Power companies say Friday's ruling by the Electricity Authority on a huge spike in electricity prices in March leaves issues unresolved because it is open to submissions and counter submissions.
Genesis Energy raised prices to $20,000 a kilowatt hour on 26 March while some power lines were out for scheduled maintenance.
The Electricity Authority found the company broke no laws, but says an undesirable trading situation prevailed and has ordered the prices charged to be lowered.
While the ruling is open to lengthy debate, up to $100 million is effectively in limbo as companies work to produce final accounts by the end of June.
The ruling also leaves unresolved the status of Huntly power station, from where electricity is sometimes too expensive to be sold, but which needs to be kept ready in case of crisis.