[adevine]

My understanding, though, is that all of these wireless charging solutions are significantly less efficient that wired power. Even if it's, say, 10% less efficient, that's a huge, huge waste of energy on a large scale if this technology becomes popular.

[comex]

Waste is relative. A smartphone uses around 1% the electricity per year of a refrigerator; I don't know if upping that even to, say, 10% would make all that much difference in the grand scheme of things.

[mikeyouse]

Because I'm slow at work..

If we say the new generation iPhones have a 3,000mah battery, batteries are charged fully once per day, and that 100 million people in the US have iPhones:

3,000mah x 3.8v = 11.4 watt-hours to fully charge a phone -- at $0.15/kWh, this equates to a daily expense of ~$0.002 to charge your phone. Annually, this is $0.62. If wireless charging were 50% efficient, it would still cost under a dollar annually to charge your phone.

On a bigger scale:

11.4Wh * 365 days * 100M phones = 416 billion watt-hours annually to charge all the iPhones in the US. A 50% efficiency loss would equate to a difference of 208 billion Wh.

Enercon makes a monster wind turbine called the E-126 that has a 7.6mW generator attached. With a modest 40% capacity factor, you would only need 8 additional wind turbines to make up for every iPhone user in the US switching to wireless charging.

[simcop2387]

Actually a 50% efficiency loss would double the energy requirements to 800+ billion watt hours. Your original calculation is right for 100% efficiency in charging over wires.

[mikeyouse]

Ah! Good point. I can't edit but double the turbines.

[antocv]

How much to make up for all the cancers people would get with increased radiation all around them?

[adevine]

Non-ionizing radiation does not cause cancer

[raverbashing]

10% less efficient?

I think charging my phone loses about 5% in thermal losses at the connector (because it gets warm)

10% is both not important (in this context) and unfortunately optimistic

[MrQuincle]

And this does not even consider the counterfeit adapters many people use. I think wireless might be more efficient than many badly designed adapters.

[agumonkey]

Depends, how much energy is used in making cables that break, get lost ? Even though building the wireless adapter endpoints will also be costly ... hmm

[samstave]

Also, count how many failed/shitty cables you have had in your history- I've had literally hundreds of cables for charging only purposes. Fuck all that plastic and material waste when the cable only lasts N months...

Further, it pisses me off that every device has a diff charging interface. Fine, go ahead and have a diff data delivery cable for high speed file trans but fuck you to every manufacturer where the charging interface is unique...

I'm looking at you every laptop manufacturer ever...

[eridius]

Induction charging is definitely less effective, and loses a lot of energy to waste heat. This is why, when you take an Apple Watch off of its charger, the back is very warm.

[mtgx]

I think it's more than 10%. At least 20%. Maybe even 50%.

[ProAm]

Not only is it inefficient but I believe the heat produced while charging seriously degrades the battery and reduces it's expected lifespan.

[loteck]

Why do you believe this?

[ProAm]

Its just from stuff Ive read when researching at a Qi charger to my phone. Temperature definitely affects battery lifetime.

[duaneb]

Why would it not be absorbed by proportional savings in heating?

[hyperpape]

Depends where you live. We spend more of the year running AC here.

[duaneb]

Very good point.

[g52oevr0in]

This is true only if your home is running an electric heater. Burning hydrocarbons like natural gas, oil, and wood to heat your home directly is more efficient than using them to run a turbine to generate electricity, then run that electricity many miles to your home, then turn it into heat.

[samstave]

Teleporting heat. Got it.

[kiiski]

District heating[1] has been around for a long time. At least here in Finland most people in cities use it.

[1]: https://en.wikipedia.org/wiki/District_heat