Smart grids are an impactful emerging technology in the Information and Communication Technology (ICT) field. Different from prior research, the present study aims at providing a comprehensive overview of the smart grid domain by disentangling the technology structure, depicting the technology landscape, identifying the innovation trends, and highlighting the major players. Specifically, using a patent co-classification analysis and examining the U.S. patents granted from 2010 to 2017, we identified three different technology structures: (1) core structure, (2) supportive structure, and (3) complementary structure. The last two can be conceived as layers that encompass on and gravitate around the core technology of the smart grid. The framework provided can offer insights into a deeper understanding of entry dynamics and standards emergence.