Renewable energy production across U.S. states: convergence or divergence?

This study explores the degree to which per capita aggregate renewable energy production is converging across U.S. states. Specifically, we examine both relative (club) convergence and weak σ-convergence. The results reject overall convergence in per capita aggregate renewable energy production for the panel of U.S. states, but identifies two convergence clubs. The results also suggest that there is considerable heterogeneity in the number of convergence clubs for the different subcomponents of per capita renewable energy production and consumption (biomass, geothermal, hydropower, solar and wind). We examine the factors which are associated with the emergence of the convergence clubs at the aggregate level. In the case of per capita aggregate renewable energy production, the average marginal effects from the logit analysis indicate that neighboring states with renewable portfolio standards, mandatory green power options, maximum effective retail rate increase, and per capita CO₂ emissions are associated with a higher likelihood of being in the convergence club with higher per capita renewable energy production. However, interconnection standards, having a public benefit fund, renewable energy certificates trading, compliance penalities, and per capita fossil fuel production are correlated with a lower likelihood of being in the convergence club with higher per capita renewable energy production. We also consider the factors correlated with convergence for the subcomponents of per capita renewable energy production and consumption, with the results suggesting considerable heterogeneity of the various factors at the subcomponent level.