Recently the New Zealand electricity sector has been taking a bit of a hammering. According to a Commerce Commission sanctioned report, consumers have been overcharged by $4.3b over a six year period (how’s that for a headline!). More specifically, the report concluded each of the four big generators – Meridian, Contact, Genesis and Mighty River – has been exercising the power the market’s design gives them to command unjustifiably high prices, at least during years when inflows to the hydro lakes are low as they were in 2001, 2003 and 2006.
New Zealand has two markets in electricity – the wholesale market and the retail market. The wholesale market is where generators sell their production to retailers (often the seller and purchaser are one and the same). These prices vary significantly depending on the conditions of that particular period (for example, how dry Southern Lakes are or whether a generation unit is out service).
The second market is the retail market, where retailers sell electricity to consumers. Prices here are typically very stable, with consumers seldom exposed to the vast variation that takes place period-on-period in the wholesale market.
In the long-run, the prices in the wholesale market feed through to the retail market. In other words, if a generator/retailer found themselves short of generation and thus had to buy excess generation on the wholesale spot market at relatively high rates, they would eventually pass through these additional costs to their consumers in the retail market.
The report is essentially saying that generator/retailers were able to use their dominance in the wholesale market to push up prices during periods of constrained supply, which consumers then ultimately had to pay for in the retail market.
The report also says that pricing in the wholesale electricity market is, in the absence of dry periods, typically competitive. A very important point made in the report is that no market is ‘textbook’ perfectly competitive and this is certainly the case in electricity, given its unique characteristics (in particular the need for supply to continuously meet demand).
Indeed, I would say that the wholesale electricity market is working almost exactly as intended. Pricing is commonly competitive except at times of tight supply, when generators are able to reap higher rewards that incentivise continued investment in generation (which is extremely expensive) so that ever-growing demand can be met into the future. And the Commerce Commission determined that the generators’ actions were a “lawful and rational exploitation of the opportunities the market gave them”. I doubt you’d be able to make nearly as impressive a headline out of that though…