Earlier this year the Taranaki Regional Council granted air emission resource consents for a new station, though Todd Energy strongly opposed such a proposal, arguing that the present 70MW gas-fired cogeneration plant, in which it is a joint venture partner, be retained.

Todd Energy and Fonterra are partners in the existing cogeneration plant, which helps power the world’s largest single-site diary complex, though gas supply contracts expire next year.

In its notice of appeal to the environment court, Todd Energy says the TRC’s consent decision failed to give proper weight to the adverse effects a coal-fired station would have on the existing cogeneration plant, which would include corrosion from sulphur dioxide emissions, damage from coal dust and increased carbon dioxide emissions.

Todd also says the Fonterra dual-fuel station proposal is unnecessary and an inefficient use of natural and physical resources. It asks that the consents either be cancelled or granted, though subject to a number of new conditions.

The possible move to coal was foreshadowed last March by Fonterra chief executive Andrew Ferrier who said Fonterra had 29 plants in New Zealand that ran on natural gas. Given the lack of competitively priced gas, converting these plants to coal over the next 10 years would represent a huge amount of capital spent for no real benefit to Fonterra’s farmers.

The Whareroa saga adds another dimension to NZ's increasingly tight and complex gas supply picture, as major industrial users contemplate the possibility of insufficient gas in a post-Maui age and energy companies fight for the future of gas as a fuel.