# Emerging Fuels & Technologies

• Technological advances to meet clean air requirements
• These advances are changing the transportation landscape
• Much progress has been made in engine and aftertreatment technology
• In parallel, significant changes in fuels have happened
• Biofuels, alternative fuels including electric and natural gas are beginning to make strong inroads
• HEI has since its inception played a role in assessing new fuels and technologies. Recently, the variety of new fuels and technologies has been expanding at an unprecedented rate. Interest in such developments is high, especially given their implications for climate change, as well as conventional pollutant emission reductions. Of special interest to HEI is early identification of any potential impact of such developments, even while they may improve fuel efficiency and reduce greenhouse gases and traditional air emissions. HEI’s goal is to provide time-sensitive information about the full range of emissions and potential effects of new technologies and fuels that are being driven by concerns about climate, energy efficiency, and air quality.