The impact of high temperature and irradiance source on the efficiency of polycrystalline photovoltaic panel in a controlled environment

Solar cells are highly sensitive to temperature, which affects its operating parameters. The study has its aim in accessing the impact of temperature (in excess above the maximum operating cell temperature) and irradiance source on the efficiency of polycrystalline photovoltaic (PV) solar panels in an environment where the temperature and irradiance level can be fully controlled. For the study to achieve its aim, a solar box and tungsten light bulbs were used to create an environment where the irradiance level and the temperature can be controlled. The solar panel was placed inside the solar box facing the light source while the irradiance level and temperature were measured and held constant. Results show a steady decrease in voltage with increasing temperature while the performance ratio and efficiency of the photovoltaic module followed a similar trend as that of voltage once the temperature exceeds the maximum operating cell temperature. Results also show the output voltage of the photovoltaic to be higher under the tungsten light than the sun, but the efficiency achieved by the photovoltaic under the sun far exceeds that obtained under the tungsten light.

Modelling the leakage current in a solid oxide fuel cell with bi-layer electrolyte

<p class="PaperAbstract">A mathematical model is developed to study the leakage current in a solid oxide fuel cell (SOFC) with a bi-layer electrolyte. The model predicts the variation of leakage current and power density with various design and operating factors of SOFC, namely thickness of the bi-layer electrolyte, operating temperature and operating cell voltage. The interfacial oxygen pressure in SOFC is also studied as a function of the thickness of YSZ layer. Modelling results are compared with experimental data and found to compare well.</p>

Numerical and Experimental Study of an Asymmetric CPC-PVT Solar Collector

Photovoltaic (PV) panels and thermal collectors are commonly known as mature technologies to capture solar energy. The efficiency of PV cells decreases as operating cell temperature increases. Photovoltaic Thermal Collectors (PVT) offer a way to mitigate this performance reduction by coupling solar cells with a thermal absorber that can actively remove the excess heat from the solar cells to the Heat Transfer Fluid (HTF). In order for PVT collectors to effectively counter the negative effects of increased operating cell temperature, it is fundamental to have an adequate heat transfer from the cells to the HTF. This paper analyzes the operating temperature of the cells in a low concentrating PVT solar collector, by means of both experimental and Computational Fluid Dynamics (CFD) simulation results on the Solarus asymmetric Compound Parabolic Concentrator (CPC) PowerCollector (PC). The PC solar collector features a Compound Parabolic Concentrator (CPC) reflector geometry called the Maximum Reflector Concentration (MaReCo) geometry. This collector is suited for applications such as Domestic Hot Water (DHW). An experimental setup was installed in the outdoor testing laboratory at Gävle University (Sweden) with the ability to measure ambient, cell and HTF temperature, flow rate and solar radiation. The experimental results were validated by means of an in-house developed CFD model. Based on the validated model, the effect of collector tilt angle, HTF, insulation (on the back side of the reflector), receiver material and front glass on the collector performance were considered. The impact of tilt angle is more pronounced on the thermal production than the electrical one. Furthermore, the HTF recirculation with an average temperature of 35.1 °C and 2.2 L/min flow rate showed that the electrical yield can increase by 25%. On the other hand, by using insulation, the thermal yield increases up to 3% when working at a temperature of 23 °C above ambient.

Establishment of Standard Reference Environment for Photovoltaic Nominal Operating Cell Temperature Testing with Dedicated Approach for Tropical Region

<p>This paper presents the establishment of Standard Reference Environment (SRE) for photovoltaic (PV) Nominal Operating Cell Temperature (NOCT) testing in Malaysia representing one of the countries that lies in tropical region. From a field testing conducted, 12-months data of six parameters namely solar irradiance (SI), ambient temperature (AT), relative humidity (RH), wind speed (WS), wind direction (WD), module temperature (MT) and open circuit voltage were analysed to determine the median SI and the median AT. From the analysis, the median SI and the median AT are 228 W/m²and 30 °C respectively. However, these results show that the current approach in determining SRE using median ambient parameters is not suitable for tropical Malaysia based on the percentage error of approximately 30 %. Due to this, the proposed approach applied in this study is determining the corresponding AT of the same SI (800 W/m²) used in present SRE of international standard. Thus, the new proposed SI and AT for SRE in this study are 800W/m² and 31°C respectively. The SRE found in this study is determined using dedicated approach to suit tropical climate in deriving a more accurate NOCT for tropical region.<em></em></p>

Recent developments in photovoltaic-thermoelectric combined system

The photovoltaic system converts solar radiation into electricity. The output of the solar photovoltaic systems is strongly depending on the operating cell temperature. The power output of photovoltaic system reduces as the operating cell temperature increases. Several techniques have been reported in the literature to maintain the low operating temperature of the solar cell by utilizing module heat for separate thermal application. Integration of photovoltaic thermoelectric (PV-TE) system is one of these techniques. In these PV-TE systems, the hot junctions of thermoelectric modules are coupled with the photovoltaic. The thermoelectric module uses heat from PV system and generates additional power. This PV-TE system not only generates more power but also improves the PV efficiency. The present article reports a comprehensive review of latest developments in the PV-TE systems. A detailed classification, key outcomes of published research and the future research scope are discussed in this article.

Evaluation of Standard Reference Environment for Photovoltaic Nominal Operating Cell Temperature Testing in Malaysia

<p>This paper presents six months evaluation in determining Standard Reference Environment (SRE) for Photovoltaic (PV) Nominal Operating Cell Temperature (NOCT) testing of IEC61215 and IEC61646 that suits Malaysian climate. The SRE is established based on the median environmental conditions in Malaysia when solar PV is producing power. The site of the study is located at the Energy and Environment Field Lab, Universiti Teknologi MARA (UiTM) Shah Alam(3.066239ºN, 101.491685ºE). Three types of PV module technologies involved are monocrystalline, polycrystalline and copper indium diselenide (CIS) thin film. The experimental setup is a test bed that meets the IEC61215, IEC61646 and IEC61724 requirements. The measurements of module temperature (MT) and open circuit voltage (V_OC) are taken simultaneously for the three PV module technologies together with other ambient parameters of solar irradiance(SI), ambient temperature(AT), relative humidity(RH), wind speed (Ws) and wind direction(Wd). The data set is taken for a six months period from February 2017 to July 2017. Based on the results obtained, a new proposed SRE of NOCT testing for IEC61215 and IEC61646 has been established to suit Malaysian climate. The SI and AT values for the SRE are 300W/m² and 31°C respectively.</p>

Estimation of Most Frequent Conditions and Performance Evaluation of Three Photovoltaic Technology Modules

In this paper, a performance evaluation technique using most frequent conditions (MFC) for accurate design of photovoltaic systems, based on energy rating and site-specific standards is reported. Most frequent conditions are estimated for the three different technologies: multicrystalline silicon (mc-Si), amorphous silicon (a-Si), and hetero-junction with intrinsic thin layer (HIT) for the site based on air-mass, module temperatures, incident in-plane irradiance, and power output. The performances are analyzed over a period of 3 years by evaluating changes in the performance ratio, the energy yields, and the percentages of occurrence of data points corresponding to standard test condition (STC), nominal operating cell temperature (NOCT), and MFC. For MFC, performance ratio (PR) values are ranging from 0.70 to 0.83, 0.70 to 0.86, and 0.70 to 0.90 for mc-Si, a-Si, and HIT, respectively. The total energy yield of HIT is the highest followed by a-Si and mc-Si modules for this climatic zone.