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Assomata

Hydro power plant in Central Macedonia, Greece. Approximate location 40.4738, 22.2421.

HydroCentral MacedoniaGreececonventional storage

Assomata is a 108 MW hydro power station in Central Macedonia, Greece. It is operated by Public Power Corporation SA [100%]. Based on reported annual generation of 123 GWh, it can supply roughly 35k homes. It ranks #43 of 99 Greece power plants by installed capacity. Commissioned in 1985, it is around 41 years old — long-established. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 5.9% of Greece's electricity; the national grid averages 315 gCO₂/kWh (49.7% low-carbon) (2025).

108Source-backed capacity
123GWh reported / yr
35,200homes powered
1985commissioned (~41 yrs)

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1061085.

Data status

Known data

FacilityAssomata WRI
CountryGreece · Central Macedonia WRI
Coordinates40.4738, 22.2421 WRI
FuelHydro WRI
MW installed capacity108 MW WRI source record; scope not independently normalised
OwnerPublic Power Corporation SA [100%] WRI
Commissioned1985 WRI
Technologyconventional storage WRI
GWh reported / yr123 GWh/yr WRI

Calculated from dataset

Capacity rank in country#43 of 99 calculated
Fuel-specific rank in country#15 of 18 calculated
Capacity vs country/fuel peers0.68× · 160 MW median · 18 peers calculated
Homes-powered equivalent35,200 calculated from reported generation
Climate12.0°C · HDD 2,464 derived from coordinates
Environmental severityC2 · 30/100 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.

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 L100000601755); fuel: WRI source-record fuel

In context: how this plant compares

At 108 MW, Assomata is below the median hydro plant in Greece (160 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.

Reported generation trend

2015: 216 GWh20152016: 156 GWh20162017: 123 GWh2017216 GWh

Annual generation (GWh), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by Public Power Corporation SA [100%].

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) — Northern Hemisphere, latitude 40.5°N — which shapes how much energy it can produce and how its output varies through the year.

12.0°Cannual mean temp
2,464heating degree-days (base 18°C)
301cooling degree-days (base 18°C)
590 melevation

Monthly mean temperature

J: 2 °CJF: 3 °CFM: 6 °CMA: 11 °CAM: 15 °CMJ: 20 °CJJ: 22 °CJA: 22 °CAS: 18 °CSO: 13 °CON: 8 °CND: 4 °CD22 °C

Heating degree-days here run 0% 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: 50/100 — 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 mild atmospheric environment (estimated ISO 9223 class C2 — Low), with humidity / wetness the leading environmental stress.

C2ISO 9223 corrosivity (indicative)
30/100environmental-severity index
19.7°Cseasonal temperature swing
191 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 #15 largest hydro power plant of 18 in Greece by capacity.

Greece has 18 hydro power plants in this dataset, together about 3,729 MW of capacity.

Nearby power plants

Location

Coordinates 40.4738, 22.2421 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions

What type of power plant is Assomata?

Assomata is a 108 MW source-record hydro power plant in Central Macedonia, Greece, commissioned in 1985.

How much electricity does Assomata generate?

Assomata generates about 123 GWh of electricity per year.

How many homes can Assomata power?

Its output is enough to supply roughly 35,200 homes.

Who operates Assomata?

Assomata is operated by Public Power Corporation SA [100%].

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