Integrated power system planning is increasingly urgent as electricity supply transitions to cleaner sources, grids become increasingly intelligent, and demand becomes increasingly efficient and responsive. Recognizing the dramatic transformations underway in the global energy landscape, Clean Energy Ministerial leaders announced the launch of the 21st Century Power Partnership during the 3rd annual Clean Energy Ministerial in London, 25-26 April 2012. The Partnership represents an international public-private effort to promote large-scale deployment of energy efficiency and variable renewables through smart policies and programs that leverage smart grid solutions. Leaders from the Group of Eight (G8) industrialized nations endorsed the Partnership during the 38th annual G8 summit at Camp David, Maryland, USA. For more information about the partnership, email secretariat@cleanenergyministerial.org, or download the partnership's factsheet or slide deck.