A system can include a first generator configured to operate in a first speed range to produce a predetermined output characteristic, a second generator configured to operate at a second speed range different from the first speed range to produce the predetermined output characteristic, and a controller configured to activate the first generator at and/or above a first low activation speed and at and/or below a first high activation speed within the first speed range. The controller can be configured to activate the second generator at and/or above a second low activation speed within the second speed range. The controller can be configured to deactivate the first generator at and/or above a first high deactivation speed. The controller can be configured to deactivate the second generator at and/or below a second low deactivation speed.