Blakesley, J C; Koutsourakis, G; Parsons, D E; Mica, N A; Balasubramanyam, S; Russell, M G (2023) Sourcing albedo data for bifacial PV systems in complex landscapes. Solar Energy, 266. 112144

Preview

Text eid9975.pdf - Published Version Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (2MB) | Preview

Abstract

Bifacial photovoltaic (PV) systems harvest additional light reflected from the ground. The proportion of light reflected from the ground (albedo) is a critical parameter in estimating the expected performance of these systems. Such estimations are used in design and investment decisions before bifacial PV systems are built, and in identifying underperforming systems after they are built. It is important that albedo data for such an application available at the design and decision stage are accurate and relevant, and that the confidence in these data can be quantified. This work investigates the challenges of different albedo data sources for bifacial PV system applications and proposes solutions towards more reliable datasets. Satellite sources, such as the NASA Moderate Resolution Imaging Spectrometer (MODIS) products, provide data that can be used to model effective albedo anywhere in the world. Nevertheless, there are numerous sources of error that can add uncertainty in bifacial gain, reducing confidence in design choices and increasing financial risk. Especially for smaller sites (<~10 MW) located in varied landscapes, where the scaling error caused by the low spatial resolution of the MODIS satellites can be large. By analysing case studies in complex agricultural landscapes, we investigate the accuracy of different albedo measurement approaches. Monitoring stations with reference cells and pyranometers were deployed to validate satellite data but also to realise a site measurement campaign for albedo measurements. Since these sites are much smaller than the MODIS pixel, we have evaluated alternative approaches, such as the use of “typical landscapes” with adjustments for local latitude and weather, and a novel method of combining MODIS data with higher resolution satellites. The latter offers a practical solution with results in good agreement with the ground-based station. We also propose relevant albedometer configurations that account for spectral effects related to bifacial PV applications.

Item Type:	Article
Keywords:	Photovoltaic systems; Albedo; Bifacial photovoltaics; Yield modelling
Subjects:	Advanced Materials > Photovoltaics
Divisions:	Electromagnetic & Electrochemical Technologies
Identification number/DOI:	10.1016/j.solener.2023.112144
Last Modified:	27 Jun 2024 14:22
URI:	http://eprintspublications.npl.co.uk/id/eprint/9975

Actions (login required)

View Item