela primeira vez a ocorrência de Eufriesea laniventris no Amazonas. No ano 2000, foram coletados seis exemplares na região de Manaus (2º 36' S e 60º 02' W) atraídos pelas substâncias odoríferas 1,8 cineol e salicilato de metila

Dynamic moment of inertia of the 192Hg superdeformed band at high rotational frequencies

The superdeformed band in 192Hg has been extended to higher transition energies from a new analysis of a large set of double and triple coincidence data. Contrary to the results of cranked shell model calculations including monopole pairing, the dynamic moment of inertia I(2) is found to continue to increase with rotational frequency

Feeding of superdeformed bands: The mechanism and constraints on band energies and the well depth

Entry distributions leading to normal and superdeformed (SD) states in Hg192 have been measured. A model, based on Monte Carlo simulations of γ cascades, successfully reproduces the entry distribution for SD states, as well as all other known observables connected with the population of SD states. Comparison of experimental and model results, together with the measured SD entry distribution, suggest that the SD band lies 3.3-4.3 MeV above the normal yrast line when it decays around spin 10 and that the SD well depth is 3.5-4.5 MeV at spin 40

Superdeformed band in Hg192

The observation of a superdeformed band in the nucleus Hg192 is reported. The band has sixteen transitions with an average energy spacing of 36 keV and an average dynamic moment of inertia scrI(2) of 112 Latin small letter h with stroke2 MeV-1. This band persists to rather low rotational frequency (Latin small letter h with stroke0.125 MeV) and is proposed to extend in spin from 10+ to 42+. No transitions linking the superdeformed states and the low deformation yrast levels were found and the decay out of the superdeformed band appears to be statistical. This is the second case of superdeformation in the 190 region

Gamma ray studies of neutron-rich sdf shell nuclei produced in heavy ion collisions

Reanalysis of ichproductsofbinaryreactio nsof$34S, S36, and Cl37 beams on Gd160 targets. Gates set on known amma$raysin$A∼160 products selected individual react ion channels and identified coincident amma$raysin$A∼36 partner products. Transfers of protons from projectile to target and of neutrons from target to projectile were generally favored, leading to excited neutron-rich light nuclei, including some difficult to reach by other means. Notable results include the observation of amma$raycascadesupthehigh e stknownyraststatesinfour$N=20 isotones. In two N=19 nuclei, Si33 and P34, the two N=22 nuclei, S38 and Cl39, previously unknown yrast states were identified

Lifetime measurements in the superdeformed band of Hg192

Lifetimes were measured for transitions in the superdeformed band of Hg192 with the Doppler-shift attenuation method. The results yield an essentially constant quadrupole moment of 202 e b and indicate that the sidefeeding lifetimes are of the same order as the state lifetimes. The data are consistent with calculations using the cranked Woods-Saxon Strutinsky method with pairing