Hydropower is already pervasive in the Alps, providing about 100 terawatt hours per year (TWh/a) of power in the region. There are many potential places in the Alps for more hydropower plants. But how much would it cost to build them and the necessary infrastructure to transfer their energy to the grid? And, moreover, how much would increasing hydropower capacity impact the environment and ecosystem services?
In theory, the hydropower potential can still increase. Calculations from EURAC’s physical model have shown a total theoretical potential of 180TWh/a. Assuming that no new power stations would be built on existing sites, the technical potential represents some 80TWh/a. Restricting the construction of new power stations outside protected areas such as natural and regional parks, nature reserve, particular protection, Natura 2000, UNESCO biosphere reserve or world heritage sites, the technical potential is reduced to an environmental potential of less than half – down to 35TWh/year. But the tradeoffs in plant size have to be explored: large hydropower plants produce more energy and are more cost-effective, but they also might have a large impact on the environment.
Smaller plants, in contrast, are more expensive for the amount of energy they produce, but usually have less of an impact on the environment. In some cases, though, even the environmental impact of small scale hydro plants is substantive. IIASA researchers further analyzed the results from EURAC in their techno-economic model for renewable energy optimization “BeWhere” (www.iiasa.ac.at/bewhere) in order to identify the economic potential. The results from BeWhere indicate that in a business-as-usual scenario, a mixture of smaller and larger hydro-power stations spread over the Alpine countries might reach some 10TWh/a.
However, if a more stringent policy (i.e. carbon tax) were introduced in all seven Alpine countries, the spatial distribution and capacities of the potential power plants appear to be highly sensitive to such policy and the potential (additional) production might stay clearly below this 10TWh/a.
I presented the potential for hydropower in the Alps at the World Water Week in Stockholm in Stockholm, Sweden in September 2014. Watch a video of the session on the World Water Week Web site.