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Waitaki

Hydro power plant in Otago, New Zealand. Approximate location -44.6747, 170.3989.

HydroOtagoNew Zealandconventional storage

Waitaki is a 90 MW hydro power plant in Otago, New Zealand. It is operated by Meridian Energy. Based on its capacity (estimated), it can supply roughly 90k homes (estimated). It ranks #28 of 50 New Zealand power plants by installed capacity. Commissioned in 1935, it is around 91 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).

90Legacy source-record capacity
90,102homes powered (est.)
1935commissioned (~91 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1000303.

Data status

Known data

FacilityWaitaki WRI
CountryNew Zealand · Otago WRI
Coordinates-44.6747, 170.3989 WRI
FuelHydro WRI
MW installed capacity90 MW WRI source record; scope not independently normalised
OwnerMeridian Energy WRI
Commissioned1935 WRI
Technologyconventional storage WRI

Calculated from dataset

Capacity rank in country#28 of 50 calculated
Fuel-specific rank in country#12 of 24 calculated
Capacity vs country/fuel peers1.00× · 90 MW median · 24 peers calculated
Homes-powered equivalent90,102 calculated
Climate9.1°C · HDD 3,256 derived from coordinates
Environmental severityC3 · 26/100 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 105 MW for Waitaki 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_MEDIUM_REVIEW - recommended action: manual_source_check - confidence: medium. This follows a claim-based data model: value + scope + source + confidence, rather than silently overwriting records.

Data provenance

The capacity and fuel fields on this page are source-record values from the upstream open dataset. They are useful for identification and ranking, but they have not been upgraded to a 2026 registry/GEM-location verified value.

capacity: WRI Global Power Plant Database source-record (legacy); fuel: WRI source-record fuel

In context: how this plant compares

At 90 MW, Waitaki is around 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 Meridian Energy. 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 44.7°S — which shapes how much energy it can produce and how its output varies through the year.

9.1°Cannual mean temp
3,256heating degree-days (base 18°C)
0cooling degree-days (base 18°C)
558 melevation

Monthly mean temperature

J: 15 °CJF: 14 °CFM: 13 °CMA: 10 °CAM: 6 °CMJ: 4 °CJJ: 3 °CJA: 4 °CAS: 7 °CSO: 9 °CON: 11 °CND: 13 °CD15 °C

Heating degree-days here run 32% 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: 70/100 — this site sits in the top 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 moderately corrosive environment (estimated ISO 9223 class C3 — Medium), with humidity / wetness the leading environmental stress.

C3ISO 9223 corrosivity (indicative)
26/100environmental-severity index
11.6°Cseasonal temperature swing
71 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 #12 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 -44.6747, 170.3989 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Waitaki?

Waitaki is a 90 MW source-record hydro power plant in Otago, New Zealand, commissioned in 1935.

How many homes can Waitaki power?

Its output is enough to supply roughly 90,102 homes (estimated).

Who operates Waitaki?

Waitaki is operated by Meridian Energy.

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