Greece is mostly a mountainous country with many scattered islands. It covers an area of 132,000km2 and has a population of some 11M people (in 2001). The most mountainous parts are the western and northwestern ones. Their differences in elevations create advantageous conditions for water head development.
With such a favourable topographic relief, Greece has important hydro resources, the majority of which is located in the northwestern part of the country. This region has suitable climatic conditions (ie. abundant precipitation) as well as the most important rivers and catchment basins (Acheloos, Arachthos, Aoos, Aliakmon and Nestos rivers).
The total gross annual hydro potential, is estimated at 80GWh, 12GWh of which may be economically developed. So far, some 50% of it has already been developed.
The country’s total installed capacity amounts to some 3080MW (16 large plants and eight small ones) with an average contribution of 10% to the total annual electricity generation (mean annual net production around 5000GWh).
The general and technical characteristics of Greece’s 16 large hydro plants are illustrated in tables 1 and 2.
The reservoir of Gratini dam in Thrace will supply cooling water to the Komotini thermal plant (combined cycle), now being completed. The dam is a 42m high, rockfill type with an impervious central clay core and a volume of 1.7Mm3. The created reservoir has an area of 850,000m2 and a 12.8 x 106m3 storage capacity.
In parallel, four plants (ie. hydro dams) are under construction. See table 3.
The Messochora plant, under construction, has been considerably delayed due to land expropriation problems regarding areas inundated by the created reservoir. The Temenos plant, though tendered two years ago, has not been contracted yet.
In Greece hydro plants meet peak energy demands and most of them are planned as multi-purpose plants, ie. meeting irrigation and water supply needs of the neighbouring land areas.
The future of Greek hydro power seems rather obscure, since no other other hydro schemes – beyond those already mentioned – are being planned, and private investors do not seem willing to build large hydro schemes.