LOWER METTUR is a 120 MW hydro power station in Tamil Nadu, India. It is operated by Tamil Nadu Power Distribution Corp Ltd [100%]. Based on reported annual generation of 219 GWh, it can supply roughly 63k homes. It ranks #809 of 2,229 India power plants by installed capacity. Commissioned in 1988, it is around 38 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 8.6% of India's electricity; the national grid averages 670 gCO₂/kWh (26.7% low-carbon) (2025).
Plant data: WRI Global Power Plant Database (CC BY 4.0), id IND0000238.
Known, modelled and calculated values are kept separate. Missing fields are shown as unavailable.
The public capacity above is the current source-record value. A 2026 tracker candidate lists 30 MW for Lower Mettur II 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: D_REJECT_KEEP_MASTER - recommended action: keep_master - confidence: rejected_candidate. This follows a claim-based data model: value + scope + source + confidence, rather than silently overwriting records.
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
At 120 MW, LOWER METTUR is well above the median hydro plant in India (80 MW). Technically it is described as run-of-river. 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.
Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).
Operated by Tamil Nadu Power Distribution Corp Ltd [100%].
This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a tropical savanna climate (Köppen Aw) — Northern Hemisphere, latitude 11.6°N — which shapes how much energy it can produce and how its output varies through the year.
Monthly mean temperature
This site has effectively no heating season (tropical/equatorial climate), so winter heat loss is not the driver here. The thermal concern shifts to year-round process heat and humidity/heat-driven corrosion of hot equipment.
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.
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.
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.
The #89 largest hydro power plant of 233 in India by capacity.
India has 233 hydro power plants in this dataset, together about 45,527 MW of capacity.
Coordinates 11.6425, 77.7583 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.
LOWER METTUR is a 120 MW source-record hydro power plant in Tamil Nadu, India, commissioned in 1988.
LOWER METTUR generates about 219 GWh of electricity per year.
Its output is enough to supply roughly 62,628 homes.
LOWER METTUR is operated by Tamil Nadu Power Distribution Corp Ltd [100%].
