A recent review car accidentally showed me that my iPhone 8 has wireless charging capability, when I put it on the charging shelf simply for convenience, writes Brian Byrne. A green 'charging' indicator on the Apple Carplay screen caught me by surprise. That was understandable.
For a number of years now my phones have been passed on by eldest son, who tends to use the latest tech, changing every few years or so. I appreciate this not just because I get a fairly up to date model, but also because it makes good environmental sense that, for the cost of a new battery, the otherwise perfect phone is still being used. So, I wouldn't have known about its wireless charging capability as I wasn't looking at specs for the purpose of buying a phone.
Anyhow, I let the phone charge while I was driving, and when I stopped later, I found it had got quite warm. Heat and electronic devices are normal bedfellows, but the amount needs to be limited so I did a little online research. Also, I have enough scientific knowledge to know that heat is a sign of inefficient energy transfer, however that is. It's why your petrol engine generates enough heat to warm the car's interior in even freezing outside conditions.
My searches showed that I shouldn't be worried about the heat from a damage point of view, according to Apple et al. But my other interest, efficiency, was a different matter. According to some of those who checked out such things, wireless charging takes significantly more electricity to fully charge a device than if it is simply plugged in the old money way. In one independent test, a typical phone needed 47pc more electricity to get a full charge compared to from a wired setup. There were also issues with correct alignment of the phone and the charge mat, which could result in even more inefficiency.
Now, the amount of electricity used to charge a phone is quite small, but if there was a significant shift to wireless charging, at scale it would make a big environmental impact. In that article I'm quoting, the writer got a suggestion that for the 3.5 billion phones in use, it could mean double the estimated 73 power stations it takes to power them at the moment. Not likely to happen, of course, but it does give context.
Why is this important? Well, as we move ever further down the road of electric cars, and vans — there's even an electric full-size truck on the way from Mercedes-Benz — there is research into in-road dynamic charging. Essentially, wireless charging of big batteries in vehicles by having them parked over the system. Or while being driven along stretches of road in which there are charging systems embedded.
The same laws of energy dynamics will apply there too. On a much larger scale than with a mobile phone. A scale that will need a much more robust electricity grid infrastructure than we have at the moment. And, importantly, one that's totally dependent on sustainable non-fossil power generation.
We're not there yet. Not for a long yet. But it's worth thinking about. Especially the inbuilt inefficiency. Meantime, I stick to that old fashioned cable to keep my phone juiced.
