This work leverages a uniquely-constructed dataset of the US electric grid, integrated into a general equilibrium framework, to assess the costs associated with implementing greenhouse gas policies in the US electric sector.  Particular attention is paid to the current menu of available generation and abatement technologies and how substitution among those technologies generates both costs and ancillary benefits in meeting policy requirements.  Specifically, we find that while gross policy costs associated with 10-20% greenhouse-gas abatement in the electric sector are on the order of $10 Bn., much of that cost is offset by the ancillary benefits of reduced morbidity and mortality arising from lower levels of NOx and SOx as particulate-matter precursors.  With only a subset of ancillary benefits considered, greenhouse-gas abatement in the electric sector may well be a "no regrets'" policy.