System-level impacts of voluntary carbon-free electricity procurement strategies

This study assesses the system-level impacts of carbon-free electricity procurements by voluntary actors in the western United States, accounting for induced changes in both system operations and installed capacities. We find that in the current US policy environment, procurement strategies that match participants’ demand with carbon-free generation on an annual basis have minimal impact on long-run system-level CO2 emissions. Similar outcomes occur when participants calculate their annual emission impacts using short-run marginal emission rates and attempt to offset these with their procurements. In contrast, we find that matching participants’ demand on an hourly basis with carbon-free generation can drive significant reductions in system-level CO2 emissions while incentivizing advanced clean firm generation and long-duration storage technologies that would not otherwise see market uptake. Greater emission impacts are correlated with increased participant costs. We further find that government-imposed clean electricity standards can increase the effectiveness of all forms of voluntary procurement.