Renewable portfolio standards (RPS) programs are not likely to represent the most cost-effective path towards achieving air quality and climate benefits, but the data suggest that US RPS programs are, on a national basis, cost-effective when considering externalities such as health and infrastructure damage from climate change-related effects. That’s the lead conclusion of what the study’s authors call “the first national-level, integrated assessment of the future costs and benefits of existing RPS policies.”
Nine authors at Lawrence Berkeley and National Renewable Energy Laboratories in the US studied the nationally aggregated outcomes from RPS programs currently running in 29 States and the District of Columbia. Under a continuation of existing policies, as they were in June 2016, the authors project that renewables would reach 26% of total US electricity generation by 2030 and 40% by 2050.
The authors also calculated the implications of a reference scenario where all such policies were discontinued after 2014, and a “high RE” outcome. Under a continuation of the existing policies, then, the present value of incremental system costs (2015–2050) relative to the Reference case ranges from an additional cost of $31 billion to an actual cost savings of $31 billion (0.8% higher to 0.7% lower system costs), depending on the direction of future costs of natural gas and renewables technologies. But the real savings come from improved air quality, $48–$175 billion worth on a discounted, present-value basis, mostly in reduced human mortality; and $161 billion in discounted global benefits based on a central value for the social cost of carbon. Other benefits appear in reduced water use for fossil-burning units.