| Pacific Gas & Electric Co. (PG&E) | PG&E Corp. | utility safety violation | 2016 | CA-PUC | $25,600,000 |
| Duke Energy Progress | Duke Energy | environmental violation | 2015 | NC-ENV | $25,116,883 |
| Florida Power & Light Co. | NextEra Energy | energy market violation | 2009 | FERC | $25,000,000 |
| Arizona Public Service Company | Pinnacle West Capital | consumer protection violation | 2021 | AZ-AG | $24,750,000 |
| Southern California Edison Co. | Edison International | utility safety violation | 2014 | CA-PUC | $24,500,000 |
| Illinois Power Co. and Dynergy Midwest Generation | Ameren | environmental violation | 2005 | IL-AG | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $24,000,000 |
| ILLINOIS POWER COMPANY | Ameren | environmental violation | 2005 | EPA | $24,000,000 |
| Reliant Energy Services Inc. | NRG Energy | price-fixing or anti-competitive practices | 2007 | USAO | $22,200,000 |
| American Electric Power Co. | American Electric Power | energy market violation | 2005 | FERC | $21,000,000 |
| National Grid | National Grid | utility safety violation | 2021 | NY-PSC | $21,000,000 |
| Pacific Gas & Electric Co | PG&E Corp. | utility safety violation | 2022 | CA-SONDA | $20,250,000 |
| PG&E Corp. | PG&E Corp. | environmental violation | 2008 | private lawsuit-state | $20,000,000 |
| Virginia Electric Power Co. | Dominion Energy | environmental violation | 2000 | EPA | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $19,200,000 |
| ABB Ltd. | ABB Ltd. | Foreign Corrupt Practices Act | 2010 | DOJ_CRIMINAL | $19,000,000 |
| Ohio Edison | FirstEnergy | environmental violation | 2005 | MULTI-AG | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $18,900,000 |
| Peoples Gas Light and Coke Co. | WEC Energy Group | consumer protection violation | 2016 | IL-AG | $18,750,000 |
| National Grid | National Grid | utility service violation | 2012 | MA-DPU | $18,725,000 |
| Peoples Gas | WEC Energy Group | consumer protection violation | 2016 | IL-ICC | $18,500,000 |
| Reliant Energy Services, Inc. | NRG Energy | price-fixing or anti-competitive practices | 2003 | CFTC | $18,000,000 |
| Dynegy, Inc. | Vistra Energy | benefit plan administrator violation | 2008 | private lawsuit-federal | $17,900,000 |
| PG&E | PG&E Corp. | wage and hour violation | 2009 | private lawsuit-state | $17,250,000 |
| AES Alamitos, LLC | AES Corp. | environmental violation | 2000 | CA-SCAQMD | $17,000,000 |
| Pacific Gas & Electric Co. (PG&E) | PG&E Corp. | utility safety violation | 2012 | CA-PUC | $16,760,000 |
| Southern California Edison Company | Edison International | utility administrative violation | 2015 | CA-PUC | $16,740,000 |
| Tampa Electric Company | Emera | environmental violation | 2000 | EPA | $16,500,000 |
| Midwest Generation, EME, LLC | NRG Energy | labor relations violation | 2010 | NLRB | $16,184,587 |
| e prime, Inc. | Xcel Energy | price-fixing or anti-competitive practices | 2004 | CFTC | $16,000,000 |
| American Municipal Power | American Municipal Power | environmental violation | 2010 | EPA | $15,850,000 |
| AmerenUE | Ameren | energy market violation | 2006 | FERC | $15,000,000 |
| Southern Company | Southern Company | benefit plan administrator violation | 2007 | private lawsuit-federal | $15,000,000 |
| Southern California Edison Company | Edison International | utility safety violation | 2014 | CA-PUC | $15,000,000 |
| Luminant Energy Company LLC | Vistra Energy | utility service violation | 2008 | TX-PUC | $15,000,000 |
| CMS Energy Resource Management | CMS Energy | price-fixing or anti-competitive practices | 2020 | private lawsuit-federal | $15,000,000 |
| Eversource Energy Service Company | EverSource Energy | benefit plan administrator violation | 2023 | private lawsuit-federal | $15,000,000 |
| San Diego Gas & Electric (SDG&E) | Sempra Energy | utility safety violation | 2010 | CA-PUC | $14,750,000 |
