Since 2004, AEP invested more than $5 billion to install state-of-the-art environmental controls that have resulted in significant reductions in regulated emissions from our power plants. We built nine scrubbers on 7,900 megawatts (MW) of our coal-fired generating capacity between 2003 and 2011 and selective catalytic reduction systems (SCRs) on more than 11,000 MW since 2001. As a result, sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions have been reduced by about 80 percent from 1980 levels. .