Hydropower Potential in the Alps under Climate Change Scenarios. The Chavonne Plant, Val D’Aosta

Abstract

Present and prospective climate change will likely affect the hydrological cycle in sensitive areas, such as the Alps, thus impacting water-based activities. A most representative example is hydropower production, i.e., exploitation of water to produce energy. In the Italian Alps hydropower is strictly dependent upon water from snow and ice melt, and both are decreasing in response to global warming. Here, we study the effects of potential climate change scenarios at 2100 upon hydropower production from the Chavonne plant, in Valle d’Aosta region of Italy, a run-of-the-river (ROR) plant taking water from two high altitude glacierized catchments of Val di Cogne, and Valsavarenche. We use Poli-Hydro, a state-of-the-art hydrological model to mimic the hydrological budget of the area, including ice and snow melt share. Projections of the hydrological budget were built until 2100 by means of selected climate change scenarios, under proper downscaling. We used runs of three General Circulation Models (GCMs), EC-Earth, CCSM4, and ECHAM6.0 under three Representative Concentration Pathways RCP 2.6, RCP 4.5, and RCP 8.5 from AR5 of IPCC, and of their updated version under four Shared Socio-Economic Pathways SSP1 2.6, SSP2 4.5, SSP3 7.0, and SSP5 8.5 from AR6. We then assessed hydropower production changes against a recent control run CR period (2005–2015). Mean annual flow is estimated at 14.33 m3 s−1 during CR, with ice melt contribution ca. 2%, and snow melt contribution ca. 44%. Ice cover in 2005 was estimated as 19.2 km2, reaching in 2015, 9.93 km2. Mean hydropower production was estimated at 153.72 GWh during the CR. Temperature would largely increase throughout the century (+0.93 °C on average at the half century, +2.45 °C at the end of the century). The ice covered area would be largely depleted (ca. −86%, −94% respectively), with reduced contribution of ice melt (0.23%, <0.1%, respectively) and snow melt (ca. 37%, 33%, respectively). Precipitation would show uncertain patterns, and hence incoming discharge at the plant would erratically vary (−29% to +24% half century, −27% to +59% end of century). Hydropower production displays a large dependence upon monthly discharge patterns, with mostly positive variations (+2.90% on average at half century, +6.95% on average at end of century), with its change driven by exceedance of plant’s capacity.

Challenges in the Development of Hydropower in Selected European Countries

“…Research has shown that this impact depends on the region and hydrological characteristics [89,90]. The most vulnerable areas are mountain areas, which are dependent on glacial water [91], as well as desert areas (e.g., the Middle East) [92] or the Mediterranean climate [93]. Running water is also more at risk than standing water due to its inability to store water [94].…”

“…There are countries that, despite high water resources, are no longer able to build new hydropower plants due to their unprofitability [112]. For example, Alpine countries have the technology and resources to implement new projects, but lack water resources available that are profitable for hydropower development [91]. This is most often the case in Europe and North America, where 75% and 69% of the hydropower potential is used, respectively [103].…”

Lost Energy of Water Spilled over Hydropower Dams

“…The reason we assessed these losses is in the character of the Sava River, which is a typical sub-Alpine river [16]. Flood events are more frequent in the Spring, when the snow melts in the Alps, and in Autumn when heavy rainfalls occur.…”

Economic Sustainability of Small-Scale Hydroelectric Plants on National Scale – The Italian Case Study

“…provided a synthesis and comparison of methodologies and results obtained in several studies devoted to the impact of climate change on hydropower on Swiss and Italian Alps [12]. Duratorre et al (2020) studied the effects of potential climate change scenarios at 2100 upon hydropower production from the Chavonne plant, in Valle d'Aosta region of Italy, using Poli-Hydro, a state-of-the-art hydrological model to mimic the hydrological budget of the area, including ice and snow melt share [13]. Patro et al (2018) assessed the impacts of nine climate-change scenarios on the hydrological regime and on hydropower production of forty-two glacierized basins across the Italian Alps, for the period 2016-2065.…”