Pubblicato in: Devoluzione socialismo, Economia e Produzione Industriale, Unione Europea

Siccità. La carenza idrica riduce la possibilità di raffreddare le centrali.

Giuseppe Sandro Mela.

2022-08-16.

Bernini. Ratto di Proserpina. 001

«It is a foretaste of what may happen in winter and warns that there may well be restrictions on energy use for large consumers»

«È un’anticipazione di ciò che potrebbe accadere in inverno e avverte che potrebbero esserci restrizioni nell’uso dell’energia per i grandi consumatori»

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Nel blocco europeo le centrali elettriche furono progettate per lavorare in condizioni meteorologiche poco difformi dai valori modali. In particolare, il raffreddamento delle centrali era affidato alla disponibilità di acqua. Per le centrali elettriche non erano previsti bacini idrici ad uso dedicato, mantenuti a mo’ di riserva.

Eppure gli esempi ci sarebbero stati: le centrali elettriche russe sono progettate per lavorare di inverno a -50 °C e di estate fino a +50 °C.

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La siccità in corso nel Regno Unito e in Europa sta mettendo sotto pressione la produzione di energia elettrica. L’elettricità prodotta dall’energia idroelettrica – che utilizza l’acqua per generare energia – è diminuita complessivamente del 20%. E gli impianti nucleari, che vengono raffreddati con l’acqua dei fiumi, sono stati limitati.

Si teme che le carenze siano un assaggio di ciò che accadrà nel prossimo inverno. Nel Regno Unito, le alte temperature stanno colpendo la produzione di energia da fonti fossili, nucleari e solari. Questo perché la tecnologia delle centrali elettriche e dei pannelli solari funziona molto meno bene alle alte temperature.

L’Italia ricava circa 1/5 della sua energia dall’idroelettrico, ma negli ultimi 12 mesi la produzione è diminuita di circa il 40%. Una storia simile si registra in Spagna, dove la quantità di elettricità generata è diminuita del 44%. Le cifre non sono in calo solo in una parte dell’Europa, spiega, ma tutti i grandi Paesi produttori di energia idroelettrica stanno producendo meno. Anche la Norvegia sta affrontando problemi con l’energia idroelettrica. Ha avvertito che potrebbe non essere in grado di continuare a esportare energia verso Paesi come il Regno Unito se i suoi bacini idrici non saranno riempiti.

Alcuni esponenti dell’industria idroelettrica sostengono che anche la mancanza di investimenti nella modernizzazione e nelle linee di trasmissione sta causando problemi. Quest’inverno ci troveremo di fronte a un problema. E questo dovrebbe essere un campanello d’allarme per avere maggiori investimenti nelle infrastrutture per i prossimi anni.

Il clima eccezionalmente caldo sta colpendo anche la produzione di energia nucleare, soprattutto in Francia. Circa la metà dei 56 reattori della flotta sono fuori servizio, e molti sono affetti da un problema sistemico di corrosione. Quando l’acqua nei fiumi è molto bassa e molto calda, in pratica si deve interrompere il raffreddamento delle centrali nucleari.

Anche i pannelli solari subiscono un calo significativo al di sopra dei 25°C. Tutto funziona meno bene quando fa caldo. È un’anticipazione di ciò che potrebbe accadere in inverno e avverte che potrebbero esserci restrizioni nell’uso dell’energia per i grandi consumatori.

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«The ongoing drought in the UK and Europe is putting electricity generation under pressure. Electricity from hydropower – which uses water to generate power – has dropped by 20% overall. And nuclear facilities, which are cooled using river water, have been restricted»

«There are fears that the shortfalls are a taste of what will happen in the coming winter. In the UK, high temperatures are hitting energy output from fossil, nuclear and solar sources. That is because the technology in power plants and solar panels work much less well in high temperatures.»

