Green power in New Zealand — what the claims mean

Green electricity is a harder claim to make honestly in New Zealand than in most countries, for a reason that sounds like good news and complicates everything: the grid is already largely renewable.

The physics first

There is one national grid. Every generator feeds into it and every consumer draws from it, and no arrangement of contracts changes which electrons arrive at your house. A green plan does not give you different electricity.

What it does is direct your money. That is a real thing, and where retail revenue goes influences what gets built, but it is a different claim from the one the marketing usually implies, and worth separating out before you compare anything.

The three claims, and what each is worth

Renewable generation. The company generates from hydro, wind or geothermal, or contracts specifically for it. The strongest of the three, because it is a statement about physical assets and is easy to substantiate.

Certificates. The company buys instruments certifying that a quantity of renewable generation happened somewhere. Legitimate as an accounting mechanism, and a weaker claim than owning the turbine, particularly in a market whose baseline is already highly renewable, where the certificates may attach to generation that would have happened regardless.

Carbon neutral through offsets. Emissions are calculated and then offset by buying something else. Offset quality varies enormously. This is the claim most worth asking detailed questions about: what was offset, through what scheme, verified by whom.

None of these is dishonest. They are just different, and they are routinely presented as interchangeable.

What we have verified

The table above is our generation field across the 8 companies we compare. Most rows read as not confirmed, and that is the honest state of it. We have not checked those claims on the companies' own sites, and an unchecked green rating is worse than an absent one because it looks like a finding.

We would rather publish an incomplete column than a full one we cannot stand behind. As each is verified against the company's own published material, the row fills in.

What to ask

• What exactly is the claim — generation, certificates, or offsets?
• What period does it cover, and is it re-verified annually?
• Who verified it, and is that documentation public?
• Is there a price difference against the same company's standard plan, and what is it buying?

A company generating renewably can answer all four in a sentence each. That, rather than the badge, is the signal.

We compare 8 power companies and can show you what each offers at your address, with the gaps left visible.