Cobb

Hydro power plant in Tasman, New Zealand. Approximate location -41.0861, 172.7325.

HydroTasmanNew Zealand

Cobb is a 32 MW hydro power plant in Tasman, New Zealand. It is operated by Trustpower. Based on its capacity (estimated), it can supply roughly 32,036 homes (estimated). It ranks #38 of 43 New Zealand power plants by installed capacity. Commissioned in 1914, it is around 112 years old — an older, legacy facility. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 54.8% of New Zealand's electricity; the national grid averages 93 gCO₂/kWh (88.5% low-carbon) (2025).

32MW installed capacity
32,036homes powered (est.)
1914commissioned (~112 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1000343.

Capacity vs largest hydro plants in New Zealand

Manapouri: 800 MW800ManapouriOhau A: 688 MW688Ohau ABenmore: 540 MW540BenmoreClyde: 432 MW432ClydeMaraetai: 352 MW352MaraetaiAviemore: 220 MW220AviemoreArapuni: 192 MW192ArapuniTekapo: 179 MW179Tekapo

Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Trustpower. All plants by this company →

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a temperate oceanic climate (Köppen Cfb) — Southern Hemisphere, latitude 41.1°S — which shapes how much energy it can produce and how its output varies through the year.

9.9°Cannual mean temp
2,983heating degree-days (base 18°C)
0cooling degree-days (base 18°C)
584 melevation

Monthly mean temperature

J: 15 °CJF: 15 °CFM: 14 °CMA: 11 °CAM: 8 °CMJ: 5 °CJJ: 5 °CJA: 6 °CAS: 8 °CSO: 9 °CON: 11 °CND: 13 °CD15 °C

Heating degree-days here run 21% above the median power plant in this dataset — a proxy for how much extra energy heated equipment must replace through its surfaces in winter.

Climate heat-demand index: 62/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

In colder climates, uninsulated hot equipment (boilers, turbines, valves, steam lines) loses proportionally more heat to ambient air — exactly the loss Inzonex modular insulation is designed to cut.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

How it compares & nearby plants

The #21 largest hydro power plant of 24 in New Zealand by capacity.

New Zealand has 24 hydro power plants in this dataset, together about 4,388 MW of capacity.

Nearby power plants

Location

Coordinates -41.0861, 172.7325 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Built from open public data; no personal information. Operate this site? Request a correction or removal.