| CenterPoint Energy Services, Inc. | CenterPoint Energy | price-fixing or anti-competitive practices | 2019 | private lawsuit-federal | $14,750,000 |
| Pacific Gas & Electric Co. (PG&E) | PG&E Corp. | utility administrative violation | 2013 | CA-PUC | $14,350,000 |
| Virginia Electric & Power Company, d/b/a Dominion Energy Virginia | Dominion Energy | energy market violation | 2019 | FERC | $14,000,000 |
| Virginia Electric Power Co. | Dominion Energy | environmental violation | 2003 | MULTI-AG | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $13,900,000 |
| Consolidated Edison | Consolidated Edison | employment discrimination | 2002 | private lawsuit-federal | $13,838,137 |
| Reliant Energy | NRG Energy | energy market violation | 2003 | FERC | $13,800,000 |
| CenterPoint Energy | CenterPoint Energy | consumer protection violation | 2006 | MN-AG | $13,500,000 |
| PSE&G FOSSIL LLC | Public Service Enterprise | environmental violation | 2007 | EPA | $13,400,000 |
| Dominion Energy | Dominion Energy | environmental violation | 2013 | EPA | $13,200,000 |
| Edison International | Edison International | benefit plan administrator violation | 2018 | private lawsuit-federal | $13,161,491 |
| Northern Indiana Public Service Co. | NiSource | environmental violation | 2011 | IN-AG | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $13,000,000 |
| Mirant Americas Energy Marketing LP | NRG Energy | price-fixing or anti-competitive practices | 2004 | CFTC | $12,500,000 |
| KeySpan Corporation | National Grid | price-fixing or anti-competitive practices | 2010 | DOJ_ANTITRUST | $12,000,000 |
| Atmos Energy | Atmos Energy | energy market violation | 2011 | FERC | $12,000,000 |
| Pacific Gas and Electric Co. | PG&E Corp. | utility safety violation | 2022 | CA-PUC | $12,000,000 |
| East Kentucky Power Cooperative | East Kentucky Power Cooperative | environmental violation | 2007 | EPA | $11,400,000 |
| Mirant Energy Trading LLC | NRG Energy | fraud | 2007 | DOJ_CRIMINAL | $11,000,000 |
| SCANA Corporation | Dominion Energy | energy market violation | 2007 | FERC | $10,800,000 |
| Consolidated Edison Company of New York, Inc. | Consolidated Edison | utility service violation | 2020 | NY-PSC | $10,750,000 |
| Consolidated Edison Company of New York, Inc. | Consolidated Edison | utility safety violation | 2005 | NY-PSC | $10,600,000 |
| Aquila, Inc. | Evergy Inc. | benefit plan administrator violation | 2007 | private lawsuit-federal | $10,500,000 |
| CenterPoint Energy Resources Corp. | CenterPoint Energy | consumer protection violation | 2021 | AR-AG | $10,400,000 |
| Consumers Energy | CMS Energy | environmental violation | 2014 | EPA | $10,250,000 |
| Nicor, Inc. | Southern Company | accounting fraud or deficiencies | 2007 | SEC | $10,000,000 |
| PSEG Long Island | Public Service Enterprise | utility service violation | 2020 | NY-PSC | $10,000,000 |
| Southern California Edison | Edison International | utility safety violation | 2022 | CA-PUC | $10,000,000 |
| Dynegy, Inc. | Vistra Energy | benefit plan administrator violation | 2007 | private lawsuit-federal | $9,975,000 |
| Southern California Gas Co. | Sempra Energy | utility administrative violation | 2022 | CA-PUC | $9,807,000 |
| Mirant Corp. | NRG Energy | benefit plan administrator violation | 2006 | private lawsuit-federal | $9,700,000 |
| First Solar Inc. | First Solar | wage and hour violation | 2020 | private lawsuit-federal | $9,631,078 |
| American Electric Power Company Inc. | American Electric Power | price-fixing or anti-competitive practices | 2017 | private lawsuit-federal | $9,400,000 |
| Duke Energy Trading and Marketing L.L.C. | Duke Energy | price-fixing or anti-competitive practices | 2017 | private lawsuit-federal | $9,400,000 |
