Commercial electricity prices in NZ: what South Island businesses pay in 2026

A business power bill has two halves. The energy price is set by your retail contract and follows the wholesale market, with a lag. The network half, lines and transmission charges, is regulated and reaches every bill through the retailer, whoever you buy from. Since April 2025 lines charges have risen sharply after the regulator's reset, while wholesale prices spiked and then, in 2026, fell.

What businesses pay

Commercial customers paid an average 25.5 cents a kWh ex GST in the year to March 2026, up 8.5 percent in a year and 52.5 percent since 2018. MBIE's figures are sales revenue over kWh sold, so lines, fixed charges and levies are all in, and they are weighted by kWh: a food processor using millions of kWh pays less per kWh than a shop, and farms sit above the commercial average.

Lines charges: the 2025 reset

From 1 April 2025 the Commerce Commission reset what the lines companies it regulates may earn for 2025 to 2030. Their distribution revenue rose 24 percent on average in the first year. From 2026/27 each network's allowed revenue grows faster than inflation, at CPI plus 12.3 percent for OtagoNet, 10.7 for EA Networks, 9.8 for Orion and 8.3 for Network Tasman a year, with forecast increases limited to an average 10 percent a year per connection after inflation. Transpower's transmission revenue rose 16.2 percent to $976.7 million in 2025/26 and 16.9 percent to $1,141.4 million in 2026/27, and every lines company passes it through.

What each lines company said its charges did is below, using the figure closest to a business connection where it gives one. On Orion, the average small and medium business paid 22 percent more from April 2025, and the average general business connection another 15.5 percent from April 2026. Aurora Energy moved from its own customised path to the default path in April 2026, and the Commission put the household increase at about $15 a month ex GST.

How a lines company bills a business matters as much as the headline: some charge mostly per kWh, others per kVA of capacity or on peak demand. Our battery storage guide shows which networks charge demand a battery can cut, and our Nelson Tasman page what a solar kWh saves on a network with low lines charges.

Wholesale prices: the 2024 spike and the 2026 fall

Wholesale prices at Benmore, the South Island reference node, averaged $192 a MWh in 2024 and $145 in 2025, and peaked at $476 in August 2024, when low hydro lakes met a gas shortage, cold weather and little wind. The gas has been falling for years: major-field output was 435 TJ a day in 2020 and 304 in 2024 (Electricity Authority, review of winter 2024). Then the rain came: Meridian reported its highest hydro inflows since 1998 in the year to June 2026, and Benmore averaged $58 from January to September 2026, 69 percent below the same months a year earlier.

The islands have split: from July to September 2026 Benmore averaged $43 against $65 at Otahuhu; on 7 September South Island hydro storage stood at 178 percent of average and the North Island's at 79 (Meridian). Forward prices followed the spot market down: the ASX calendar 2027 contract at Benmore settled at $100 a MWh on 2 October 2026, 28 percent below its 1 April price of $139. $100 a MWh is 10 cents a kWh.

How wholesale prices reach your bill

On a plan that passes the spot price through, the half-hourly price lands on your bill straight away, and every $10 a MWh is a cent a kWh before network losses. On a fixed-price contract the wholesale market reaches you at renewal, priced off the forward curve: Meridian said in July 2026 that falling forward prices were already lowering commercial prices as contracts came up for review. From 1 July 2026 the Electricity Authority requires the largest retailers to offer time-varying plans, and the four large generator-retailers to sell hedges to other retailers without favouring their own retail arms.

What it means for solar

Solar saves the part of the bill charged per kWh: the energy price plus the per-kWh lines charge. Fixed daily, capacity and demand charges stay. So rising lines charges add to what solar saves only where your lines company bills per kWh, and falling wholesale prices trim the energy part. That is why a feasibility study values solar at the per-kWh charges on your own bills, with no assumed price inflation, rather than at a forecast. The commercial solar guide has costs and payback by system size, and the calculator below gives a first estimate.