Quantitative sustainability modeling and assessment of US transportation energy systems, including case studies of alternate biofuel production and orbital transportation systems

Abstract

This research identified and assessed the sustainability risks of existing and emerging US transportation energy systems using quantitative sustainability engineering methodologies including life cycle assessment (LCA) and growth curve modeling. A macro-level analysis of US energy and transportation system dynamics was performed to identify system level sustainability impacts and risks. Two case studies were explored with the aim of identifying where policy and technological solutions could improve sustainability: alternative biofuel production and orbital transportation systems. The findings demonstrated that logistic growth curve modeling fixed condition forecasts can be used to evaluate macro US energy and biofuel production systems. The macro-level assessment suggested the need for significant efforts to ensure the sustainable development of US energy and fuel production through 2040 with appropriate policy support employing such sustainability methodologies. Findings regarding alternate biofuel production demonstrated that biofuels cultivated on marginal lands could noticeably contribute to increased sustainable fuel production in the US. The environmental impact assessment results for biofuel cultivation on abandoned mine land showed the modeled land amelioration and biofuel production process produced significantly less environmental impact than other commonly employed reclamation processes. US biofuel policy would benefit from including such biofuel production on marginal lands in production goals. Furthermore, this research included the first LCA of orbital transportation systems including a proposed space elevator with comparison to existing terrestrial megaprojects. Results showed that the space elevator has the potential to be an environmentally- and cost-effective means for payload delivery to Earth’s orbits, and that reusable rocket launch infrastructure such as with the Falcon Heavy significantly reduced environmental and cost impacts. These quantitative sustainability models, assessment, and case studies revealed them to be a robust and versatile set of tools and that sustainable engineering can shed light on potential paths to a more sustainable future.