| Alectra | Vaughan |
| Bracebridge Generation Limited | Bracebridge |
| Enbridge Green Power, Transmission and Emerging Technology, Enbridge Eastern Regional Operations | Kincardine |
| EPCOR Electricity Distribution Ontario | Collingwood |
| ERTH Power Corporation, ERTH Power | Ingersoll |
| Festival Hydro Inc. | Stratford |
| Hydro One | Toronto |
| Lakefront Utility Services Inc | Cobourg |
| Lakeland Power Distribution Limited, Huntsville Office | Huntsville |
| NT Power | Midland |
| Peterborough Utilities Group | Peterborough |
| Tay Hydro, Tay Township | Tay |
| Wasaga Distribution | Wasaga Beach |
| Westario Power | Brockton |