Hydroelectric power in Italy

In Italy, hydroelectric power is the oldest form of renewable energy; in fact, it has its roots in the last years of the nineteenth century, a period in which Italy represented the world’s avant-garde country in the development of hydraulic systems capable of obtaining clean energy. For years, in the twentieth century, it was even thought that with hydroelectric it was possible to achieve energy self-sufficiency for the entire country. The first power plant was inaugurated in 1895 in Paderno d’Adda, in the province of Lecco, and to date, according to a 2019 Terna calculation, there are about 4,401 throughout the country, mostly in the Alps and Apennines. Golden years for the construction of plants were 2010 (+480 plants), 2016 (+270), and 2017 (+348); However, the growth in number has not been matched by an equal increase in the power generated, but the average size of the plants themselves has decreased. This phenomenon is explained by the advent of mini-hydroelectric, i.e. the installation of small plants, which involves the use of smaller, safer structures with a low environmental and landscape impact. The installation of these plants began in the early 2000s, so much so that the overall average size of the national plants went from 8.4 megawatts to about 4.4 megawatts in the first decades.

In Italy, hydropower is not evenly distributed. In fact, most of the lifts are located along the Alps. At the end of 2018, the following plants were registered:

• Piedmont: 930 plants, corresponding to 14.6% of the national figure in terms of power
• Lombardy: 661 plants, corresponding to 27.2% of the national figure in terms of power
• Trento and Bolzano Autonomous Province: respectively with 268 and 543 plants, together they represent 19.3% of the national power
• Veneto: 392 plants and 6.2% of national power
• Aosta Valley: 173 plants and 5.2% of national power
• Friuli-Venezia Giulia: 233 plants and 2.8% of national power
• Abruzzo, with only 71 plants but 5.4% of the national power
• Calabria: 54 plants and 4.1% of national power
• Umbria: 45 plants and 2.8% of the national power
• Liguria, Molise, Puglia, Basilicata, and Sicily collect 2.5% of the total installed power

If we go down from the regional scale to the provincial one, there is a certain inhomogeneity also at the local level. In Lombardy, Brescia and Sondrio each have 11.9% of the national power, while Pavia, Lodi, and Cremona have just 0.1%. And in addition to the aforementioned Trento and Bolzano, Turin (5.8%) and Aosta (5.2%), as well as Cuneo (3.5%) and Belluno (3.3%) stand out for productivity in their most mountainous part. In the center-south and on the islands, however, the provinces with relatively higher values are Teramo (3.0%), Terni (2.6%), Cosenza (1.9%) and Nuoro (1.9%).

At the end of 2018, according to the data collected by GSE, Gestore dei Servizi Energetici, Italy has a total installed capacity for hydropower of 18.94 gigawatts, a value that corresponds to more or less 35% of the national power from green sources. In addition, in terms of produced energy, hydroelectric power has reached 48.8 TW/h, equal to just over 15% of national energy needs and 43% of production from renewable sources. The large Italian plants, i.e. with a power of more than 10 megawatts, are about 308 and produce three quarters of the total energy alone, while the more than 3000 small plants, i.e. with a power of less than one megawatt, contribute about 308 6%. The fluctuations in energy produced from one year to the next are determined on the one hand by meteorological factors and, on the other, by new installations or decommissioning of large plants. Rather regular, however, is the geographical distribution of the energy produced: 80% comes from the northern regions, and the remaining part is equally divided between center and south, with just over a percentage point of advantage in favor of the southern regions.

According to the report, Italy is currently one of the countries with the lowest energy autonomy in Europe, producing only 22.5% of the energy consumed in its territory, compared to a European average of 39.5%. In comparative terms, Italy is fifth last in the EU but, at the same time, it is second in the EU for the availability of renewable energy sources and is counted among the most virtuous countries in terms of improving energy autonomy, having increased its level by 9 percentage points between 2000 and 2019. This growth is attributable to the development of renewable energy sources present in the area and further exploitable. In addition, a study by Althesys, a company specialized in economic research and strategic consulting in the environment, energy, infrastructure and utilities sectors, estimated that with the technological renewal of just one third of Italian plants, the energy generated annually could be increased by almost 10%, already by the end of the twenties of the century.

Italian hydroelectric energy does not seem to foresee exponential growth in its future like other Greek sources, but the development prospects are many and interesting. Today, technology and innovative solutions make it possible to transform almost all the energy of water into electricity, with values of 70%-75% chand can reach over 80%. If for large plants it is difficult to think that there can be significant variations, an interesting perspective is that of the aforementioned mini-hydroelectric. The increase in small plants, even for self-production, is a sign of a growing sector from which to draw energy and economic benefits.
Given that most of the large Italian plants are dated (more than 70 years of life in operation), the energy actually obtained is affected by three factors:

• the signs of aging,
• failure to modernise facilities,
• lower hydroelectric potential due to climate change

The renewal of the plants, even with maintenance interventions and small replacements, is estimated to gain at least 5.8 gigawatts of power and 4.4 terawatt hours of annual energy in just a few years, with a saving of over 2 million tons of carbon dioxide. Finally, although hydroelectric power is an absolutely green source, the presence of plants can impact on the environment, and therefore it is necessary to find solutions that do not negatively affect the landscape and local fauna, so that the plants are increasingly integrated into the natural context.