This paper presents results obtained from monitoring a 1.72 kWp photovoltaic system installed on a flat roof of a 12 m high building in Dublin, Ireland (latitude 53.4°N and longitude 6.3°E). The system was monitored between November 2008 and October 2009 and all the electricity generated was fed into the low voltage supply to the building. Monthly average daily and annual performance parameters of the PV system evaluated include: final yield, reference yield, array yield, system losses, array capture losses, cell temperature losses, PV module efficiency, system efficiency, inverter efficiency, performance ratio and capacity factor. The maximum solar radiation, ambient temperature and PV module temperature recorded were 1241 W/m2 in March, 29.5 °C and 46.9 °C in June respectively. The annual total energy generated was 885.1 kW h/kWp while the annual average daily final yield, reference yield and array yield were 2.41 kW h/kWp/day, 2.85 kW h/kWp/day and 2.62 kW h/kWp/day respectively. The annual average daily PV module efficiency, system efficiency and inverter efficiency were 14.9%, 12.6% and 89.2% respectively while the annual average daily performance ratio and capacity factor were 81.5% and 10.1% respectively. The annual average daily system losses, capture losses and cell temperature losses were 0.23 h/day, 0.22 h/day and 0.00 h/day respectively. Comparison of this system with other systems in different locations showed that the system had the highest annual average daily PV module efficiency, system efficiency and performance ratio of 14.9%, 12.6% and 81.5% respectively. The PV system’s annual average daily final yield of 2.4 kW h/kWp/day is higher than those reported in Germany, Poland and Northern Ireland. It is comparable to results from some parts of Spain but it is lower than the reported yields in most parts of Italy and Spain. Despite low insolation levels, high average wind speeds and low ambient temperature improve Ireland’s suitability.

Measured Performance of a 1.72 kW Rooftop Grid Connected Photovoltaic System in Ireland

Battery energy storage systems are becoming more and more popular solution in the household applications, especially, in combination with renewable energy sources. The bidirectional AC-DC power electronic converter have great impact to the overall efficiency, size, mass and reliability of the storage system. This paper reviews the literature that deals with high efficiency converter technologies for connecting low voltage battery energy storage to an AC distribution grid. Due to low voltage of the battery isolated bidirectional AC-DC converter or a dedicated topology of the non isolated converter is required. Review on single stage, two stage power converters and integrated solutions are done in the paper.

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An Overview of Bidirectional AC-DC Grid Connected Converter Topologies for Low Voltage Battery Integration

The performance of solar systems is influenced by external environmental as weather, climates and irradiation, while for internal factors as conductivity, interfaces homogeneous and material, it can be improved by configuring the optimal characteristics of the solar system. Accurately, the thermal interfacial resistance in the different components of solar system influences significantly the transformation of solar energy into electricity and heat for the reason that heat transfer dropping between phase change material (PCM) and photovoltaic system. In this study, a novel engineering of a hybrid solar system that purposes to increase electrical energy in the photovoltaic (PV) system by absorbing heat has been proposed. The proposed system integrates two types of PCM in order to increase the thermal stability time, reduce the temperature variation and optimize the efficiency of thermal production. Moreover, the interface of contact has been improved and homogenized in order to optimize the heat exchange between the components of the systems which is increasing the evacuation of heat for the PCM that optimized the production of electricity and heat. Consequently, a systematic study evaluates the efficiency of the PV/PCM system in terms of electrical and thermal production has been proposed. Hence, the numerical study showed that there is a similarity between the results obtained and the previous results, and there is an obvious improvement after adding two types of PCM with different melting point compared to PV system with one type of PCM or without PCM. Electrical power output has been improved significantly that reaches 54.5% in the beginning of the day compared to PV without PCM and the electrical efficiency grows by about 34% compared to PV without PCM and can achieve 42.5% with two PCM. The absorbed heat can increase the production of thermal energy after optimizing the interface of contact that can be achieved about 52% compared to a system PV without PCM and the productivity can reach 63% with proposed system PV with two PCM. 

Optimizing the conception of hybrid PV/PCM by optimizing the heat transfer at the contact interface and by integrating two types of PCM

Critical Examination of the Role of Silica Nanoparticle Dispersions in Heat Transfer Fluid for Solar Applications

This article presents a detailed analysis of the performance, rate of degradation, and power and energy loss of a 1 MWp scale solar photovoltaic (PV) plant in the academic institution GITAM (Deemed to be University), located in the coastal region of Andhra Pradesh, India. The PV plant consists of 3,078 polycrystalline PV modules of 325 Wp rating, installed on the rooftop of the institute buildings. The annual energy generated is 1684.881 MWh. In this study, performance analysis involves the calculation of efficiency, capacity factor, and performance ratio with data simulated using the PVsyst tool. Degradation analysis involves energy light-induced degradation (LID) and degradation rate (DR). The predicted result provides an estimate for optimal functioning of PV plant with an annual capacity factor, performance ratio, and energy loss of 11.3%, 87.9%, and −26%, respectively. Energy loss by light-induced degradation is predicted as −2.7%/year, and the degradation rate of module per year is −0.6% to −5%.

