Simplified vector-based model tailored for urban-scale prediction of solar irradiance

Wei Liao, Yeonsook Heo, Shen Xu

Research output: Contribution to journalArticle

Abstract

This paper presents a simplified vector-based model on the basis of consideration of the urban context to effectively predict the solar potential of urban areas. The proposed model is based on vector-based methods without the use of ray trace and ray interception techniques, yet consists of new methods that suitably account for the nonuniform solar radiation of the sky, obstruction by urban surfaces, and reflection by urban surfaces in urban areas. The proposed model establishes three new methods to simplify the calculation in the context of urban applications: (1) a two-segment discretization model, (2) an edge angle detection obstruction model, and (3) a unified view-angle-based reflection model. The performance of the method was compared against the advanced daylight simulation program RADIANCE and measurements obtained from controlled experiments. The first comparison demonstrated the new method's provided flexible setting options for different resolution and prediction accuracy requirements and generated reasonably accurate predictions. The second comparison showed that the proposed model elicited average absolute differences of 6% and 5% compared to the actual measurements from the horizontal and vertical surfaces, respectively. In comparison with ray interception approach, the results showed that the proposed method required a much lower number of calculation iterations for detecting sky and building obstructions.

Original languageEnglish
Pages (from-to)566-586
Number of pages21
JournalSolar Energy
DOIs
Publication statusPublished - 2019 May 1
Externally publishedYes

Fingerprint

Daylight simulation
Solar radiation
Experiments

Keywords

  • Model validation
  • Simplified irradiance model
  • Urban-scale solar analysis

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

Cite this

Simplified vector-based model tailored for urban-scale prediction of solar irradiance. / Liao, Wei; Heo, Yeonsook; Xu, Shen.

In: Solar Energy, 01.05.2019, p. 566-586.

Research output: Contribution to journalArticle

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