Philippa Kaur

Charging an electric vehicle at night can reduce the demand on the power gridifeelstock/Alamy
A small financial reward can persuade many electric vehicle owners to charge their electric cars during off-peak nighttime hours – even when behavioural nudges fail to have the same effect.
That is the finding of a real-world trial that demonstrated how modest monetary incentives can ease the demand on power grids during peak usage hours. Such flexibility could be crucial as the number of people driving electric vehicles continues to grow worldwide.
Advertisement
“Offering an incentive to shift charging to the off-peak hours clearly reduced peak hours charging by 50 per cent, with a commensurate increase in off-peak hours charging,” says Blake Shaffer at the University of Calgary in Canada.
He and his colleagues enlisted 200 electric vehicle owners in Calgary and randomly split them into three groups. One received a financial incentive equivalent to 3.5 cents per kilowatt-hour of electricity use – roughly equivalent to $10 per month – if they charged their cars at home between 10 pm and 6 am, a period when electricity demand on the grid is usually lower. A second group only received a behavioural nudge consisting of information on the societal benefits of charging their electric cars during off-peak hours. A third group acted as a control, merely monitored to track baseline charging habits.
Surprisingly, the behavioural nudge strategy proved “completely ineffective”, says Shaffer. “Just asking them to do it out of the goodness of their heart didn’t show a strong enough effect.” But he suggests that more frequent reminders beyond the initial notice might have been more successful.
By comparison, the financial reward significantly shifted charging times – but only as long as people kept receiving money. Any reward cutoff led them to immediately revert to their old charging habits.
“The analysis does a convincing job of showing how a small financial incentive can really affect electric vehicle charging behaviour,” says Kenneth Gillingham at Yale University. Such incentives may have seemed like “easy money” because charging vehicles at night wasn’t too inconvenient, he says.
This is important because “many grids would need substantial upgrades” if growing numbers of electric vehicles are charging earlier in the evening, during peak demand hours, says Andrea La Nauze at Deakin University in Australia. Her own research has shown how financial incentives can encourage Australian electric car owners to charge during the day, when solar power is delivering maximum electricity to the grid.
Meanwhile, some utility companies – such as Con Edison and Orange & Rockland in New York – have already begun offering similar incentive programmes for off-peak charging.

Topics:behaviour/electric vehicles More

Hominins have been using fire for various reasons for at least 1 million yearsSHEILA TERRY/SCIENCE PHOTO LIBRARY
Mastering fire may have also led to genetic changes that helped early humans survive mild burn injuries, but this evolutionary trait could complicate the treatment of more severe cases today.
An early-stage study suggests that the selection of genes preventing deadly infections that could arise from minor burns were prioritised in early Homo sapiens, but these same genes interfere with the healing of severe ones. This may be because, in primitive times, people with severe burns had almost no hope of surviving.… More

Reindeer fur would have helped ancient humans endure the climate of the last glacial maximumEsteban De Armas/Shutterstock
An open-air site in Austria occupied by humans during the coldest part of the last glacial period may have been dedicated to hunting reindeer for pelts, showing how people adapted to extreme temperatures in Europe.
The site, called Kammern-Grubgraben, was heavily occupied from around 24,000 to 20,000 years ago and contains the largest abundance of tools, ornaments, artefacts and stone structures in Europe during the cold and unforgiving most recent glacial maximum. At this time, the mean annual temperature… More

We know from ancient texts that Roman gladiators fought lions, but physical evidence has been lacking until nowDEA PICTURE LIBRARY/De Agostini via Getty Images
Bite marks on the pelvis of a man who lived in Roman-occupied Britain were probably made by a lion in gladiatorial combat.
The findings provide the first physical evidence that people battled animals in gladiator arenas in Europe, says Tim Thompson at Maynooth University in Ireland.

Gladiator spectacles involving wild cats, bears, elephants, and other animals are frequently described in Roman art and texts. But despite those accounts and the hundreds of excavated Roman amphitheatres scattered across the ancient empire, none of the approximately 200 suspected gladiator skeletons uncovered so far have shown clear signs of an animal attack.
During an urban development project in 2004 and 2005, scientists excavated the remains of about a hundred people from the Roman era just outside York, UK – a city originally founded by the Romans as Eboracum. Most of the people buried there from the 1st to the 4th centuries AD were young men, riddled with traumatic injuries and often decapitated.
One of the skeletons bore unusual depressions and puncture marks across both hips, which researchers thought might be evidence of a carnivore attack.
To find out, Thompson and his colleagues ran 3D scans on the ancient pelvis and compared their findings with scans of fresh bite patterns on the bones of animal carcasses – mostly horses – that had been fed to lions, leopards, cheetahs and tigers in zoos.
The researchers found that the 10 bite marks on the bones of the suspected gladiator closely matched those made on horse bones by zoo lions. Similarities included the position of the teeth marks, as well as the depth of their marks into the bone after piercing through soft tissue.
Part of the pelvis of a Roman-era man, with a bite mark made by a big catPLOS One
“We’re talking about some quite big teeth going through all these layers of the body,” says Thompson.
Even so, the bite was unlikely to be fatal: “It would sting,” he says. But when going for the kill, lions usually attack the throat.
“What probably happened here is that the individual got knocked down by some other means, and then the lion dragged him away.”

Historic Herculaneum – Uncovering Vesuvius, Pompeii and ancient Naples

Embark on a captivating journey where history and archaeology come to life through Mount Vesuvius and the ruins of Pompeii and Herculaneum.

Find out more

Topics:archaeology More

The now-extinct Tocharian language on a scrap of parchmentSakkmesterke/Alamy
ProtoLaura Spinney (HarperCollins (UK) Bloomsbury Publishing (US, 13 May))
A new book by Laura Spinney is rather tantalisingly called Proto, begging the question: proto-what? Prototype, the earliest version of a technology? Protoplasm, the stuff of our cells? Or even protoplanet, a small hunk of space rock with a big future ahead?
The answer, in fact, sits above and across those words: Proto-Indo-European. This is the great original language from which English, among many other tongues, both alive and dead, derives. As Spinney puts it: “Almost every second person on… More