An agricultural harvester includes a first power unit having a first rated output. The first power unit is couplable with a first primary load, including a threshing system load. A second power unit has a second rated output. The second power unit is couplable with a second primary load, including a propulsion load. A first motor/generator is mechanically coupled with the first power unit, and a second motor/generator is mechanically coupled with the second power unit. The second motor/generator is configured to electrically drive at least one external load. The second motor/generator and the first motor/generator are electrically coupled together.