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Matahina

Hydro power plant in Bay of Plenty, New Zealand. Approximate location -38.1141, 176.8162.

HydroBay of PlentyNew Zealandconventional storage

Matahina is a 80 MW hydro power plant in Bay of Plenty, New Zealand. It is operated by Trustpower. Based on its capacity (estimated), it can supply roughly 80k homes (estimated). It ranks #30 of 50 New Zealand power plants by installed capacity. Commissioned in 1967, it is around 59 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).

80Source-backed capacity
80,091homes powered (est.)
1967commissioned (~59 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1000339.

Data status

Known data

FacilityMatahina WRI
CountryNew Zealand · Bay of Plenty WRI
Coordinates-38.1141, 176.8162 WRI
FuelHydro WRI
MW installed capacity80 MW WRI source record; scope not independently normalised
OwnerTrustpower WRI
Commissioned1967 WRI
Technologyconventional storage WRI

Calculated from dataset

Capacity rank in country#30 of 50 calculated
Fuel-specific rank in country#14 of 24 calculated
Capacity vs country/fuel peers0.89× · 90 MW median · 24 peers calculated
Homes-powered equivalent80,091 calculated
Climate11.9°C · HDD 2,230 derived from coordinates
Environmental severityC4 · 34/100 derived from coordinates

Not available

GWh reported / yrNot available not in dataset
CO₂ emissionsnot applicable not applicable

Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.

Capacity provenance

The public capacity above is the current source-record value. A 2026 tracker candidate lists 80 MW for Matahina hydroelectric plant, but it is not used as the public primary value until scope is verified (unit vs operating vs installed/project total).

Capacity claim grade: A2_GENERAL_REVIEW - recommended action: manual_source_check - confidence: medium_low. This follows a claim-based data model: value + scope + source + confidence, rather than silently overwriting records.

Data provenance

The capacity and/or fuel fields on this page include a source-backed provenance label from GEM, an official registry, Wikidata, OSM, or a cross-source match.

capacity: GEM tracker 2026 (location L100000604280); fuel: WRI source-record fuel

In context: how this plant compares

At 80 MW, Matahina is below the median hydro plant in New Zealand (90 MW). Technically it is described as conventional storage. Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Capacity vs largest hydro plants in New Zealand

Manapouri: 800 MW800ManapouriOhau A: 688 MW688Ohau ABenmore: 540 MW540BenmoreClyde: 432 MW432ClydeMaraetai: 360 MW360MaraetaiAviemore: 220 MW220AviemoreTekapo: 179 MW179TekapoArapuni: 164 MW164Arapuni

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

Owner

Operated by Trustpower.

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 38.1°S — which shapes how much energy it can produce and how its output varies through the year.

11.9°Cannual mean temp
2,230heating degree-days (base 18°C)
0cooling degree-days (base 18°C)
394 melevation

Monthly mean temperature

J: 17 °CJF: 17 °CFM: 16 °CMA: 13 °CAM: 10 °CMJ: 8 °CJJ: 7 °CJA: 8 °CAS: 9 °CSO: 11 °CON: 13 °CND: 15 °CD17 °C

Heating degree-days here run 9% below 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: 47/100 — this site sits in the mid third of the power plants we cover by heating degree-days.

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.

Site climate & environmental severity

For a plant’s outdoor hardware — heat-recovery steam generators (HRSG), expansion joints, valves, flanges and their insulation — the local climate sets how fast unprotected steel and coatings degrade. This site sits in a corrosive environment (estimated ISO 9223 class C4 — High), with humidity / wetness the leading environmental stress.

C4ISO 9223 corrosivity (indicative)
34/100environmental-severity index
10.0°Cseasonal temperature swing
40 kmdistance to coast

Higher environmental severity is exactly where protective removable insulation pays back most: a sheltered micro-climate slows corrosion, UV and thermal-cycling damage and extends outdoor hardware service life. This is an indicative site-climate context — not a condition assessment of any specific plant or operator.

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #14 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 -38.1141, 176.8162 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Matahina?

Matahina is a 80 MW source-record hydro power plant in Bay of Plenty, New Zealand, commissioned in 1967.

How many homes can Matahina power?

Its output is enough to supply roughly 80,091 homes (estimated).

Who operates Matahina?

Matahina is operated by Trustpower.

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