PHILADELPHIA—ACE USA said Tuesday that it has developed a renewable energy underwriting unit as part of its casualty risk division in response to the growth of the renewable energy sector.

ACE USA, the Philadelphia-based retail insurance division of ACE Group of Cos., established the specialized underwriting unit to address the demand for traditional and nontraditional energy sources and solutions for the market.

The unit will provide energy-related products and services, the insurer said in a statement, including options for property, casualty and errors and omissions insurance.

Darren Small, who has been named vp and national renewable energy underwriting manager, is leading the unit. Mr. Small, who is based in Chicago, joined ACE USA from Chubb Corp., where he was assistant vp and worldwide biofuels underwriting manager.