Energy systems and infrastructure are the bridges between energy demand and energy supply. Energy systems – including storage, digitalisation, sector coupling, demand-side management and regional interconnections – enable energy to be efficiently managed and transported where needed. This is particularly critical considering the record growth of solar photovoltaics and wind power generation documented in the recently launched Supply Module of the Renewables 2023 Global Status Report Collection. Like any solid bridge, energy systems and infrastructure require forward thinking, political vision, robust planning and substantial upfront investments. This module focuses on the intricacies of ensuring system inertia, the role of forecasting techniques, managing grid congestion and others. It also looks at the pivotal role of energy policies in improving grid quality and reliability, as well as the need for energy storage capacity and regional integration of energy systems. Countries investing in national and regional energy systems and infrastructure have achieved higher levels of renewable energy penetration compared to those that have not. As we celebrate the recent achievements in renewable energy and take stock of the road ahead, it is essential to understand the central roles of energy systems, infrastructure and parallel investments in achieving extensive deployment of renewables. I want to thank the REN21 team, the authors, special advisors and contributors who have given their expertise and time in producing this module. I trust that this module will provide the necessary insights and data to empower policy makers, industry leaders and stakeholders to fast-track the energy transition with renewables. Sincerely, Rana Adib Executive Director, REN21