This document summarizes a workshop on impact investing in solar energy for rural populations living in poverty. It discusses Greenlight Planet's (GP) mission to improve quality of life and economic opportunities for off-grid households by investing in manufacturers and distributors of affordable solar lights and home systems. GP has invested $225 million with 101 partners serving 1.2 billion people without electricity access. Lessons learned include the appeal of the pay-as-you-go model and strong customer demand for solar products. Challenges include lack of investor attention in Latin America and competition from cheap Chinese imports.