The Potential of Structural Batteries for Commuter Aircraft Hybridization

Abstract

Electric or hybrid electric propulsion systems have received a great deal of attention in recent years in various branches of transportation including aviation. Europe is committed to the ambitious goals of reducing CO2 emissions by 75%, NOx emissions by 90% and perceived noise by two-thirds by the year 2050 compared to the average new aircraft of the year 2000. The main barrier of the electric propulsion is bound to the battery limits in terms of energy and power densities, thus determining a relevant negative impact on payload or aircraft size. It is possible to design and fly an electrically propelled aircraft, as testified by some existing examples, both prototypical and production models, in the categories of ultralight and general aviation aircraft. A novel technology, which allows the electrification process toward heavier categories of aircraft, is constituted by structural batteries. These are similar in structure to carbon fiber composites, where the matrix features dielectric characteristics, making the structure capable of storing electric energy while retaining the capability to withstand mechanical loads. Despite that, it raises relevant issues concerning aircraft sizing procedures that need to be conceived considering the specific characteristics of such multifunctional technology. This research work aims to evaluate the potential benefits the structural batteries have on the fuel burn for a 11-seater commuter aircraft. According to the envisaged technologies (structural batteries), this work will focus on the determination of the best hybridization factors determining the energy requirements for the typical mission of a commuter aircraft.