Investigations of ternary Cu3SbS3 thin films as absorber in photovoltaic devices

Magnetron sputtered Cu-Sb metallic precursors were sulphidised on glass and molybdenum/glass substrates at 6 different temperatures. Two techniques were adopted for the elemental sulphidisation process. Precursors sulphidised using evaporated elemental sulphur were successfully converted into Cu3SbS3 solar absorber layers on molybdenum substrates. The as-sulphidised films exhibited p-type conductivity were produced in the limited response when analysed using a Eu+ electrolyte arrangement to measure the photocurrent. The films exhibited an energy bandgap value of 1.84eV

Short-term performance variations of different photovoltaic system technologies under the humid subtropical climate of Kanpur in India

The study discusses the short-term performance variations of grid-connected photovoltaic (PV) systems installed in Kanpur, India. The analysis presents a holistic view of the performance variations of three PV array technologies [multi-crystalline (multi-Si), copper indium gallium diselenide and amorphous silicon] and two inverter types (high-frequency transformer and low-frequency transformer). The analysis considers the DC–AC conversion efficiency of the inverter, system performance through performance ratio (PR) calculations, energy variations between fixed and tracking systems and the comparison between calculated and simulated data for the examined period. The energy output difference between the tracking and fixed systems of the same PV technology show that these are dependent on differences in temperature coefficient, shading and other system related issues. The PR analysis shows the effect of temperature on the multi-Si system. The difference between the simulated and measured values of the systems was mostly attributed to the irradiance differences. Regarding the inverter evaluation, the results showed that both inverter types underperformed in terms of the conversion efficiency compared with nameplate values

A combined model for PV system lifetime energy prediction and annual energy assessment

This paper presents a generic model for the prediction of the lifetime energy production of photovoltaic (PV) systems and the assessment of their annual energy yield in different time periods of operation. As case studies, it considers domestic PV system generation potentials in the UK and India to demonstrate the model results across a range of contrasting climatic and operating conditions. The model combines long-term averages of solar data, a commercial PV system simulation package and a probability density function to express the range of the annual energy prediction in different time periods of system operation. Moreover, a sensitivity analysis based on degradation rates and energy output uncertainties is embedded in the lifetime energy calculations. The importance of the reliability and maintenance of the PV systems and the energy prediction risks, especially regarding economic viability, are demonstrated through the PV lifetime energy potentials in these two countries. It is shown that, even for countries that are significantly different in respect to their solar resource, PV systems may produce similar amounts of energy during their lifetime for reasonable assumptions of degradation rates and uncertainty levels

Thermophotovoltaic applications in the UK : critical aspects of system design

Almost 50 years of thermophotovoltaic (TPV) research from various sectors has resulted in a variety of potential applications and TPV technology options. In this work the potential of commercial TPV applications is assessed with specific reference to the UK. The assessment considers competing technologies for electricity generation, namely solar photovoltaics, external and internal heat engine generators, electro¬chemical cells and direct heat-to-electricity conversion devices. Electricity generation by TPV conversion from waste heat of industrial high-temperature processes is identified as one of the most suitable TPV applications. This market is examined in more detail using three specific high-temperature processes from the iron and steel and the glass sectors. Results are extrapolated to the entire UK high-temperature industry and include potential energy and CO2 savings. This work gathers knowledge from TPV and other literature sources and evaluates the technological options for the heat source, the radiator and the PV cell for a TPV system. The optical control in terms of the angular, spatial and in particular spectral radiation distributions in cavities is identified as a specific factor for TPV conversion and critical for a system design. The impact of simultaneous radiation suppression above and below the PV cell bandgap on an ultimate efficiency level is examined. This research focuses on fused silica (SiO2) in TPV cavities and examines the aspects of radiation guidance by total internal reflection and spectral control using coupled radiative and conductive heat transfer. Finite volume modelling and experimental work have examined the radiator-glass-air-PV cell arrangement up to a SiO2 thickness of 20 cm. Both show that the efficiency improves for an increased SiO2 thickness. Finally, the novel concept of a TPV cavity consisting of a solid dielectric medium is assessed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modelling of grid connected geographically dispersed PV systems for power system studies

The growth of the photovoltaic market indicates that in the near future PV electricity generation may rise to a significant power source. As the proportion of electric power generated from PV systems becomes significant, the effect of these sources on transmission and distribution networks must be considered. This research work has investigated suitable representations of the PV resource and the output power of dispersed PV systems to study the effects of large-scale deployment of PV systems on the grid operation. The representation of solar radiation is very important since this dictates the output power of PV systems. In this work, the simple and reliable Markov Transition Matrix (MTM) method was selected to generate synthetic horizontal solar radiation data. A single MTM was developed to generate half-hour horizontal solar radiation data for different locations in the UK. Large-scale inclusion of PV systems in the UK electricity supply is expected to take the form of a large number of small, geographically dispersed building integrated PV systems. The study also developed a detailed PV cluster model to represent these dispersed PV systems. The variation of PV output power may impact the demand and generation balance on the network requiring additional reserve generation to ensure the system security. In this work, the variation of PV output power and the impact on the reserve requirement was analysed for different penetration levels. This is also the first study to analyse the correlation of solar radiation for different locations in the UK in regard to the impact on reserve requirements. Using data from three locations and according to the National Grid Company (NGC) requirements, it was found that PV capacities of 3750 MW could be added to the present network without additional reserve requirements. The additional reserve required is not on the basis of "MW of reserve per MW of PV capacity". Rather it is based on the aggregation of load demand and of PV output from all regions. The reduction in the reserve requirement by forecasting the weather profile of the day was also illustrated. In this case, a PV capacity of 22,500 MW, which can generate a little over 5% of the UK electricity demand, can be added with minimal increase in system cost. Therefore, the variation of PV output power is unlikely to be a threat to the system security.EThOS - Electronic Theses Online ServiceEngineering and Physical Sciences Research CouncilGBUnited Kingdo

The Effect of Distribution Network on the Annual Energy Yield and Economic Performance of Residential PV Systems under High Penetration

Technological advances, environmental awareness and, in several countries (including the UK), financial incentives lead to the adoption of PV (photovoltaic) systems. Economic viability, an important consideration for investment in residential PV, is dependent on the annual energy yield which is affected by distribution network based factors such as point of connection to network, network hosting capacity, load profiles etc. in addition to the climate of the location. A computational algorithm easy on resources is developed in this work to evaluate the effects of distribution network on the annual energy yield of residential PV systems under scenarios of increasing PV penetration. A case study was conducted for residential PV systems in Newcastle upon Tyne with a generic UK distribution network model. Results identified penetration levels at which PV generation curtailment would occur as a consequence of network voltage rise beyond grid limits and the variation in the percentage of annual energy yield curtailed among the systems connected to the network. The volatility of economic performance of the systems depending on its location within the network is also analysed. The study also looked at the impact of the resolution of PV generation profiles on energy yield estimates and consequently economic performance

Progress on the modernisation of the European PV system monitoring guidelines

ABSTRACT: In the context of a rapid development of the PV market, both in terms of capacity and the type of applications, the EC-funded Integrated Project PERFORMANCE is developing a modernised set of guidelines for the monitoring of PV system performance. The completed guidelines will be easily accessible for all interested parties, from system designers to system users and/or financiers, and will provide guidance on both the measurement of PV systems and the analysis of their performance. This paper discusses progress on the development of the web-based guidelines package, including the approach to allow custom guidelines to be generated for a wide range of users, the development of a failure modes effects analysis tailored to the monitoring process and the opportunity for industry input to the final development phase