The 1914-built three-masted steel bark Statsraad Lehmkuhl is the oldest of the large square riggers still in operation today. Photo from Rolls-Royce
MarineLink is reporting that the Norwegian sail training bark Statsraad Lehmkuhl (which looks a lot like the Eagle) will be equipped with a bank of Batteries for both propulsion and ship’s service power. Electricity, to be stored in the batteries, can come from diesel generators, shore power, or be generated by the action of the ship’s propeller when being dragged through the sea under sail.
Chuck Hill's CG Blog 
To me it sounds (no pun intended) is to Eliminate as Much a the Diesel Sound as possible. Make “Her” sound like a Sailing Ship, even if movement is performed using electric propulsion…
Europeans have gotten very sensitive to air pollution in ports. Seeing more LNG and battery powered vessels all the time.
How’s the Vessel to be fueled? If “Still” Diesel, than nothing has changed. With the exception of “Hybrid Propulsion”…
I think that is correct.
Hybrid plus Battery
The UK RRS Sir David Attenborough, a15,000T, for research in Antarctic, uses hybrid propulsion with 18MW Bergen DG’s and 11MW Alconz motors plus SAFT batteries with Li-ion high power cells to provide a combined 1450 kWh capacity at maximum voltage of 1011V allowing near silent operation when necessary and power in emergencies. RR Marine AS claiming 5 MW peak effect battery capacity, guessing for short period batteries can withstand stressing to a factor of 3.4 from normal power draw (5/1.45) and recover, impressed if understanding correctly.