Determination of Performance and Degradation Rate of Grid Tied PV Systems in Islamabad, Pakistan Using Performance Ratio, Performance Index, Metered Kwh Methods and Economic Analysis /

Abstract

An increase in fossil fuel prices has propelled renewable energy to the forefront in the energy sector worldwide. Solar energy, being available widely across the whole world, an increase in the number of solar power plants has been seen. The solar photovoltaic industry is expanding at a rate that couldn’t even be dreamed of a few years ago. With the boom in the solar PV market in the last ten years, the need to identify the good performance modules from the bad has been an absolute necessity. Multiple new manufacturers (some with new PV technologies) are seeking to gain entry into the marketplace and current manufacturers are aggressively expanding their manufacturing lines. Production and test engineers want to be absolutely certain (as rapidly and inexpensively as possible) that their products will last for a long time (oftentimes, a minimum of 25 years’ lifetime is desired for photovoltaic systems). They also seek data to assure that changes in manufacturing processes and materials have not negatively impacted the longevity and reliability of the products. With such an increase, the importance of determining the performance and degradation rates of the components of such systems becomes important as slowly, the solar energy sector is ballooning into the Giga-watts scale. Thus three analyses have been seen to give good indications of the degradation: The Performance Ratio, the Performance Index and metered kWh method. Two commercial PV power plants from the hot-humid climate of Pakistan are analyzed to develop an understanding on the rate and trend of degradation seen by crystalline silicon PV modules these methods were validated from state-of-the-art systems. With the use of highly accurate performance models, the generated degradation rates may be used by the system owners to claim a warranty from PV module manufactures or other responsible parties. The two different linear degradation rates of both plants seem to suggest an improvement in the quality of modules that are being installed in newer systems. Based on this analysis, some recommendations have been made which are useful for the system suppliers, end users and educational systems & for policy making government organization. vi Also, the economic aspect and analysis of this particular plant is done using RETScreen. Using present tariff conditions in Pakistan and using the parameters such as NPV, IRR, etc. the payback period and cost benefit ratio is determined indicating towards a positive impact towards the economics of the power generated and supply chain into the grid. At Arizona State University, test labs offer testing services that apply more stress than the standard qualification tests as tools for differentiating products and for gaining additional confidence in long-term PV investments. While the value of a single international standard for comparative accelerated testing is extensively acknowledged, the development of a consensus is difficult. This thesis strives towards a visual inspection tool which records all damages and defects in PV modules which leads to failure and standard tests performing for durability and reliability of PV modules. A brief introduction of MTT kit, which can be used for different experiments and for building standalone system, is also included in this report. Along with the various tests done to test the PV modules, this report also discusses various modes of failures which can be seen in the field.