Some Clarification On McCain's Cap

So here's what I think John McCain was referring to when he said that he opposes mandatory caps.

The reporter who asked McCain the question referred to a new European plan to impose mandatory targets on renewable energy. McCain opposes that, apparently. But what's confusing is that McCain answered by noting that he favored cap-n-trade instead, which is kind of like answering a question about your team's defensive line by referring to their offensive line. Defense: how you limit carbon emissions. Offense: how you promote renewable energy resources. Incidentally, and again, I write this without a detailed understanding of environmental policy: is it contradictory to tour the country and lecture us about reducing our dependence on foreign oil and on petroleum generally and then, at the same time, propose to allow states to find patches of oil (and natural gas) offshore and exploit them? What am I not getting here?