| Westar Energy | Evergy Inc. | benefit plan administrator violation | 2006 | private lawsuit-federal | $9,250,000 |
| New York State Electric & Gas Corp | Iberdrola | utility service violation | 2020 | NY-PSC | $9,000,000 |
| Alliant Energy | Alliant Energy | benefit plan administrator violation | 2014 | private lawsuit-federal | $8,936,437 |
| Bay State Gas Company dba Columbia Gas of Massachusetts | EverSource Energy | consumer protection violation | 2013 | MA-AG | $8,900,000 |
| Boston Edison Co. | EverSource Energy | environmental violation | 2006 | MA-AG | $8,600,000 |
| American Electric Power | American Electric Power | environmental violation | 2013 | MULTI-AG | $8,500,000 |
| Cinergy Corp. | Duke Energy | environmental violation | 2000 | NY-AG | $8,500,000 |
| Niagara Mohawk Power Corp. | National Grid | environmental violation | 2005 | NY-AG | $8,500,000 |
| SoCalGas | Sempra Energy | environmental violation | 2017 | CA-SCAQMD | $8,500,000 |
| FIRST ENERGY CORP | FirstEnergy | environmental violation | 2010 | EPA | $8,500,000 |
| VIRGINIA ELECTRIC & POWER COMPANY | Dominion Energy | environmental violation | 2016 | EPA | $8,300,000 |
| Southern California Gas Company | Sempra Energy | consumer protection violation | 2019 | CA-PUC | $8,058,200 |
| AMERICAN ELECTRIC POWER | American Electric Power | environmental violation | 2020 | EPA | $8,025,000 |
| OHIO EDISON CO, ET. AL. | FirstEnergy | environmental violation | 2005 | EPA | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $8,005,000 |
| Xcel Energy, Inc. | Xcel Energy | benefit plan administrator violation | 2005 | private lawsuit-federal | $8,000,000 |
| Connecticut Light & Power | EverSource Energy | consumer protection violation | 2006 | CT-AG | $8,000,000 |
| National Grid | National Grid | consumer protection violation | 2009 | MA-AG | $8,000,000 |
| Southern California Edison Co. (SCE) | Edison International | utility safety violation | 2018 | CA-PUC | $8,000,000 |
| Pacific Gas & Electric Co. (PG&E) | PG&E Corp. | utility safety violation | 2017 | CA-PUC | $8,000,000 |
| Pacific Gas and Electric Company | PG&E Corp. | utility safety violation | 2023 | CA-PUC | $8,000,000 |
| Northern Indiana Public Service Company | NiSource | energy market violation | 2024 | FERC | $7,700,000 |
| DTE Energy | DTE Energy | environmental violation | 2020 | EPA | $7,300,000 |
| TXU Corp. | Vistra Energy | benefit plan administrator violation | 2008 | private lawsuit-federal | $7,250,000 |
| Interstate Power and Light, a subsidiary of Alliant Energy | Alliant Energy | environmental violation | 2015 | EPA | $7,100,000 |
| National Grid | National Grid | consumer protection violation | 2018 | MA-AG | $7,000,000 |
| Constellation NewEnergy Gas Division, LLC | Constellation Energy Corporation | energy market violation | 2008 | FERC | $6,899,416 |
| Duke Energy Carolinas, LLC | Duke Energy | environmental violation | 2016 | NC-ENV | $6,831,005 |
| DAYTON POWER AND LIGHT COMPANY | AES Corp. | labor relations violation | 2000 | NLRB | $6,800,000 |
| PG&E | PG&E Corp. | consumer protection violation | 2006 | CA-SFCA | $6,500,000 |
| SCANA Energy Marketing Inc. | Dominion Energy | consumer protection violation | 2014 | private lawsuit-federal | $6,500,000 |
| Progress Energy Inc. | Duke Energy | energy market violation | 2005 | FERC | $6,400,000 |
| AmeriGas Propoane LP | UGI Corp. | price-fixing or anti-competitive practices | 2020 | private lawsuit-federal | $6,312,500 |
| AMERICAN ELECTRIC POWER CO (NATIONAL CASE) | American Electric Power | environmental violation | 2007 | EPA | (*)Penalty amounts marked by an asterisk are ones announced by more than one agency. Parent penalty totals are adjusted to avoid double-counting. $6,225,000 |
| Public Service Company of Oklahoma | American Electric Power | labor relations violation | 2004 | NLRB | $6,029,281 |
