Many countries, reflecting very different geographies, markets, and power systems, are successfully managing high levels of variable renewable energy on the electric grid, including that from wind and solar energy. This book documents the diverse approaches to effective integration of variable renewable energy among six countries: Australia (South Australia), Denmark, Germany, Ireland, Spain, and the United States (Colorado and Texas), and summarises policy best practices that energy ministers and other stakeholders can pursue to ensure that electricity markets and power systems can effectively co-evolve with increasing penetrations of variable renewable energy. There is no one-size fits all approach; each country has crafted its own combination of policies, market designs, and system operations to achieve the system reliability and flexibility needed to successfully integrate renewables. Notwithstanding this diversity, the approaches all coalesce around five strategic areas: lead public engagement, particularly for new transmission; co-ordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations. This book also underscores the value of countries sharing their experiences. The more diverse and robust the experience base from which a country can draw, the more likely that it will be able to implement an appropriate, optimised, and system-wide approach.