Business power in Marlborough, NZ: how Marlborough Lines prices capacity, peak hours and demand, what it means for wineries, and how its annual discount works.
Quick answer
Every business in Marlborough sits on one network, Marlborough Lines, which is consumer-trust owned and outside Commerce Commission price control. What you pay for delivery depends on your connection's capacity, weekday peak-hour use and, for large sites, your highest demand over three years, partly offset by an annual discount credited through your retailer.
Lines network
Marlborough Lines
Main business centres
Blenheim · Picton · Renwick · Havelock · Seddon · Ward
One company: Marlborough Lines. It looks after a network area of 11,330 square kilometres that takes in plains, coastline, rivers, rugged mountains and the Marlborough Sounds. The Marlborough Electric Power Trust holds all its shares on behalf of the people connected to the network. Because it is consumer-owned, the Commerce Commission exempts it from price-quality regulation: there is no regulated price path, only information disclosure.
It is a long, thin network. On Commerce Commission figures for the year to March 2025, Marlborough Lines served about 27,200 connections over roughly 3,560 km of line. That is about 7.6 connections per kilometre, against more than 30 on Auckland's Vector network. Remote connections, such as those in the Marlborough Sounds, are costly to maintain, which is why Marlborough Lines prices them in separate categories. And the whole region takes its supply from Transpower through three circuits to a single grid exit point at Springlands, in Blenheim.
How lines charges are built varies from network to network. In Marlborough, it depends on your connection's size (its capacity in kVA) and your meter.
| Your connection | How the lines charge is built |
|---|---|
| General, up to 150 kVA | Daily fixed charge by capacity band (up to 15, 16–30, 31–50, 51–70, 71–105 or 106–150 kVA) plus a per-kWh charge |
| General with a communicating smart meter, not remote | Time-of-use energy: peak 7am–11am and 5pm–9pm weekdays, off-peak at all other times including weekends |
| Remote and extreme-remote areas | Separate non-time-of-use categories reflecting the cost of long lines |
| Irrigation pumps | Fixed charge by pump size, charged all year, so you can't disconnect for the off-season |
| Commercial and industrial, over 150 kVA | Half-hourly metering, a fixed connection charge, a capacity charge and a transmission charge (both per kVA per day), and day/night energy |
For bigger sites, two rules work like demand charges. First, the capacity charge uses the highest monthly demand seen over the previous three full years (averaging your six highest half-hours each month). It generally won't fall below 60% of a dedicated transformer's capacity (54% for a dedicated 500 kVA transformer). Second, the transmission charge resets every 1 April based on your average monthly peak over Transpower's pricing year (1 September to 31 August), with a 50 kVA minimum. One unmanaged spike, with everything starting at once, can set your capacity charge for three years.
Marlborough is by far the country's largest wine region, with 32,191 hectares or 73% of New Zealand's planted vineyard area. On the network, that shows up as irrigation pumping. Marlborough Lines runs dedicated irrigation price categories, including ones for connections using capacity added by its network upgrade in the upper Wairau Valley.
If your business has a seasonal peak, such as a winery at vintage, a packhouse or a pump shed, the capacity and demand rules above can matter more than the cents-per-kWh rate on your bill. We cover the wider energy picture for food producers and processors separately.
Transpower's transmission charges for Marlborough rose by more than $1.6 million, or 23%, in the 2025/26 year. Lines charges pass those costs straight through.
Marlborough Lines is also building its own generation through its subsidiary Energy Marlborough, which notes that the region's electricity is "predominantly transmitted from South Canterbury", with losses along the way. It has commissioned several solar farms:
In April 2025 it also bought the Weld Cone and Lulworth wind farms just south of Ward, which have seven 250 kW turbines between them.
As a consumer-owned network, Marlborough Lines pays an annual discount. It is paid to your retailer, which credits your account. The 2026 payment went onto accounts through May. The average eligible household connected for the full year received $283 including GST. Business amounts vary with connection type, days connected and consumption. Up to 10% of connections, typically remote ones, don't receive it.
When you compare electricity offers, treat that credit separately. It comes from the lines company whichever retailer you use.
Manage My Bills reviews commercial connections nationwide from our Manukau office, including how location changes a commercial power price. If you run a winery, packhouse or other Marlborough site over 150 kVA, send us your bills and ask about your capacity history first.
Marlborough Lines. Its network covers 11,330 square kilometres, from Blenheim out to the Marlborough Sounds. It is the only lines company in the region, so it can't be switched; the retailer selling you the energy can.
Most connections do. The amount depends on your connection type, the days you were connected and your consumption over the year, and it is paid to your retailer to credit to your account. Up to 10% of connections, typically ones Marlborough Lines classes as remote, don't receive it.
For general (small and medium business) connections on time-of-use pricing, peak is 7am to 11am and 5pm to 9pm on weekdays. All other times, including weekends, are off-peak. Connections over 150 kVA are billed on day (7am to 11pm) and night energy plus capacity and transmission charges.
For connections over 150 kVA, Marlborough Lines averages your six highest half-hour demands each month and sets your chargeable capacity at the highest monthly figure over the previous three full years. A new peak resets that level for the following three years.
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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