On the Energy Sustainability of Active and Passive Building-Integrated Technologies in the Context of Changing Climate for a Tropical Coastal City

Meso America and the Caribbean regions are sensitive to global climate change. Past studies have demonstrated that Caribbean Sea surface temperature have been rising at an alarming rate of 0.020C/year. The effect of rising sea surface temperatures are reflected in the rise in 2m air temperature consequently increasing extreme heat events over the Caribbean. The rise in extreme temperature event increases human discomfort index and air conditioning demands putting both the population and energy infrastructure at higher risk of vulnerability. This vulnerability is amplified in compact cities where anthropogenic heat removal from built environment increases the temperature of the urban canyon thereby enhancing discomfort index and energy demands. Although there has been some work done on mitigating energy demands during extreme heat events, these studies are focused mostly on the building scale, where the two-way interaction between climate and buildings is missing. Thus, the effect of these technologies on the micro climate and energy demand on a scale of a city is still unknown, so is the assessment of their mitigating impacts under future climate conditions. Such an understanding is important in developing next generation sustainable active and passive building integrated energy technologies that improves human comfort, mitigate peak demands and produces power on site in the midst of a changing climate. In this paper, we develop and describe a new methodology for quantifying human discomfort index and peak air conditioning demands for different passive and active building integrated technologies. The goal of the study is to identify different technological scenarios that promote environmental and energy sustainability of the urban environment of tropical coastal cities with San Juan, Puerto Rico as a case study. The role of potential scenarios for improving the overall comfort, UHI and reducing air conditioning demand is explored for future climate change scenarios. We anticipate that the results of this paper will generate new knowledge and support decisions of policy maker on implementing different technologies for coastal tropical cities.