AEP Ohio | 2009 |
Alliant Energy | 2004 |
Ameren Illinois | 2010 |
Cedar Falls Utilities | 2011 |
CenterPoint Energy | 2004 |
City Utilities of Springfield, MO | 2015 |
City Water, Light & Power | 2007 |
Columbia Water and Light | 2008 |
Commonwealth Edison | 2000 |
Consumers Energy | 2010 |
Dayton Power & Light | 2011 |
DTE Energy | 2009 |
Duke Energy | 2006 |
East Kentucky Power Cooperative | 2012 |
Evergy (Formerly KCP&L + Westar) | 2016 |
Indianapolis Power & Light Company | 2003 |
Louisville Gas & Electric Company and Kentucky Utilities (LGE KU) | 2012 |
MidAmerican Energy Company | 2006 |
Minnesota Energy Resources Corporation | 2007 |
Minnesota Power | 2014 |
Nicor Gas | 2012 |
NIPSCO | 2014 |
North Shore Gas | 2010 |
Ohio's Electric Cooperatives | 2014 |
Peoples Gas | 2010 |
SEMCO Energy Gas Company | 2014 |
Southern Minnesota Municipal Power Agency | 2004 |
Spire | 2018 |
Upper Peninsula Power Company | 2019 |
Vectren Indiana South | 2016 |
Wabash Valley Power Association | 2004 |
We Energies | 2019 |
Wisconsin Public Service | 2019 |
WPPI Energy | 2018 |
Xcel Energy | 2000 |