ohtheanxiety

You have my simpathies. I've been in a very similar field, and have seen grad students go through similar situations when their advisor left (though not as bad as you describe). Unfortunately, these types of academic communities are so small that his reputation could follow you for awhile. Hopefully, you will go on to work under someone else and can build a name for yourself. Have you thought about a related field like museum curating as an alternative?

Some of friends at Maxwell (Syracuse) got no funding initially, but were offered good funding for their second semester.

I would not get a PhD unless you are 100% certain that you want to become an academic researcher or professor in the sustainable energy field. A PhD in a science or engineering field is only really good for working in academia, and if you want to work in industry, an NGO, or government, you risk being percieved as simultaneoulsly both overqualified and having no experience (because you went from undergrad to grad school). The funding may be tempting but I would talk to folks at both programs to see what is a better fit for your long term goals. If you do go for the PhD program, I recommend finding someone who will be an understanding mentor (prof or other PhD) because the transition from undergrad to PhD level work/research can be quite overwhelming.