Rural entrepreneurs are key drivers of new clean-energy technologies, particularly for household lighting and productive uses in small industry, agriculture and water supply. But few clean-energy industries exist, and the challenges of rural enterprise development and financing are large. New models of enterprise development and financing are needed, along with adoption of proven methods. In terms of development, clean energy - energy efficiency and renewable energy - can often provide substantial environmental improvements in addition to needed energy services. Deforestation from unsustainable wood fuel collection is a pressing problem in sub-Saharan nations, who will experience sever shortages by 2025. Indoor air pollution from the inefficient burning of wood, crop waste and dung causes an estimated two million premature deaths a year and is a leading cause of child mortality.