Elon Musk’s Answer To Stephen Colbert’s Vision Of Wireless Charging(techcrunch.com)
techcrunch.com
Elon Musk’s Answer To Stephen Colbert’s Vision Of Wireless Charging
http://techcrunch.com/2014/07/25/elon-musks-answer-to-stephen-colberts-vision-of-ambient-wireless-charging-well-do-it/
30 comments
[deleted](3)
I really wish people who talk about wireless charging would do some math.
To get any efficiency, you need to tightly constrain the EM field, at which point, you are effectively hitting a plug anyway.
Or, you are accepting enormous radiative losses and losing massive amounts of power. Doubling or tripling the power draw in every device just so it's powered wirelessly is a non-starter.
For cars, we're more likely to get automated charging stations that just plug themselves in. That's going to be a useful problem to solve.
To get any efficiency, you need to tightly constrain the EM field, at which point, you are effectively hitting a plug anyway.
Or, you are accepting enormous radiative losses and losing massive amounts of power. Doubling or tripling the power draw in every device just so it's powered wirelessly is a non-starter.
For cars, we're more likely to get automated charging stations that just plug themselves in. That's going to be a useful problem to solve.
When people actually do the math they get promising results. WiTricity claims over 95% efficiency "when the devices are relatively close to one another". I think to charge a car from a parking space over 90% efficiency is possible.
http://www.ted.com/talks/eric_giler_demos_wireless_electrici...
http://en.wikipedia.org/wiki/Resonant_inductive_coupling
Out of curiosity, how much does it typically cost to charge, say, an iPhone5? For some (many?) doubling this price might not be as much of a non-starter as you think.
At 100% efficiency, much less than a cent. http://www.wolframalpha.com/input/?i=5.45+Wh+*+%280.26+EUR%2...
No clue how efficient typical USB charging is, the AC-DC conversion is at around 80%, then you've got the battery chemistry which cursory research seems to peg at around 80% efficiency as well. So lets say it's about 1c per charge, at EU power prices.
No clue how efficient typical USB charging is, the AC-DC conversion is at around 80%, then you've got the battery chemistry which cursory research seems to peg at around 80% efficiency as well. So lets say it's about 1c per charge, at EU power prices.
Doubling is an underestimate. It's more like a factor of 10.
Still, multiplying the cost of charging an iPhone by 10 isn't bad. And in fact you can buy a lot of solutions that enable this, because you're right, it's not a big deal for a lot of people, and the convenience is worth the cost.
For an electric car, increasing the charging cost by a factor of 10, or even a factor of 2, is a much tougher proposition.
Still, multiplying the cost of charging an iPhone by 10 isn't bad. And in fact you can buy a lot of solutions that enable this, because you're right, it's not a big deal for a lot of people, and the convenience is worth the cost.
For an electric car, increasing the charging cost by a factor of 10, or even a factor of 2, is a much tougher proposition.
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Furthermore, Any reduction in the efficiency of electrical systems for (slight) convenience gains seems like a Bad Idea right now. If we were awash in clean energy (and weren't worried about thermal pollution) then ... maybe.
>For cars, we're more likely to get automated charging stations that just plug themselves in. That's going to be a useful problem to solve.
Maybe I just happen to have a good idea, but that seems easy to do.
Maybe I just happen to have a good idea, but that seems easy to do.
Canadians can watch here: http://www.thecomedynetwork.ca/Shows/TheColbertReport?vid=40...
And people outside of North America can view it here: http://www.youtube.com/watch?v=dUDCIfI-wRs
The thing about Elon Musk is if he says he'll do it, he WILL do it.
There is already a startup in Boston doing this http://www.witricity.com/
Nokia has already done what this company is doing in their Windows Phones. What Colbert was talking about is something much different.
I don't like techcrunch, I expect very little to no journalism from them. But that was one of the worst written, contentless, fluff writing bordering on vapid that I have had poor fortune to read.