This first-in-the-nation regional effort to lower carbon emissions from power plants is actually a cap-and-invest program. Power plants buy emission allowances through quarterly auctions for the right to pollute above a set cap. The states get the money, most of which they’re supposed to invest in consumer benefits such as energy efficiency programs that help lower energy use further. From 2009, when RGGI – pronounced Reggie – officially kicked in, through 2017, that system sent $2.4 billion back to the then nine member states, according to the most recent report from RGGI. Power plant emission reductions exceed those in rest of U.S. by 90%.