A civil engineer with a background in structural engineering/dynamics would certainly find work. Site development would be one area of involvement for CE's. Much of the work however probably involves mechanical and electrical engineers.
One should look into the technology being employed in solar (e.g., photovoltaic and concentrated solar) or in wind to see how one's experience/expertise fits with the technology.
In power systems, civil engineers design the infrastructure such as buildings/structures and site features, while mechanical engineers focus more on the power production and conversion systems. Of course, they interface and there is overlap in engineering functions.