State-level renewable portfolio standards: Evaluating their effectiveness in increasing renewable electricity generation and reducing carbon emissions

The renewable portfolio standard (RPS) is a key state-level policy instrument meant to encourage renewable energy development and address climate change by mandating increased electricity generation from low-carbon renewable sources. In analyzing the effectiveness of RPS policies, I hypothesize that these policies should increase renewable electricity generation and reduce carbon dioxide emissions from electricity generation. Additionally, I hypothesize that more stringent RPS policies should allow for greater increases in renewable energy generation and larger declines in CO2 emissions. To test these hypotheses, I use pooled and fixed effects models to examine how RPS policies play a role in affecting renewable electricity generation and CO 2 emissions. My results suggest that these policies increase electricity generation from renewable sources and that the stringency of these policies matters. However, the results are mixed in regard to their effectiveness in reducing CO2 emissions. These findings suggest that RPS policies as they are now may not be the best way to reduce CO2 emissions. Other policies that more directly target emissions may be necessary for states to see the emissions reductions they desire.