Which I guess is a strong argument that the ETS was overallocated. Polluters didn't need all that carbon, so they didn't buy it. Fortunately, the available volume is being brutally cut next year, to just 6 million tons - which should help rebalance things. Unfortunately, National has cancelled expected cuts to industrial allocations (aka pollution subsidies) - and after next year these subsidies will exceed auction volumes. Meaning the benefits of the system will accrue to those subsidised large polluters rather than the public. And the systematic overallocation of subsidies means these polluters are already making out like bandits at our expense.
I don't think this system is sustainable. For the system to work and help us meet our targets, ETS volumes need to decrease every year - and that includes industrial allocations. But beyond that, I don't think there's public support for a tool which simply operates to enrich favoured cronies at public expense - especially when said cronies are (by definition) New Zealand's worst polluters, and some of them are not lifting a finger to change that (while others are demanding that their subsidies continue, even as they take government money to reduce their emissions). If the ETS is to continue, it needs wholesale reform. And that includes ending the subsidy regime. These polluters have been receiving subsidies for 16 years now - more than enough time for them to transition to cleaner technology. If they have not, that is a poor business decision, for which they deserve to be held accountable. End the subsidies, make them pay their full social costs, and if they can't, then they were never really "profitable" anyway.