Thank you for fleshing out your plan for me.
I think submitting an essay in the form of a post would be a requisite. One way to do this is to have a "open window for submission" between say the first and 30th of a given month. At the end of it you would post all essays with a special tag and encourage voting. This would give the community a chance to vote on the student would be allowed to keep whatever SD their post generates but the board of trustees or directions of judging panel would 1) keep the SP, and 2) ultimately decide upon the best essay to receive the scholarship.
Funding the student for two years seems like a long shot. The right student should be able to fund themselves using this platform better than the scholarship would. You'd need significant SP to make that work, better it stay in the account to assist with generating rewards for round two.