Ewing told an investment conference in Belfast a "strong and diverse" Scottish economy will be an asset for neighboring countries if voters say yes to a late 2014 referendum for independence.
The Irish-Scottish Links on Energy Study, a joint effort examining offshore interconnected electricity, and other projects like it "can help Northern Ireland, Ireland and Scotland deliver our huge off-shore renewable energy potential including wind, wave and tidal," he said.
Ewing said Ireland last year received $1.3 billion worth of Scottish exports and "so much more" would come through independence.
Scotland has one of the most ambitious renewable energy programs in the world. It was cleared this week to develop a research center for offshore wind technology after U.S. real estate mogul Donald Trump lost a challenge over land issues tied to his nearby golf course.
Ewing said independence isn't about turning away from its nearest neighbors, but "about being treated as equals and working together."