Performance Analysis and Degradation of a Large Fleet of PV Systems

Abstract

This article presents an initial performance analysis of a database of photovoltaic (PV) system performance time series collected within the European funded COST Action PEARL PV. The database contains monitoring data of over 8400 PV systems with accompanying metadata. The PV plants are small residential systems, primarily installed in Europe, with a high density in Belgium. In this initial study, the annual average performance ratio, the annual energy yield, and the performance loss rate of the systems are determined and evaluated. The systems have an average lifetime of 30.5 months. The annual mean performance ratio across all systems is 76.7% and the average yield is 954.9 kWh/kWp per year. The performance loss rate is calculated using three different statistical approaches and one irradiance data source. Average performance losses between −0.74%/year and −0.86%/year are calculated depending on the used approach. Furthermore, certain weather-dependent correlations are detected, such as decreasing performance ratio and increasing yield values with increasing irradiation. This study is a stepping-stone for further populating the present database, lessons learnt for handling large amounts of PV performance data, and carrying out performance studies of PV system fleets installed across Europe.

Photovoltaic fleet degradation insights

“…Investigations of a large number of modules and systems providing a general overview of the state of the industry in a particular location are difficult to do but have seen an increased interest. [6][7][8][9] Because it takes several years to accumulate high-quality data, it is important to remember that studies on PLRs or curves only provide a temporary glimpse into the state of systems and may be subject to change. In this study, we use the large database from the PV Fleet initiative to investigate performance loss for thousands of systems across the United States and provide insights to PV stakeholders.…”

“…Valuable insights from literature can be glimpsed, but the investigated products tend to be older and the variety in technology and location may be limited. Investigations of a large number of modules and systems providing a general overview of the state of the industry in a particular location are difficult to do but have seen an increased interest 6–9 . Because it takes several years to accumulate high‐quality data, it is important to remember that studies on PLRs or curves only provide a temporary glimpse into the state of systems and may be subject to change.…”

Accurate Demand Forecasting: A Flexible and Balanced Electric Power Production Big Data Virtualization Based on Photovoltaic Power Plant

“…Similar studies for global PV systems were conducted [13][14][15][16], including some of the European systems [17][18][19]. The performance evaluation results obtained by analyzing a huge volume of datasets in those data banks displayed a global picture of the PV systems around the world, especially for small-sized PV installations that are for residential use [2].…”

“…The number of samples that would produce a statistically meaningful result is considered to be 100 [4,5] so that the results obtained for samples exceeding this number will be treated in the same way, whereas a group of monitoring data collected from 100 PV systems is assumed to be less significant, and therefore, each system should be analyzed independently. Wider confidence levels and higher risk of errors in hypothesis testing can be expected with small sample sizes [2].…”

“…Although the Republic of Korea (ROK) is converting various types of energy sources into electric power through thermal/hydroelectric/nuclear power generation, their government is pushing ahead with a policy to reduce the use of nuclear energy due to its explicit/implied risks while trying to secure alternative energy sources at the same time to compensate for the reduction in the total energy supply. The currently available alternatives include existing thermal power generation that uses energy sources that are expected to deplete in the near future or new and renewable energy-based power generation, which still offers quite a low level of efficiency but that is able to provide power indefinitely [2][3][4].…”