Analysis of net zero energy buildings and communities that strategically integrate transportation energy

Abstract

The limited oil supplies, rising fuel prices and greenhouse gas (GHG) emissions, have heightened the demand for alternative energy sources, especially in transportation and residential sectors. The rise of electric vehicles (EVs), plug-in hybrid vehicles (PHEVs), and fuel cell vehicles (FCVs) have reduced dependence on oil and emissions. Governments and researchers are exploring net zero energy building/community (NZEB/C) options to meet GHG emission mandates for new and existing dwellings. This study evaluates the benefits of integrating transportation energy with a NZEB via the electric grid, focusing on EVs, PHEVs, and FCVs. The study analyzes energy performance in a NZEB/C and transportation sector, aiming to achieve net zero energy status in both new and existing communities. The motivation of this study is to address the limited research on EV, PHEV integration with NZEBs, particularly on larger NZEB/Cs and FCV side. A methodology was developed to analyze communities with various vehicles simultaneously, addressing issues with software programs lacking databases for alternative fuels. MATLAB was used for simultaneous energy analysis and transportation integration, reducing computational time and eliminating the need for multiple programs. This analysis, unrestricted to specific software programs, fills the gap in analyzing integration of transportation energy within a NZEB/C for potential benefits. A 1-D thermal resistance network was developed, enabling faster energy usage calculations and better understanding of energy flow within a house/building. The study revealed, discharge of energy from EV battery, PHEV and FCV energy contributions via their hydrogen and biogas fuel tanks accounted for 10%, 16%, and 25%, respectively, of the community's energy consumption. As the communities considered are expanded to larger sizes, energy discharge and contribution decreases due to vehicle storage limitations and the increased presence of smaller vehicles in the analysis. The PHEV converted to operate on biogas is an attractive type of vehicle for transportation energy integration due to its lower cost compared to gasoline and diesel fuels. However, it is less environmentally friendly compared to EVs and FCVs due to the emission produced using biogas. The FCV's economic benefits determined to be achieved when the cost of hydrogen fuel was less than 4.95 CAD/kg.