Maryland’s “green” renewable portfolio standard (RPS) law may not be so green after all. According to the latest reports from the Maryland Public Service Commission, state utilities are fulfilling their RPS mandates mostly through the use of dirty energy sources like black liquor, a byproduct of the wood pulping process, and burning waste wood products.

Maryland’s RPS law mandates that state utilities must procure 20% of their retail electric sales from renewable energy by 2022.  The law was developed to “recognize and develop the environmental [read global warming] and consumer benefits associated with a diversity of renewable energy supplies to serve Maryland.”  Qualifying energy sources are divided into two tiers.  Tier 1 sources include biomass such as black liquor and wood waste.  Utilities comply with the mandate through the purchase of renewable energy credits (RECs), which is equal to one megawatt-hour of energy generated from a qualified renewable source, or an alternative compliance payment penalty.