Determining Air Quality and Greenhouse Gas Impacts of Hydrogen Infrastructure and Fuel Cell Vehicles

Scott Samuelsen,Donald Dabdub,Shane Stephens-Romero,Marc Carreras-Sospedra,Jacob Brouwer

doi:10.1021/es901515y

Abstract

Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario).

Highlights

Future transport of people and goods will be constrained by limits on criteria pollutant emissions, scarcity of hydrocarbon fossil fuel resources, and greenhouse gas (GHG) regulation [1]
Current interest in reducing greenhouse gases and improving urban air quality coupled with readiness to demonstrate and deploy alternative transportation fuel infrastructure and vehicle technologies has created a need for the capability to simulate the environmental impacts of potentially realistic energy scenarios that are simulated at a higher resolution and with the option of integrating and comparing a variety of fuel, energy, and vehicle strategies
Results obtained in this study for the South Coast Air Basin of California (SoCAB) establish that [1] a significant adoption of hydrogen infrastructure with hydrogen fuel cell vehicles (HFCVs) in the year 2060 will substantially improve urban air quality in the SoCAB concomitant with a reduction in WTW GHG emissions from the passenger vehicle fleet, and [2] a renewable energy emphasis (Scenario HR) on hydrogen infrastructure deployment produces localized air quality benefits that surpass those of a hydrogen infrastructure scenario with more fossil fuel use (Scenario HF)

Summary

Introduction

Future transport of people and goods will be constrained by limits on criteria pollutant emissions, scarcity of hydrocarbon fossil fuel resources, and greenhouse gas (GHG) regulation [1]. Studies widely agree that the implementation of hydrogen infrastructure will reduce air pollutant emissions from the transportation sector [3,4,5,6,7], the extent to which air quality in an urban airshed will be affected by these reductions is a more complex matter than quantifying emissions. Et al (2007), (2008) broadly applied an empirical air quality formula to emissions reductions from hydrogen infrastructure, but neglected to simulate detailed atmospheric chemistry and transport mechanisms that lead to the formation of secondary pollutants [6, 8]. This study compares the air quality impacts of fully integrated hydrogen infrastructure scenarios in an urban airshed by introducing a spatially and temporally resolved scenario development and analysis methodology. Previous efforts to model GHG impacts of hydrogen infrastructure deployment have included only discrete production and delivery strategies for the provision hydrogen fuel at a regional or national scale [3,4,5,6,7,8]

Methods

Results

Discussion

Conclusion