Commentary: Heatwaves and jellyfish are causing the grid to wilt

SYDNEY: It’s not just people who struggle to perform effectively when the temperature starts to soar. The electricity system we depend on to keep us cool is having the same problem.

A swarm of jellyfish linked to unusually warm waters in northern Europe caused French utility Electricite de France to shut two nuclear power stations this week, after the invertebrates clogged up parts of their cooling systems. Other reactors in the country may have to cut output because temperatures in the Rhone and Garonne rivers are too high.

In Iraq, supply to most of the country went down on Monday as millions of Shiite pilgrims descended on the city of Karbala for the Arba’in festival, spiking grid demand for fans and air conditioners as the mercury rose above 40 degrees Celsius.

Even back-up equipment struggles in such conditions: With the heat rising into the 30s degrees Celsius, electricity went out and play was suspended at the Cincinnati Open tennis tournament this week, after an on-site generator apparently overheated.

Power that goes out when we most need it should infuriate and frustrate but not surprise us. Most of our infrastructure is designed to perform within specific temperature ranges that the global climate is rapidly leaving behind. More and more of it is likely to start breaking as heatwaves become more intense and widespread.

HARDER TO DUMP EXCESS HEAT

That’s particularly the case with thermal generators – those that use the heat from burning fuels or atomic decay to spin turbines and induce electrical charges. Such plants have to find a way to dump excess heat, but this gets harder as the air and water outside warm up.

The result is decreasing efficiency and overheating, forcing the plants to burn more fuel for the same output, or even halt operations altogether. 

Those effects can be significant. The probability that a coal generator will have a forced outage goes up by 3.2 percentage points during heatwaves, while gas and nuclear are respectively 1.3 and 1 percentage points more likely to suffer an unplanned failure, according to a recent study by researchers in Sweden and Italy. Separately, Iraqi researchers found that a gas plant lost about 21 per cent of its generation potential as the temperature rose from 25 degrees Celsius to 50 degrees Celsius.

Drought, which commonly occurs alongside heatwaves, makes the problem worse. Most thermal generators cool themselves by heating up water, whether it’s in the sea, rivers or cooling towers. Cool water, like cool air, gets less abundant as the temperature rises.

India has lost 19 days’ worth of coal electricity since 2014 because water shortages have forced shutdowns, Reuters reported recently. In many areas, residents depend on tanker trucks and ever-deeper boreholes because generators are using up all of the surface water. Power stations may put more pressure on supplies of H2O between now and 2050 than the drinking water needs of its population, according to government forecasts. 

Conventional generators aren’t the only ones to suffer. As anyone who’s sat through a still, sticky summer day would recognise, wind speeds often plummet in hot weather.

Since the early 1980s, the area of the globe affected by such conditions has increased by 6.3 per cent every decade, to the point that about 60 per cent of the planet is now at risk. In Australia, Siberia, and Europe, the availability of wind can now decline by 30 per cent to 50 per cent during heatwaves relative to what it would be in normal years – though a few areas, such as the northern United States, east Africa, the Amazon, and western China, experience the opposite effect.

DEMAND RISES WITH THE MERCURY

Even if we can solve the problem of generating energy, getting it to consumers presents challenges.

Transmission cables and transformers heat up as electrons travel through their wires, and rising air temperatures make such components more susceptible to failure – especially as they’re typically working harder on such days due to all the air conditioners and fans running.

It’s not just people who need relief from the heat. About a third of electricity consumption from data centres comes from heating and cooling to maintain stable temperatures on-site.

That demand rises along with the mercury, and is becoming more pressing with the spread of artificial intelligence and cryptocurrencies. A heatwave in 2022 caused chaos at two London hospitals when their server racks shut down, scrambling the IT systems they depend on to process medical data.

The rising dominance of solar panels and lithium-ion batteries, which tend to be more resilient than thermal generators and wind during heatwaves, will offer some respite. It still may not be enough.

Most of our industrial civilisation, built from the energy riches unleashed by coal, oil and gas, depends on a moderate climate that their carbon emissions are throwing into disorder. The damage caused by fossil technology is going to be with us long after we’ve switched to cleaner ways of generating power.