Dry summer could curb generation not only at hydropower plants and push up electricity prices

If June rainfall does not improve water reserves, hydropower generation could fall significantly, a representative of the Italian hydropower producers’ association told energy news outlet Montel. Water reserves have already been substantially depleted, as snowpack levels are unusually low for this time of year. Low water reserves—and low river levels—are also causing problems for other types of power plants.

Drought is affecting Europe

A UN report from earlier this year warns that a “water crisis” is looming and that a range of measures must be taken to reduce water consumption or improve water management. Water scarcity is also having a significant impact on Europe’s energy sector.

“The snow reserves that are usually still present at this time of year in the Alps or the Apennines are gone, as they have already melted,” Paolo Taglioli of the Italian association said in an interview. “We don’t have water everywhere, and what’s more, we don’t have the snow reserves needed to guarantee Italy a smooth transition into the autumn months, when we hope to see more precipitation.”

Hydropower has low variable costs and is therefore a source of cheap energy once the plants have been built. If total precipitation across Italy in June is below the long-term average, Taglioli says this will mean lower generation and higher electricity prices, as power plants with higher production costs will need to be brought online.

Hydropower has accounted for around 14.1% of Italy’s electricity generation since the beginning of the year, with output of 10.7 TWh. Generation is, however, at risk from the threat of prolonged drought in the future. Examples include plants operated by Eni, Edison and others in northern Tuscany.

As Montel notes by way of context, annual hydropower output is typically around 45 TWh, while net electricity consumption stands at around 300 TWh.

Low river levels restrict generation from other sources too

Drought and the resulting lower river levels, seen in many European countries in recent years, also complicate generation at conventional power plants. River water is often used to cool thermal power plants.

When rivers are used for cooling, a maximum temperature is set for the watercourse at the point where cooling water is discharged. Because river water is warmer when levels are lower (a smaller volume of water heats up more quickly), power plants have less cooling capacity, which can force them to reduce output or shut down. Examples include Hungary’s Paks power plant and some French nuclear power plants.

Low river levels also make it harder to transport coal by river. Operators are forced to seek alternative transport to keep power plants running when rivers are not navigable. This situation is often seen at power plants along the Rhine.