NASA did a study in about 2010 of electric aircraft where they concluded that battery energy density needed to be just 3 times the current state of the technolo

NASA did a study in about 2010 of electric aircraft where they concluded that battery energy density needed to be just 3 times the current state of the technology before it would become economically viable. [1] [1]https://ntrs.nasa.gov/search.jsp?R=20110011311 https://ntrs.nasa.gov/search.jsp?R=20110011311 (this is not the actual paper I remember but it is very similar)