Coghinas hydropower plant
The Coghinas hydropower plants in northern Sardinia is a Guiness record complex. The recent celebrations for the 90 years since the construction of the dam and the entry into service of the facilities on the 240-cubic metre Coghinas artificial lake did not only mark a historic milestone for this great engineering work. They also - and most of all - acclaimed an example of efficiency that is rare in the energy field. When in 1991 a single vertical-axis Francis turbine replaced the three original horizontal-axis generators with a capacity of 22 MW, hardly anybody expected it to keep up its faultless performances beyond the 15 years of operations.
However, beyond all forecasts, the plants kept on working for another decade with an average of 4,000 hours per year, without requiring any extraordinary maintenance.
In service for at least another 20 years
With the overhaul carried out by Enel’s Hydro Business Sardinia, supported by the chain unit O&M Hydro, the Coghinas hydro complex at the Muzzone dam will be able to operate for at least 20 more. Not bad for a project born under the difficult economic conditions of Fascist Italy when, given the shortage of natural resources, Mussolini hailed its opening on 20 December 1926 as a bold step of the Società Elettrica Sarda towards Italy’s self-sufficiency in the energy field.
“At a time in which the efficient use of resources is key for being competitive and meeting specific targets, the overhaul of Coghinas was an excellent ground to test the effectiveness of this approach”
– Renato Giardina, Head of the Business Hydro Sardinia Unity
"This is an amazing achievement both from the point of view of reliability - said the Head of Business Sardinia O&M Large Hydro Renato Giardina, - and of Enel's approach, capable of maximising the use of its resources over external ones. Thanks to the perfect synergy between the different business units, the overhaul was completed in six months, putting back into service, a facility that can produce 70,000 MW per year for 25,000 households, with a reduction rate of CO2 emissions of around 45,000 kilos".
Great respect for environmental resources
The environmental focus is confirmed as a key priority for the Sardinian complex, given that its 1,740-km2 basin has strategic value also for agriculture and tourism: every year the 58-metre high dam, with a crest length of 158 metres, provides 80/90 million cubic metres of water, while protecting the fish.
In fact, a project carried out with the Province of Olbia Tempio involves fish ladders to facilitate the reproduction of eels, allowing them to continuously move between the reservoir and the bed of the river Coghinas. In addition, the contribution of the Oschiri (Sassari) town hall was essential, since by widening the road that leads to the plant it has enabled to speed up the disassembly and reassembly of overhauled components.
“Keeping up our high professionalism and specialisation in the future must be a constant and profitable practice”
– Michele Maranci, Head of Hydro Central Maintenance & ET Support
"The big plus of this project - said Michele Maranci, head of Hydro Central Maintenance & Elecromechanical Technical Support of O&M Large Hydro - consisted in having fostered a dynamic organisation, geared to the real needs and avoiding overlaps in the specialisations. In fact, by means of this job rotation skills and experience are transferred, so that thanks to the osmosis between the business unit directions and the O&M Hydro technical structures we will be able to our manage our business increasingly well".