A parametric method using vernacular urban block typologies for investigating interactions between solar energy use and urban design

Zhongming Shi,Jimeno A Fonseca,Arno Schlueter

doi:10.1016/j.renene.2020.10.067

Abstract

Building geometries strongly constrain the on-site solar energy use. In this work, solar energy use is measured by solar energy penetration and capital costs for the photovoltaic panel installations. This work provides a novel typological method for investigating interactions between solar energy use and urban design. Compared to other studies using typological methods, this work uses a typological method that highlights both computational efficiency and relevance to the vernacular contexts. Typical vernacular block typologies are formulated using a case study of built urban form featuring various combinations of block dimensions, building patterns, floor area ratios, and site coverage. We develop the Urban Block Generator, a tool to parametrically model such block typologies in Rhino/Grasshopper. We assess the solar energy penetration and the capital costs for these block typologies using the Urban Block Generator and the City Energy Analyst, an urban energy modeling and simulation program. We demonstrate this workflow on a case study in Singapore formulating 18 vernacular block typologies. The results are discussed and interpreted into urban design options and suggestions on various urban design parameters for different main driving forces, either maximizing the solar energy use or achieving a certain floor area ratio.

Highlights

Cities are responsible for approximately 75% of the primary energy use and 60% of the greenhouse emissions [1]
Assessing the block typologies We propose a method for assessing the solar energy penetrations and the capital costs for each block typology using a diverse surrounding context
They are implemented as a tool on the Grasshopper/Rhinoceros platform, named the Urban Block Generator. It helps generate building geometries of early-stage urban design for greenfield projects. These building geometries are used for energy simulations with the City Energy Analyst to assess their solar energy penetration and capital costs

Summary

Introduction

Cities are responsible for approximately 75% of the primary energy use and 60% of the greenhouse emissions [1]. At the early-stage, such analyses face a challenge that there is a lack of designs of building geometries Their envelope surfaces and their mutual shading effects are directly associated with on-site solar energy harvesting, especially in a dense urban setting. We provide a typological method for investigating interactions between solar energy use and early-stage urban design. The first category uses generic building patterns [22e25] This method usually repeats the targeted geometries of the study to create the surrounding contexts, as in Fig. 1 (a). The second category uses built urban forms for both the targeted and the surrounding geometries, as in Fig. 1 (b) [8,9,26e31]. Similar to the generic methods, it uses simplified geometries It only uses those featuring or representing vernacular urban forms and building regulations. The third category repeats the targeted geometries to create the surrounding contexts, as in Fig. 1 (c)

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