Business power on NZ's West Coast: how Westpower and Buller Electricity charge commercial connections, what's pushing costs up, and the discounts paid back.
Quick answer
Two consumer-trust-owned lines companies serve almost all of the West Coast: Buller Electricity from Karamea to just north of Punakaiki, and Westpower from Lyell to Paringa. Neither is under Commerce Commission price control. For businesses, the main cost drivers are capacity and peak-demand charges, rising Transpower transmission costs, and whatever discount your network pays back.
Lines network
Westpower · Buller Electricity
Main business centres
Greymouth · Westport · Hokitika · Reefton · Franz Josef · Karamea
Two lines companies split almost all of the Coast between them. Both are owned by consumer trusts, and both are exempt from Commerce Commission price control.
| Network | Area | Consumers | Owner |
|---|---|---|---|
| Buller Electricity | Karamea south to Meybille Bay (5 km north of Punakaiki), including Westport | about 5,000 | Buller Electric Power Trust |
| Westpower | Grey and Westland districts and part of Buller, from Lyell to Paringa, including Reefton, Greymouth, Hokitika, Franz Josef and Fox Glacier | about 14,600 | West Coast Electric Power Trust |
Haast, south of Paringa, is beyond the national grid and relies on a local hydro scheme on the Turnbull River. Everywhere else, your retailer can confirm which network your ICP is on.
Both are small networks stretched over a lot of ground. Westpower's 14,600 consumers are spread across 18,017 square kilometres. On Commerce Commission figures that is about 6.7 (Westpower) and 7.7 (Buller Electricity) connections per kilometre of line, against more than 30 on Auckland's Vector network. Westpower lists what pushes its costs up: long feeders need an unusually high number of zone substations, severe salt-air corrosion calls for marine-grade components, and distance from the grid makes transmission 15.2% of its line charges.
The two networks build their lines charges quite differently.
Westpower's own table of average revenue change for 2026/27 shows:
Those figures include growth in consumption, and for large load also in customer numbers and capacity, so your own bill may have moved differently. Urban and rural customers pay the same tariff rates. Westpower also reports major load growth in rural areas where mining is increasing, which it says calls for strong pricing signals.
Buller Electricity kept delivery prices unchanged for standard customers in 2026/27. Its trust owners accepted a lower return to absorb a $307,000 rise in transmission costs.
Non-residential connections above 15 kW, and dairy farms, pay a capacity charge set by their highest half-hour demand in the 12 months to 31 August, applied from the following 1 April. For 2026/27, Buller rolled last year's figures over unchanged. Dairy milking sheds make up about 40% of the load on its rural 11 kV network, and since 2021 they have had their own price category.
Westpower's board will return $5.5 million to consumers as a lines-charge discount for 2026. It is passed to retailers and shows on power accounts in December 2026. Small and medium businesses sit in the group that gets $15 per consumer plus a share based on consumption in the year to 30 September 2026.
Buller Electricity has no set discount policy. Any discount or rebate is a board decision made with its trust owners.
Peak demand on Westpower's network is about 44 MW. Up to 28 MW is generated on the Coast by small hydro schemes (there are ten), including the Amethyst run-of-river scheme Westpower commissioned in 2013. The rest comes from the national grid.
In April 2026 the 23 MW Waitaha hydro scheme in South Westland received all its fast-track approvals. It is a partnership between Westpower and Poutini Ngāi Tahu and would produce 120–140 GWh a year, which Westpower puts at about half the Coast's electricity needs. The scheme would cost around $200 million and still needs geotechnical work, detailed design and a final investment decision.
On 29 December 2025, a fault at Buller Electricity's Robertson Street substation in Westport cut power across a large part of the district. Westpower notes that three of the Coast's hydro schemes, Amethyst, Wahapo and Fox, can run independently during outages.
Much of Buller's network is rural, with significant dairy and other farming. The Stockton opencast coal mine is a major electricity user.
EECA's 2023 West Coast study covered 21 large process-heat sites in the dairy, meat, industrial and commercial sectors, with most of the region's emissions from coal. Its lowest-cost pathway had electricity meeting 40% of those sites' energy needs as they switch fuels. Gas in the South Island means LPG (why gas costs are rising), so electrification lands on these two small networks.
Manage My Bills reviews commercial connections nationwide (why location changes the price). On the Coast, demand rules set much of a larger site's lines charge, so send us your bills with your half-hour data if you have it.
Buller Electricity covers the coastal Buller District from Karamea south to Meybille Bay, including Westport. Westpower covers the Grey and Westland districts and part of Buller, from Lyell to Paringa, including Reefton, Greymouth, Hokitika, Franz Josef and Fox Glacier. Haast, south of Paringa, is beyond the national grid and relies on a local hydro scheme.
Not for standard customers. Buller Electricity kept delivery prices unchanged for 2026/27, and its trust owners accepted a lower return to absorb a $307,000 rise in transmission costs.
Large, bulk and Otira connections stay on capacity and peak-demand pricing. Peak demand is the average of your top twelve half-hours in each billing month, so short spikes cost money. General and medium connections with smart meters moved to day/night pricing on 1 April 2026.
It should. Westpower passes each consumer's share to retailers, and it appears on power accounts in December 2026. The $5.5 million is split between small and larger customer groups in proportion to the income each group provides.
Primary sources first. Every figure on this page comes from one of these, each with the date we last accessed it.
Last updated by the Manage My Bills Energy Team.
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