Foreword for the special section on sustainable power network planning

OVER the past decade, renewable energy has seen rapid development across the world with a total installed capacity of wind generation reaching 435 GW and photovoltaic 223 GW by the end of 2015. This trend is likely to accelerate in the foreseeable future, especially in China where the government has committed to the goal of clean energy contributing 20% of all energy consumption by 2030. Worldwide, renewable energy is increasingly becoming a major or dominant power generation source in traditionally fossil fuel dominated power systems. However, a high penetration of large-scale renewable power, due to its inherent variability and intermittency, will have a profound impact on all aspects of power systems, including planning, operation, generation, transmission, distribution and end user consumption. Sustainable power network planning aims at planning and designing a future network with a high level of renewable energy that is secure, affordable and reliable against a wide spectrum of uncertainties.