Using Aerosol Optical Depth to Enhance Prediction of Solar PV Performance in Tropical Climates: Case Study—Barbados

In its 2019-2030 energy policy, the Government of Barbados has developed a target of making the small island developing state derive 100% of its energy needs from renewable sources by 2030. Energy generated from solar photovoltaic (PV) installations has already burgeoned into a verified industry. As of 2017 approximately 10% is included in the total energy mix in Barbados. Currently, installed capacity has increased by approximately 700% in the last 5 years.

However, local operating conditions vary from laboratory test conditions used to determine power ratings of the PV modules and hence the systems. Additionally, there are other environmental factors that are not used during controlled laboratory testing and rating. The literature is filled with performance of the major factors of temperature and irradiance and how they will affect performance, but other factors should also be quantified. One such environmental factor is dust accumulation as a result of atmospheric particulates.

PV performance studies on this effect in tropical regions is sparse. However, the high humidity of the region will increase accumulation rates onto surfaces. In addition, with Barbados being the most easterly island in the Caribbean, particulate matter in the atmosphere at certain times of year consists of a significant amount of Saharan dust. As the solar PV generation capacity continues to increase in Barbados, research into the effect of the region’s unique environment on PV performance can be used to tailor PV system installation design and maintenance by location and by technology.

This study will examine the effect of mass concentration as a function of accumulation rates on module surfaces and hence the effect on module power. It is the intention of the researchers for this study to be applied within the region where local mass concentration data may not be readily available. We will therefore supplement this deficiency, by obtaining a relationship between readily available satellite-based and/or surface aerosol optical depth (AOD) data and mass concentration. Therefore, the AOD may be used as a proxy to determine the effect of mass concentration on PV performance.

Power obtained from four commercially available photovoltaic modules installed at Deebles Point (1.6 km from local mass concentration site Ragged Point) were obtained. This data is analysed along with satellite AOD and mass concentration data to examine the PV performance during periods of Saharan dust, wet season and dry season.