Fenix International received a grant from the M4D Utilities Innovation Fund in December 2013 to scale up its pay-as-you-go solar home system offering in Uganda, where the majority of people have no access to grid electricity. Fenix not only significantly exceeded its own sales projections, but also deepened its partnership with MTN Uganda, the country’s largest mobile network operator. This Case Study highlights the successes and challenges faced along the way and presents the key lessons learned from the grant.