There are a handful of partisan issues that are attached to renewable energy -- things like government funding (particularly through the stimulus bill), related allegations of favoritism and corruption, and climate change related regulation (cap & trade, etc.)

For example, a handful of "green energy" companies received stimulus funding and later went bankrupt; this has led to a great deal of partisan bickering over whether Obama is wasting taxpayer money, or whether we should leave it to private enterprise to figure out renewable energy. So while the concept of renewable energy is non-partisan, policies/discussion relating to funding and regulation of renewable energy can be quite partisan.

EDIT: http://www.people-press.org/2011/11/10/partisan-divide-over-... - see the chart near the bottom, titled "Partisan Gaps over Energy Policies".

I would say something similar is the case with respect to many other issues that sound non-partisan, like national parks -- peripheral issues like government funding and restrictions on private enterprise (logging on federal land?) can lead to a fairly significant partisan divide, even on issues that don't seem controversial.