I'm all for technology advancements and I hope they do get a workable aircraft up and going. ..but I'm getting tired of seeing merely 3d renderings every time someone boasts a new aircraft concept. I am waiting for actual pictures of the fuselage or engines.
As an "hybrid electric" fan aircraft it already is plug in; ie: those type of AC were always pluggable into an APU.
Plug-in electrics are enabling fossil fuel reliant vehicles to be super efficient on energy cost for shorter trips (esp during the cold starts of operation), and with aircraft that includes taxiing/ warmup.
In automotive, the non plug-in hybrid (early hybrid) was sometimes unable to come up with much better energyconsumption-rate than the non hybrid, .. which also depended a lot on driving style/purpose.
It's probably about time someone shows off this new innovative electric (unpluggable) technology for aviation purposes ... S A F E L Y .