Policy-driven institutions such as national development banks (NDBs) and national green funds (NGFs) attract a growing interest to provide grants, credit-enhancement instruments or lend directly to project proponents in specific green sectors, with billions of dollars allocated by governments to support these interventions. As part of ongoing efforts to better understand their comparative effectiveness to deepen national financial systems, the paper discusses the role of NGFs in catalysing institutional innovations and facilitating access to long-term affordable finance for green, low carbon and climate resilient investment. It argues that the key added value of NGFs might rest in their capacity to foster institutional innovations and partner with other financial and regulatory institutions to increase the diversity and depth of local financial markets in order to enhance the domestic supply of green finance."