Some examples of how development co-operation providers are supporting the enabling environment for green investment in a country are illustrated in Box 2.2, research on this area of development co-operation support is ongoing (e.g. DCED Green Growth Working Group). The need for clean infrastructure, particularly solar and wind energy, and the potential for energy efficiency and technological innovation, provide entry points for private sector participation. Increasing demand for environmental services, such as waste and water management, also create opportunities for private investment, both foreign and domestic.