The average wholesale electricity spot price reached $105 per megawatt hour in May 2026, up around $49 on the preceding period. The Electricity Authority attributed it to higher demand combined with lower wind generation and roughly 100 megawatts of geothermal generation offline due to an outage.
That single month illustrates the structural feature business users need to plan around.
Why New Zealand prices move so sharply
A high renewable share is an emissions advantage and a volatility source. Hydro depends on inflows, wind depends on wind, and neither can be dispatched on demand.
When renewable output falls, the marginal generator setting the price is thermal — and gas has been getting scarcer and more expensive as reserves decline. So a quiet wind week combined with a plant outage moves the price a long way in a short time.
Between 2019 and early 2026 the average price rose to around $160 per MWh, though expected wholesale prices have been falling more recently as new renewable capacity enters the system.
Supply adequacy is the live concern
Insufficient increase in installed generation, particularly a stagnation in seasonal firming capacity, has created a risk of breaching security standards if new generation is delayed.
Firming is the part that matters and gets least attention. A system with plenty of wind and solar still needs something that can run when they are not producing — hydro storage, geothermal, thermal, or demand that can move.
Higher prices and improving renewable economics have triggered a wave of grid-scale investment, and the Electricity Authority publishes a generation investment pipeline dashboard showing planned projects. The question is timing rather than intent.
What business users can actually do
Understand what you are exposed to. Most business users buy on a contract that insulates them from spot movements, but the contract price reflects what the retailer expects wholesale to do. Volatility reaches you at renewal rather than daily.
Larger users on spot-linked arrangements face it directly, and should understand exactly what their exposure is before a volatile period rather than during one.
Demand flexibility is worth money. If any part of your load can move — running a process overnight, pre-cooling, shifting a batch — that flexibility has value, and increasingly there are arrangements that pay for it.
Watch demand charges, not just energy. For many commercial users the network charge based on peak demand is a large share of the bill. Reducing the peak matters even if total consumption is unchanged, which makes load management and staggering equipment starts worth doing.
Efficiency reduces exposure permanently. The cheapest unit is the one you do not use, and efficiency work is the only lever that reduces both consumption and peak.
The process heat connection
For manufacturers considering electrification of process heat, price volatility is part of the business case rather than a footnote.
The sequence that produces the best economics is unchanged: reduce demand through insulation and controls, recover waste heat through exchangers, optimise the existing system, and only then change the fuel. Plants that follow that order frequently find the replacement heat source can be substantially smaller.
Establishing the temperature the process actually requires is the first engineering task, because processes are frequently run hotter than necessary and heat pumps become viable below certain thresholds.
Connection is the other constraint
For anyone developing generation or adding significant load, network capacity determines what is possible. Transmission connection through Transpower runs on lead times measured in years; distribution connection depends on local hosting capacity, which varies dramatically between locations a few kilometres apart.
Talk to the network owner before site selection is final. Hosting capacity has killed more projects than planning provisions.
Where the data is
The Electricity Authority publishes wholesale prices, demand, generation and market analytics through its Electricity Market Information platform at emi.ea.govt.nz, under a default open licence. The generation investment pipeline dashboard shows planned projects.
MBIE publishes energy statistics, and EECA publishes efficiency and decarbonisation material.
Figures: Electricity Authority market reporting, May 2026 spot price; longer-run average to early 2026. General information only.
