Sol Purpose is a pioneering public benefit corporation with a mission to further renewable energy development that serves the broader public interest. Sol Purpose was established to ensure the viability of the Bard Prison Initiative (BPI). After years of financial uncertainty, the leadership of BPI set out to establish innovative methods for funding its work and to redefine how non-profits can sustain themselves in the new, confounding American landscape. In doing so, Sol Purpose has created a new model for solar development that provides returns for investors and budget certainty for non-profits. Partnering with leaders in government, finance, and renewable energy, Sol Purpose is a 21st century response to the philanthropic foundation. We address social inequality through profitable investment in renewable energy, transforming the relationship between the corporate citizen and the public good.