The electricity sector is responsible for roughly 40 percent of U.S. carbon dioxide (CO2) emissions, and a shift away from conventional coal-fired generation is an important component of the U.S. strategy to reduce greenhouse gas emissions. Toward that goal, several proposals for a clean energy standard (CES) have been put forth, including one espoused by the Obama administration that calls for 80 percent clean electricity by 2035 phased in from current levels of roughly 40 percent. This paper looks at the effects of such a policy on CO2 emissions from the electricity sector, the mix of technologies used to supply electricity, electricity prices, and regional flows of clean energy credits. The CES leads to a 30 percent reduction in cumulative CO2 emissions between 2013 and 2035 and results in dramatic reductions in generation from conventional coal. The policy also results in fairly modest increases on national electricity prices, but this masks a wide variety of effects across regions.