Government often plays a crucial and active role in funding technology innovation. Almost every major technical change in recent years can be traced back to state funding. A lack of state financing is a well-recognized barrier to the development of clean energy technologies. This is partially due to insufficient research on how governments can mobilize domestic finance for clean energy innovation, and on which policies are most effective in leveraging investments. My research explores how governments mobilize domestic finance for clean energy innovation based on four country cases: the United States, Germany, China, and India.