Close to 80% of the world’s energy supply could be generated through renewables by mid-century with the right enabling public policies. Policies can play a fundamental role in promoting a sustainable energy-mix and it is key to measure their effectiveness in the medium and long run. What is the most effective way to measure and monitor this effectiveness? What can we learn from Brazil, one of the first emerging countries to refocus its national energy strategies toward renewable energy? And from South Africa, which committed to develop 42% of additional capacity in renewable by 2030? These are some of the questions addressed in the report commissioned by UNEP DTIE: Assessing the effectiveness of policies to support renewable energy. The report demonstrates the importance of monitoring policy effectiveness by using the Policy Effectiveness Indicator (PEI) approach.i While there is no one-size-fits all approach to designing renewable policies, a number of principles of policy design exist, which can dramatically increase the effectiveness and efficiency of renewable energy policies. Some recommendations for policy- makers include: - assessing which of the three factors is holding back deployment, - making sure that all three factors are robust for a high PEI score to be registered, - implementing a detailed monitoring and reporting for all of the different aspects of renewable policy, and - considering the entire policy framework into which incentives schemes are inserted.