Were the peels very aromatic to begin with? Or were they generic flavorless/tasteless oranges for the grocery store. Not every orange/citrus variety is going to be aromantic, and will impart little if any aroma and flavor to the beer. That's why seville orange are very popular, and is the dry peel you get at the homebrewshop.
Hell half the time the oranges from the grocery are coated with a waxy substance so the peel is all shiny. That's going to limit the amount aroma. You really have to smell the oranges, and buy them based on aroma and not by looks, in fact some of the most aromatic are the ugliest ones, even still green.
Honestly I have had very little luck with grocery store oranges, and tend to just buy the dry stuff from the lhbs, it's easier than hunting down Seville. You may want to try fruit markets rather than grocery stores, they may have better varieties than the grown for grocery store types. Like anything fruit grown commercially for grocery stores are meant to look pretty, be shelf stable and bear little resemmblance to the orange growing in someone's backyard in Florida.
Get ahold of radical brewing by Randy Mosher, he has a great discussion on using citrus in beers. It's really helpful.
Zesting is a good idea, BUT zesting a crappy odorless orange is still going to result in odorless beer. You have to start with the fruit itself.
(besides lemonade, of course).
