The majority of US states use a renewable portfolio standard (RPS) to achieve clean energy targets. RPS programs typically set annual clean energy production levels, but they ignore the significant variations in greenhouse gas emissions intensity of the grid at different times of the day and at different locations. Newly available locational marginal emissions (LME) data, which are collected at thousands of physical locations and updated every five minutes, provide insights into where and when the electricity sector produces the most and least GHG emissions.
Incorporating LMEs into RPSs would allow states to identify and reward “high impact” clean energy production: that which replaces the dirtiest generation. This report “Using New Marginal Emissions Data to Improve State Renewable Portfolio Standards” by Center on Global Energy Policy examines the impact that incentivizing clean energy production at high LME times and locations could have on reducing emissions in RPS programs. In five scenarios based on data from four states in the PJM grid (Illinois, New Jersey, Pennsylvania, and Virginia), it examines hypothetical shifts in energy production from times and geographic areas with differing clean or dirty generation mixes.
Access the complete report here
