- what states likely have the most solar installations (think sunny places like Florida, Texas, New Mexico, Arizona, Nevada and California)
- you might want to look into what companies make the equipment or the kits. They could be in a different state because it's cheaper to have their factory, warehouse or HQ there.
- there could be jobs in either of the places above (i.e. there could be jobs working with customers and installers locally are installing the product, but there are also often engineers that work elsewhere designing, approving the components and basic design packages that get shipped out)
- check out job boards and look for the companies that are hiring the most