Over the coming decades, renewable energy sources, namely wind and solar, will need to play a larger role in our nation’s energy mix as we seek to lower greenhouse emissions and respond to renewable energy policies and the EPA’s Clean Power Plan. This thesis assesses the role of wider-area power system operations in the U.S. as a powerful solution in supporting the integration of these weather-driven, variable energy resources that pose substantial challenges to grid reliability. The expansion and integration of organized electricity markets and transmission networks over wider geographic areas can (1) help reduce net-variability in wind and solar power generation while improving reliability; (2) provide an outlet for over-generation while reducing curtailment; (3) improve resource utilization while enabling resource sharing and lowering electricity costs; and (4) enable low-cost pollution reduction by providing a cheap alternative to fossil-fuel generation. Through power industry assessment, case-study analyses, and modeling research using NOAA’s National Energy with Weather System Simulator to compare scenarios of regional expansion versus a nation power system, this paper evaluates the feasibility and role of wide-area expansion and integration in achieving higher levels of variable renewable energy than our current system is capable of supporting