| Alliant Energy | 2004 |
| Ameren Illinois | 2010 |
| American Council for an Energy-Efficient Economy (ACEEE) | 2000 |
| Argonne National Laboratory | 2011 |
| Bidgely | 2018 |
| Bradford White Corporation | 2019 |
| Cadmus | 2004 |
| Cedar Falls Utilities | 2011 |
| Celia Johnson Consulting | 2018 |
| Center for Energy and Environment | 2004 |
| CenterPoint Energy | 2004 |
| City Water, Light & Power | 2007 |
| CLEAResult | 2013 |
| CMC Energy Services | 2018 |
| Columbia Water and Light | 2008 |
| Commonwealth Edison | 2000 |
| Cooperative Educational Service Agency 10 (CESA 10) | 2016 |
| D+R International | 2011 |
| Dayton Power & Light | 2011 |
| DNV GL | 2005 |
| E Source | 2010 |
| Edison Foundation Institute for Electric Innovation | 2009 |
| Elevate Energy | 2017 |
| Energy Education Council | 2007 |
| Energy Insight, Inc. | 2015 |
| Energy Resources Center at UIC | 2000 |
| Energy Solutions | 2017 |
| EnergyX Solutions Inc | 2019 |
| Erthe Energy Solutions | 2018 |
| Evergreen Consulting Group | 2018 |
| Evergy (Formerly KCP&L + Westar) | 2016 |
| EZ Green Home | 2019 |
| Franklin Energy | 2008 |
| Fresh Energy | 2018 |
| Frontier Energy | 2017 |
| Future Energy Enterprises, LLC | 2009 |
| Geothermal Alliance of Illinois | 2011 |
| Geothermal Exchange Organization (GEO) | 2014 |
| Green Home Experts | 2014 |
| GTI | 2017 |
| Honeywell Smart Grid Solutions | 2014 |
| ICF | 2000 |
| Illinois EPA | 2017 |
| Indiana Office of Energy Development | 2014 |
| Indianapolis Power & Light Company | 2003 |
| Iowa Economic Development Authority | 2014 |
| JadeTrack | 2019 |
| Leidos | 2010 |
| Lime Energy | 2012 |
| Lockheed Martin | 2009 |
| Louisville Gas & Electric Company and Kentucky Utilities (LGE KU) | 2012 |
| MaxLite | 2018 |
| Michigan Agency for Energy - Michigan Energy Office | 2006 |
| Michigan Saves | 2018 |
| MidAmerican Energy Company | 2006 |
| Milepost Consulting, SPC | 2019 |
| Missouri Botanical Garden's EarthWays Center | 2009 |
| Missouri Department of Natural Resources | 2000 |
| Missouri Energy Initiative | 2014 |
| Morgan Marketing Partners | 2010 |
| Navigant Consulting, Inc. | 2003 |
| Nebraska Energy Office | 2014 |
| Nicor Gas | 2012 |
| NIPSCO | 2014 |
| Northwest Energy Efficiency Council (NEEC) | 2008 |
| Office of Energy Policy, Division of Energy Assistance for the Kentucky Energy and Environment Cabinet | 2014 |
| PACENation | 2018 |
| Panasonic, HVAC Division | 2019 |
| Peoples Gas | 2010 |
| Philips Lighting | 2012 |
| Power TakeOff, Inc. | 2017 |
| Recleim | 2017 |
| Resource Action Programs | 2012 |
| Resource Innovations | 2016 |
| Rheem Manufacturing | 2019 |
| Rivenoak Consulting, Inc. | 2018 |
| Sodexo | 2017 |
| South Dakota Bureau of Administration , Energy Management Office | 2014 |
| Southern Minnesota Municipal Power Agency | 2004 |
| Summerhill | 2016 |
| The National Energy Improvement Fund (NEIF) | 2015 |
| Threshold | 2017 |
| Uplight | 2019 |
| Upper Peninsula Power Company | 2019 |
| VEIC | 2015 |
| Village of Oak Park | 2018 |
| We Energies | 2019 |
| West Virginia Office of Energy | 2017 |
| Willdan | 2001 |
| Wisconsin Office of Energy Innovation | 2014 |
| Wisconsin Public Service | 2019 |
| WPPI Energy | 2018 |
| Xcel Energy | 2000 |
