The ever-ebullient and publicity-friendly Elon Musk of electric car maker Tesla fame was reported by online organ Electrek (https://is.gd/axirol) in July this year as saying that electric aircraft would be put into use within five years. He already has a design for an electric vertical take-off and landing aircraft, in fact. But battery technology must improve, he adds, saying that Li-Ion batteries need to achieve a 400 Wh/kg energy density in order for batteries to best kerosene and make his electric aircraft viable.
Today, high cycling battery cells are achieving about 300 Wh/kg of energy density, the article adds. It should be said that Musk has not yet said that his company is going to produce such a plane, however, or revealed much detail about the design. It is likely that it is one of the many small, personal or taxi-type electric aircraft currently being developed. According to an article on the Royal Aeronautical Society’s website published in December 2017 (https:// is.gd/elitun), there were some 300+ start-ups and established companies active in that area even then.