Regional disparities in emissions reduction and net trade from renewables

Operational constraints of the power system and inter-regional trade of electricity make it challenging to predetermine the reduction in emissions from the integration of solar and wind power. Using spatially resolved historical data for solar and wind generation, fossil fuel-based generation, emissions and exports, we isolate the impacts of renewable integration for multiple regions spanning the United States. Here we show regional differences for the reduction of carbon dioxide, sulfur dioxide and nitrogen oxides emissions, with a wider range of outcomes for regional wind power. Given the heterogeneity in transmission infrastructure, some regions have limited capacity to increase electricity exports to neighbouring regions. For both solar and wind generation, we identify the regions that retain nearly all of the emissions reductions locally and those that increase net exports, reducing emissions in neighbouring regions. Our results show lower rates of emissions mitigation than previous studies that relied on less-contemporary data or utilized simulated renewable generation. These differences may reflect the longer-term trends in power-sector emissions reductions and the importance of utilizing observed renewable generation data.