It seems to me that most cases will be able to solve back for the internal link to the disad, and being that its their aff, probably have pretty strong evidence saying so. The only way that an aff wouldn't solve back for the terminal impact is if it is hyper-specific to the energy that the focus is being taken away from, in which case is extremely hard to outweigh generic advantages such as peak oil and warming. Plus, disad's like this (in my opinion) justify the internsic perm on the disad. The disad doesnt disprove the resolution, essentially the neg team still advocates another form of alternative energy just its a disad instead of a non-competitive counter plan, thus i think that the aff should be able to perm: do both. why not offer incentives to both forms of alternatives. And while the perm is technically intrinsic, non of the abuse stories for the intrinsic perm are relevant being that the neg is running it as a counter advocacy, its just like a counter plan perm: do the plan and the counterplan.