Electric car boom drives surge in charging-station demand

On a road trip to California from Toronto in his Tesla Model S, Daniel Valadares got a taste of just how popular the luxury electric cars are on the West Coast. The whole way there — the tech consultant did the trip in 68 hours, swapping driving duties with three companions, including his mother — they didn't once have any hitches charging up the car's battery at any of the dozens of Tesla power stations along the way.

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But at the Tesla supercharger station in San Mateo, just south of San Francisco, all eight charging spots were taken when he arrived, so he had to wait. A popular charging station by a scenic ranch a few hours southeast often has waits of 30 or 40 minutes to get a quick refill, he said.The major consumer concern with early models of electric cars revolved around something called "range anxiety," the fear that the battery would run out before you could make it to your destination or a charging station. But now that charging stations abound — there are thousands publicly available across Canada for all makes of electric cars — an emerging worry is that electric cars are becoming so popular, there will be too much charging station congestion to plug in when you need to, particularly once Tesla's mass-market Model 3 arrives."I'm on the blogs and forums, and people are afraid of having that happen. I think this is going to be a problem in the future," Valadares said.

At Plugshare.com, a website that maps North American charging stations, people complain of just that.

"I'm waiting my turn for a quick charge," a commenter posted last April while in line at Montreal's only public quick-charging station.

"We're three people here at the same time! A recharge that should take 15 minutes will take 45 because we're waiting in line."He said peak times seem to be Friday and Sunday nights on the expressways between Montreal and Quebec City, when travellers are heading out on or coming back from a weekend trip.

"Our data have shown us what sites have had congestion and where we need to build more stations. We want to ensure there's no waiting line and will act in advance to prevent that."

Electric Circuit counted 619 charging stations as of last week, 30 of which are high-voltage quick-charging installations. The province is aiming for a total of 800, including 60 quick-charge, by year's end to meet the needs of its 8,500 electric and plug-in hybrid vehicles.

Ontario is doling out $20 million in grants to get private and public-sector partners to build more charging stations, with the aim of having quick-charging stations every 60 to 80 kilometres along major highways and potentially hundreds of regular-charge terminals in cities. Details are expected to be announced within days.

Robots infiltrate insect world to learn their ways

Others are looking at how robots can infiltrate colonies and influence behaviour. Bee bots could protect pollinating bees against mites – or keep a hive updated with weather forecasts, releasing pheromones to prevent a new brood hatching when bad weather is likely to prevent foraging. Robots can even be used to encourage groups of animals to do things they normally would not: a robo-roach can trick cockroaches into venturing into the light, for example. But getting the robots to behave in a way that makes them blend in can be tricky. In previous work, José Halloy at Paris Diderot University in France and his colleagues programmed their robot cockroaches largely by hand. But this is hard – and cannot easily be adapted for use with other types of animal. So Halloy’s team has now developed a way to generate the robots’ behaviour automatically using a mix of descriptions of cockroach habits, combining models of individuals’ movement with group activity. They then usedevolutionary algorithms to optimise the models.Programming the robots to behave like individual insects is not the best way, says team member Nicolas Bredeche at Paris-Sorbonne University. “You don’t know if these small details will capture the global behaviour of the cockroaches when they are together,” he says.

The team tested their generated behaviours in a computer simulation in which a mixed group of 45 cockroaches and five robots had to cooperate to make a collective choice between two shelters. Generating insect-mimicking behaviour automatically was a lot quicker than doing it by hand – and led to more lifelike behaviour. They found that the mixed group acted like a real cockroach group – grouping along walls in realistic ways, for example.

The team think that the approach could be used to generate behaviours for mimics of other social species, such as honeybees, fruit flies, birds and fish. Behaviour is much more important than looks, says Bredeche. A fish will accept a robot as another fish if it acts like one, even if it doesn’t look the part. And group level behaviour matters even more than individual actions. The movement and paths followed by the robo-roaches did not need to match those of real cockroaches for them to fit in.

Using robots that mimic and influence behaviour as well as traditional techniques such as sounds and pheromones is a great addition to researchers‘ toolkit, says Terry Page at Vanderbilt University in Nashville, Tennessee.

Small, cheap gravity gadget to peer underground

Such gravimeters already exist but compared to this postage stamp-sized gadget, they are bulky and pricy. The new design is based on the little accelerometers found in smartphones. To begin with, the team - from the University of Glasgow - tested it by measuring the Earth's tides over a period of several days. Tidal forces, caused by the interacting pull of the Sun and Moon, not only drag the oceans up and down but slightly squash the Earth's diameter. "It's not a very big squeeze, but it means that essentially Glasgow - or anywhere else on the Earth's crust - goes up and down by about 40cm over the course of 12-13 hours," said Richard Middlemiss, the PhD student who made the new instrument. "That means that we get a change in gravitational acceleration - so that's what we've been able to measure."In fact, Mr Middlemiss and his colleagues, writing in the journal Nature, report that their contraption can detect even smaller gravity changes - such as those that would be caused by a tunnel less than 1m across, buried 2m underground.

Fleets of these devices could eventually be scattered around volcanoes or mounted on drones, they suggest, to conduct subterranean surveys.

They could even help civil engineers locate pipes under roads, Mr Middlemiss said, to save them digging in the wrong places. "What we wanted was to make a gravimeter that was very small and very cheap." Speaking to BBC News, he estimated that the device - in a few years' time - could be priced in the hundreds of pounds. This is much better than the £70,000-plus charged for today's commercial gravimeters, which are largely the preserve of wealthy oil companies.

The UK team has a patent pending on its design.It was working with fellow Glasgow physicists and engineers - including some of those involved in the recent detection of gravitational waves - that made the development possible, he added. But those famous ripples in space-time are well beyond Mr Middlemiss's small, silicon sensor.

"There is absolutely no way that our device could measure gravitational waves! But it's the expertise that's come out of the Institute of Gravitational Research, and the gravitational wave community generally, that has allowed us to do this."

For example, those colleagues showed him the importance of controlling the temperature in his sensor - while those in the School of Engineering helped him work out how to fabricate it.