Yeah, there really is no reason not to put one in up in MN - all you have to do is make sure you have the right # of tons... If you're putting in a vertical loop system, that just means more wells. If you're putting in a trenched system, you have to dig deeper (I imagine you have very few of these in MN).
As for your rebate, I'm assuming you meant 2% of the cost, right? .02% would mean that the system cost you about $1.25 million. :)
How many wells or feet of trench did they put in for the MN system ? Bet its not in Duluth. That rock is hard stuff.