Clivemy, that sounds workable as an approach which university departments could appreciate.  I could see a few professors encouraging their students to take part, for instance.  (A different but slightly analogous contest happened when I was in school, in one engineering class where there was an extra credit contest, with an external sponsor, to come up with the best way of transferring irrigation water in a remote South American village).

One concern would be ensuring potential participants know that what is being offered has much value, since a given amount of XEL won't mean much if not knowing what XEL is worth.  But that is easily solvable, if promotional communications mention what XEL is equivalent to at the time.