Transmission resources have begun to figure more prominently in policy discussions as regions move to adopt more ambitious goals for clean energy supply from variable energy resources, such as wind and solar. The global body of experience related to expanding the transmission system to meet the need for renewables integration is growing. While there are common challenges and opportunities across all regions regarding physical system requirements, other features of the system vary greatly, such as market versus central ownership, operation, and dispatch and payment for services provided to the system. “Current Practices in Electricity Transmission” explores how seven regions have dealt with the opportunities and challenges of expanding the grid to serve public policy objectives for renewable energy. Many regions are making good progress and much can be learned from the variety of settings for this transmission work.