[bunderbunder]

No, I'm trying to focus on the forest instead of the trees.

It's true, pennies are a horrible waste. It costs almost $0.02 to make one, and nobody even likes them very much, but the mint still churns out billions of the things ever year. That should probably stop.

But overall, coinage is a tiny fraction of the overall dollar economy. And Bitcoin isn't really comparable to coinage, anyway, since BTC is not a fast, convenient, anonymous, peer-to-peer mechanism for exchange that's appropriate for use in small transactions. Compared on that level, BTC seems sub-optimal long before we start worrying about details like energy efficiency of production.

What BTC really compares to is a currency in general, such as the dollar. There BTC at least has a chance of comparing on a vaguely level playing field. And at that scale, pennies are insignificant.