While Charlotte, N.C., is perhaps best known as a financial center, with big institutions like Bank of America and Wells Fargo dominating the skyline, the area is also a major energy hub. The region is home to more than 260 companies and nearly 28,000 workers that are tied directly to the energy sector, including Charlotte-based Duke Energy. Moreover, the region is developing a growing number of clean energy initiatives, and the state has implemented legislature that requires investor-owned utilities to generate 12.5 percent of their retail sales from renewable energy by 2021.