Performance Ratio Analysis Based on Energy Production for Large-Scale Solar Plant

Abstract

This paper presents an industrial approach to assess the performance of large-scale solar plants (LSSPs) has been developed using a novel performance ratio (PR) formula model based on energy production. The PR is an important quality indicator used for the LSSP projects with a nominal installed capacity of 20 MWdc upward. When solar power plants are put into operation on the national grid, the PR can be used as a performance indicator to ensure the energy guarantee and the plant’s efficiency required to guarantee a level of performance. Then, PR gives the real face of the plant’s efficiency. This is not an easy task because it has no constant value over the years due to the effective incident global irradiation (GlobInc) value always not being available. For this purpose, the proposed PR formula model is used to compute the correct performance guarantee of the grid-connected 100MWdc-LSSP in Pakistan’s Quaid-e-Azam Solar Park (QASP). The main purpose of this study is to incorporate a PR formula based on energy production evaluation to achieve the energy guarantee (excess energy, bonus energy, or energy shortfall) in LSSPs. The 1-year on-site plant data is utilized to investigate the plant’s performance energy inputs such as production, irradiance, PR, and the excess energy. Based on the actual annual energy output and irradiance of the plant, the following results are obtained: Actual PR is achieved at a higher level than the target benchmark, so no shortfall or liquefied damage (LD) is imposed due to excess energy. Thus, 100MWdc-LSSP’s power generation is found to be 5% higher than expected by using the theoretical calculations of PR. In FY (2018–2019), the system fed 0.34% higher PR, with an actual PR of 76.58% higher than the target PR of 76.24%, and extra energy of 710.72MWh produced, as well as bonus energy of 142,143.62 USD. The majority of LSSP projects are determined to be successfully operational and generate a significant amount of power, but they fail to meet the contractual requirements for energy guarantee because they use the incorrect PR formula and also fail to provide the desired energy to stakeholders owing to a poor theoretical assessment of the PR criteria based on energy production. As a result, solar power plants confront a great energy shortfall for many years to come.