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Analysis on Large-Scale Solar PV Plant Energy Performance–Loss–Degradation in Coastal Climates of India

Photovoltaic (PV) cells are used to convert solar energy into usable direct current as an output power source. Temperatures of PV module exceeding 25 °C reduce conversion rates by 0.4 to 0.65%/0C. In order to keep PV cells working at their optimal operating temperature, a variety of heat extraction systems have been developed. Another method that may be utilized for both heat absorption and temperature management is phase change material (PCM), which has a high thermal energy absorption capacity while also maintaining a constant temperature range throughout phase transition. One of the most efficient ways to absorb extra heat off the backside of solar panels is using PCM, which allows for improved energy efficiency. This article presents the findings of an experimental work of a PV system that includes a normal PV system, a PV system cooled with PCM, and a PV system cooled using nano phase change material (NPCM) for thermal management of the cell. Polyethylene glycol (PEG) 1000 with a melting temperature of 33-39 °C was employed as the PCM, while alumina and silica nanomaterial were used as the insertion materials in PCM. The findings indicate that adopting a PV-PCM, PV- Alumina nano phase change material (ANPCM), and PV-Silica nano phase change material (SNPCM) cooled system increases the system's electrical efficiency by 4.82, 8.1, and 7.17%, respectively, and increases power output by 5.12, 8.4, and 7.29%, respectively. In comparison to uncooled PV system, the panel temperature is lowered by 17.15%. Based on the findings, it seems that PCM and NPCM are effective means of controlling the temperature of PV solar cells. 

Investigation on the thermal management of solar photo voltaic cells cooled by phase change material

Enhancement of Heat Transfer in PEG 1000 Using Nano-Phase Change Material for Thermal Energy Storage


 Due to the increasing demand for energy worldwide, photovoltaic cooling systems have become an important field of research in recent years. The most important factor affecting the performance of a solar PV cell is its operating temperature. For harvesting heat from solar PV systems, phase change material (PCM) is regarded as the most effective material. As a result, this study discusses and describes the effect of using PCM and NanoPCM (NPCM) in cooling PV cells. This research reviews the various feasible hybrid PVT-PCM and PVT-NPCM methods used for cooling PV. The concept focusing on PV cooling technology is discussed where air, water and nanofluid are used as the working medium in combination with PCM and NPCM. It is observed that when high performance heat transfer and improved cooling rate are needed, active cooling methods are favoured, whereas passive cooling methods rely on themselves and don’t require extra power. It is also found that the effectiveness of applying PCM or NPCM for thermal control is heavily influenced by atmospheric air temperatures as well as the precise PCM or NPCM used. It is envisaged that this review will help new researchers better understand the qualities and capabilities of each cooling strategy. They are offered to help investigators quickly identify the basic science that led to the development of the thermal performance system and also improve the overall performance of the PV system.

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A comprehensive review on recent advancements in cooling of solar photovoltaic (PV) systems using phase change materials (PCMs)

Need for alternative energy sources to satisfy the rising demand in energy consumption elicited the research in the area of power converters/inverters. An increasing interest of using Z source inverter/converter in power generation involving renewable energy sources like wind and solar energy for both off grid and grid tied schemes were originated from 2003. This paper surveys the literature of Z source inverters/converter topologies that were developed over the years.

https://beei.org/index.php/EEI/article/viewFile/579/888

Z Source Inverter Topologies-A Survey

A single phase Z source inverter is developed for better voltage boosting and inversion ability suited for photovoltaic power generation systems. The operation of the Z source inverter is described with relevant equations. Simple boost scheme is used for switching actions of the inverter. The performance of the inverter used for photovoltaic applications can be checked with simulation and experimental results, which prove that it has single-stage buck and boost capability and improved reliability.

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M. Aravindan

Papers

Investigation on the thermal management of solar photo voltaic cells cooled by phase change material

Enhancement of Heat Transfer in PEG 1000 Using Nano-Phase Change Material for Thermal Energy Storage

A comprehensive review on recent advancements in cooling of solar photovoltaic (PV) systems using phase change materials (PCMs)

Z Source Inverter Topologies-A Survey

Experimental Verification of Single Phase Z Source Inverter for Photovoltaic Applications