Members O-P
| Member | |
| Ohm Energie SAS | |
| OK A.M.B.A | |
| Olerex | |
| Oomi Oy | |
| Ompex AG | |
| Optimax Energy GmbH | |
| Osaühing VKG Energia | |
| Ovako Bar AB | |
| Ovako Bar Oy Ab | |
| Oy AGA Ab | |
| Oy Elkraft Finland Ab | |
| Oy Perhonjoki Ab | |
| Oy Turku Energia-Åbo Energi Ab | |
| Oulun Energia Oy | |
| PD Power Oy | |
| PetroChina International (London) Co., Limited | |
| Pohjois-Karjalan Sähkö Oy | |
| Pori Energia Oy | |
| PowerField Energy B.V. | |
| Powerflow Commodities ApS | |
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| Priogen Holding B.V. | |
| Pure.energy GmbH | |
| PVO Power Management Oy | |
| Quadra Energy GmbH | |
| QUENT ApS |