The International Solar Alliance (ISA) is a treaty-based inter-governmental organization and an action-oriented collaborative platform for the increased deployment of solar energy technologies. It was jointly conceived by India and France and formally launched on November 30, 2015, during the 21st Conference of Parties (COP21) to the UNFCCC in Paris. The ISA was created to mobilize collective action against climate change and remove obstacles to solar energy deployment, initially focusing on solar-resource-rich countries. Notably, the ISA is the first international organization to have its headquarters in India, located in Gurugram, Haryana.
The ISA's mechanism is guided by its 'Towards 1000' strategy, which aims to mobilize US$1 trillion in solar investments, install 1,000 gigawatts (GW) of solar capacity, and provide energy access to 1 billion people by 2030. It works through a Catalytic Finance Hub to mobilize blended finance and reduce the cost of capital for solar projects. It also promotes policy harmonization, such as through template contracts like "Open Solar Contracts", to simplify legal agreements and reduce transaction costs. The ISA is closely connected to the concept of "One Sun, One World, One Grid" (OSOWOG), a vision for a global energy system.
A significant recent change occurred in January 2021, when the ISA's Framework Agreement was amended to universalize membership eligibility, extending it from the initial focus on countries between the Tropics of Cancer and Capricorn to all United Nations member states. This change broadened its reach while maintaining its core mission of accelerating global solar deployment.