Yekang Ko

Urban Form and Residential Energy Use: A Review of Design Principles and Research Findings

The effect of urban form on residential energy use has attracted much research, but it may be difficult to grasp the conclusions of that research because of inconsistencies in scope and methods employed. This article reviews the literature on how urban form affects residential energy use, particularly energy for space-conditioning (heating and cooling). Climate-responsive design principles are examined first and linked to research on how several factors affect residential energy use: housing type, density (physical compactness and dwelling unit density), community layout (street orientation and building configuration), and planting and other surface coverage. The research on each of these factors is summarized under three categories: experiments, simulation modeling, and statistical analysis of empirical data. Finally, implications for future research are discussed and suggestions for planning are made.

The Effect of Urban Form and Residential Cooling Energy Use in Sacramento, California

The impact of urban form on residential space-conditioning energy use has been controversial in recent planning literature. This study empirically evaluates the association between urban form and residential energy use, focusing particularly on residential electricity use for space cooling in the City of Sacramento, California. We characterize urban form, property conditions, and demographic and socioeconomic characteristics by applying spatial metrics embedded within a geographic information system where LiDAR data effectively include each building and the surrounding vegetation. A statistical model is applied to assess the relationship between these explanatory variables and the estimated summer air-conditioning energy use. Controlling for other variables, higher population density, east—west street orientation, higher green space density, larger vegetation on the east, south, and especially the west sides of houses, appears to have statistically significant effects on reducing summer cooling energy use. This study quantifies the built environment impact on the energy demand of air conditioning and informs planners as they craft urban planning and design policies for energy conservation.

A CONFLICT OF GREENS: GREEN DEVELOPMENT VERSUS HABITAT PRESERVATION – THE CASE OF INCHEON, SOUTH KOREA

Boosting the economy in green ways is a goal for many nations, but not all agree on what “green” means; the efforts of the Republic of Korea (South Korea) include a range of policies under the framework of green growth, from a national stimulus plan to local city initiatives. In August 2008, President Lee Myung-bak proclaimed that “low-carbon green growth” (shortened to “green growth” here) would become the nation’s new vision for overcoming the challenges of climate change and a looming carbon-based energy crisis while still continuing economic growth. South Korea’s version of green growth is defined as “growth achieved by saving and using energy and resources efficiently to reduce climate change and damage to the by Yekang Ko, Derek K. Schubert, and Randolph T. Hester

Toward a solar city: Trade-offs between on-site solar energy potential and vehicle energy consumption in San Francisco, California

ABSTRACT This study demonstrates the trade-offs between vehicle energy consumption and on-site solar energy potential in a city landscape. While higher urban density may curb many of the problems associated with sprawl mainly by reducing vehicle travels and associated energy use, it can also limit on-site rooftop solar energy utilization due to more shade on rooftops in dense urban settings and less available rooftop area per person. Using travel survey, Geographic Information System (GIS) and Light Detection and Ranging (LiDAR) data, we estimated vehicle energy use and rooftop solar potential in the City of San Francisco as a case study and calculated possible offsetting effects between vehicle energy consumption and rooftop solar potential. Given the prevalence of gasoline-based vehicles and todays solar photovoltaic (PV) panel efficiency, vehicle energy use per capita appears to exceed energy generated by rooftop solar PVs per capita across all density ranges, especially in lower density environments. At the point when electric cars and advanced, highly efficient solar PV panels penetrate the market, the results change based on the combination of different technological options. A significant reduction of energy consumption can be achieved through the immediate and rapid spread of energy efficient technologies in vehicles and solar PVs along with the long-term effect from gradual urban densification.