GLOSSARY OF TERMS Term Meaning AEGCo AEP Generating Company, an AEP electric utility subsidiary. AEP American Electric Power Company, Inc., an investor-owned electric public utility holding company which includes American Electric Power Company, Inc. (Parent) and majority- owned consolidated subsidiaries and consolidated affiliates. AEP Energy AEP Energy, Inc., a wholly-owned retail electric supplier for customers in Ohio, Illinois and other deregulated electricity markets throughout the United States. AEP Energy Supply, LLC A nonregulated holding company for AEP’s competitive generation, wholesale and retail businesses, and a wholly-owned subsidiary of AEP. AEP OnSite Partners A division of AEP Energy Supply, LLC that builds, owns, operates and maintains customer solutions utilizing existing and emerging distributed technologies. AEP Renewables A division of AEP Energy Supply, LLC that develops and/or acquires large scale renewable projects that are backed with long-term contracts with creditworthy counter parties. AEP System American Electric Power System, an electric system, owned and operated by AEP subsidiaries. AEP Texas AEP Texas Inc., an AEP electric utility subsidiary. AEP Transmission Holdco AEP Transmission Holding Company, LLC, a wholly-owned subsidiary of AEP. AEPEP AEP Energy Partners, Inc., a subsidiary of AEP dedicated to wholesale marketing and trading, hedging activities, asset management and commercial and industrial sales in deregulated markets. AEPSC American Electric Power Service Corporation, an AEP service subsidiary providing management and professional services to AEP and its subsidiaries. AEPTCo AEP Transmission Company, LLC, a wholly-owned subsidiary of AEP Transmission Holdco, is an intermediate holding company that owns the State Transcos. AEPTCo Parent AEP Transmission Company, LLC, the holding company of the State Transcos within the AEPTCo consolidation. AEPTHCo AEP Transmission Holding Company, LLC, a subsidiary of AEP, an intermediate holding company that owns transmission operations joint ventures and AEPTCo. AFUDC Allowance for Funds Used During Construction. AGR AEP Generation Resources Inc., a competitive AEP subsidiary in the Generation & Marketing segment. APCo Appalachian Power Company, an AEP electric utility subsidiary. APTCo AEP Appalachian Transmission Company, Inc., a wholly-owned AEPTCo transmission subsidiary. APSC Arkansas Public Service Commission. CAA Clean Air Act. CO 2 Carbon dioxide and other greenhouse gases. Conesville Plant A single unit coal-fired generation plant totaling 651 MW located in Conesville, Ohio. The plant is jointly owned by AGR and a nonaffiliate. Cook Plant Donald C. Cook Nuclear Plant, a two-unit, 2,288 MW nuclear plant owned by I&M. CSPCo Columbus Southern Power Company, a former AEP electric utility subsidiary that was merged into OPCo effective December 31, 2011. ERCOT Electric Reliability Council of Texas regional transmission organization. ETT Electric Transmission Texas, LLC, an equity interest joint venture between AEP Transmission Holdco and Berkshire Hathaway Energy Company formed to own and operate electric transmission facilities in ERCOT. Federal EPA United States Environmental Protection Agency. FERC Federal Energy Regulatory Commission. FIP Federal Implementation Plan. I&M Indiana Michigan Power Company, an AEP electric utility subsidiary. i When the following terms and abbreviations appear in the text of this report, they have the meanings indicated below.