Case Study: Simpa achieves rapid deployment of pay‑as‑you‑go solar for off‑grid households with ThoughtWorks

Simpa - Customer Case Study

ThoughtWorks’ Social Impact Program partnered with Simpa Networks, a for‑profit social enterprise founded in 2010 to bring clean, sustainable electricity to off‑grid households. Faced with roughly 1.6 billion people lacking reliable power and low‑income families who cannot afford the $400 upfront cost of high‑quality solar systems, Simpa needed a new pricing and payment model to make solar radically affordable and financially viable without traditional lending.

The teams implemented Simpa’s Progressive Purchase pay‑per‑use model—customers make flexible cash top‑ups at local agents, receive SMS codes, and unlock purchased energy on their SES; top‑ups also pay down the unit until it is permanently unlocked. ThoughtWorks built the SMS‑enabled revenue management system (Java, Kannel, Tomcat, MySQL) in 12 weeks, enabling a Karnataka pilot that moved to commercial use, increased investor confidence and set the stage for scalable, market‑driven expansion of clean energy.

Simpa