New Jersey utility Public Service Enterprise Group, facing state clean energy mandates and an economic imperative to shift its business to regulated assets, is seeking to exit its merchant fossil and solar generation business, while retaining its nuclear power plants and exploring a major expansion into offshore wind. PSEG announced Friday that it’s “exploring strategic alternatives” to its more than 6,750 megawatts of fossil generation in New Jersey, Connecticut, New York and Maryland, and its 467-megawatt Solar Source portfolio spread across 14 states.