KEY POINTS:
The initial reaction to Meridian Energy announcing it is "certified carbon zero" may have been subdued but chief executive Keith Turner believes consumer preference for buying electricity from a carbon-neutral supplier will build over time.
Meridian is not charging any more for its power as a result - unlike an earlier TrustPower scheme - but then, it doesn't cost the company much either.
"We have been able to do this more easily than others could," Turner said.
Meridian only generates from renewable sources - hydro and wind. In a normal year it generates about 23 per cent more than it needs to meet its contractual obligations to its customers. It is a net seller into the wholesale market.
Even in the driest year to date, it has been able to generate more than it needs as a retailer.
It is not a matter of a consumer knowing that the electricity he or she consumes flowed from a particular source. The consumer's assurance is that over a year Meridian puts more "green" energy into the pool than it needs to draw out to meet its customers' requirements.
To be certified carbon zero Meridian also has to cover the rest of its carbon footprint - the emissions it is responsible for - from its vehicles and other travel, to waste, paper usage, and even the lubricating oil used in its turbines.
Turner believes public opinion on climate change has shifted decisively within the past six or eight months.
"If we are right and the market is ready for carbon zero [electricity] then the thermal generators are probably going to have to raise their prices to pay for offsets. You could almost avoid the Government having to put on a carbon tax if the market spoke loudly enough and consumers said: 'We want carbon-zero electricity'."
As it is, the prospect of thermal generators facing a price for their carbon emissions has already had an effect. Contact Energy has shelved plans for another gas-fired plant at Otahuhu and is going to spend $2 billion on renewables generation instead. Mighty River Power has announced plans to spend $1 billion on geothermal projects over the next 10 years, and Meridian has $5 billion worth of projects, all renewable, in the pipeline.