«Italy gets around 1/5 of its power from hydro, but that’s fallen by around 40% in the past 12 months. It’s a similar story in Spain, where the amount of electricity generated is down 44%. The figures are not just down in one part of Europe, he explains, but all the big hydropower-producing countries are making less now. Norway is also experiencing challenges with hydro-electricity. It warned that it may not be able to continue to export energy to countries like the UK unless its reservoirs were refilled»

«Some in the hydro industry say that lack of investment in modernisation and in transmission lines are also causing problems. We are going to face a problem this winter. And that should be a wake-up call to have more investment in the infrastructure for the next few years»

«The exceptionally hot weather is also hitting nuclear power production, especially in France. Around half of the 56 reactors in the fleet are offline, with several affected by a systemic issue with corrosion. Once the water in the rivers is very low and very hot, basically you have to stop cooling down nuclear power plants»

«Solar panels also experience quite a significant drop off above 25C. Everything just works less well when it’s hot. It is a foretaste of what may happen in winter and warns that there may well be restrictions on energy use for large consumers»

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Climate change: Drought highlights dangers for electricity supplies

The ongoing drought in the UK and Europe is putting electricity generation under pressure, say experts.

Electricity from hydropower – which uses water to generate power – has dropped by 20% overall.

And nuclear facilities, which are cooled using river water, have been restricted.

There are fears that the shortfalls are a taste of what will happen in the coming winter.

In the UK, high temperatures are hitting energy output from fossil, nuclear and solar sources.

That is because the technology in power plants and solar panels work much less well in high temperatures.

The prolonged dry spell is putting further pressure on energy supplies as Europe scrambles for alternative sources after the Russian invasion of Ukraine.

Hydropower is an important source of energy for Europe, but the lack of water in rivers and reservoirs is now significantly reducing the ability of facilities to produce electricity.

Italy gets around 1/5 of its power from hydro, but that’s fallen by around 40% in the past 12 months.

It’s a similar story in Spain, where the amount of electricity generated is down 44%, according to data from energy researchers Rystad Energy.

“Hydropower can be quite volatile, but 40% is absolutely extreme,” says Fabian Rønningen, a power analyst with Rystad.

The figures are not just down in one part of Europe, he explains, but all the big hydropower-producing countries are making less now.

“It’s really a big impact,,” he adds.

Norway is also experiencing challenges with hydro-electricity. It warned that it may not be able to continue to export energy to countries like the UK unless its reservoirs were refilled.

Some in the hydro industry say that lack of investment in modernisation and in transmission lines are also causing problems.

“We are going to face a problem this winter. And that should be a wake-up call to have more investment in the infrastructure for the next few years,” says Eddie Rich from the International Hydropower Association.

The exceptionally hot weather is also hitting nuclear power production, especially in France. Around half of the 56 reactors in the fleet are offline, with several affected by a systemic issue with corrosion.

Those reactors that are working are often cooled with water from rivers that are now running low, while temperatures are running high.

“Once the water in the rivers is very low and very hot, basically you have to stop cooling down nuclear power plants. That’s because the water that’s released is dangerous for fish and other species in the rivers,” said Prof Sonia Seneviratne, from ETH Zurich.

The French government is now allowing some facilities to release very warm water back into the rivers, as a temporary measure.

It underlines the stresses the heat is putting on energy production. France is now making up the shortfall in electricity by importing from the UK among others.

Analysts say this is putting additional pressure on the UK system – at a time when the very warm weather is hitting production from gas and nuclear facilities.

It’s more difficult to cool the plants in the warmer weather, explains Kathryn Porter, an energy consultant with Watt-Logic.

“Solar panels also experience quite a significant drop off above 25C. Everything just works less well when it’s hot,” she adds.

The stresses in the UK system were evident this week when the National Grid triggered a capacity market notice, a technical step indicating that the safe margins for operating the grid were reduced.

Countries, including the UK and France, rely on each other’s electricity markets.

“If both French and UK systems are in stress at the same time, then nobody really knows what will happen,” Ms Porter says.

She said it is a foretaste of what may happen in winter and warns that there may well be restrictions on energy use for large consumers.