Wireless charging is increasingly common in modern smartphones, and there’s even speculation that Apple might ditch charging via a cable entirely in the near future. But the slight convenience of juicing up your phone by plopping it onto a pad rather than plugging it in comes with a surprisingly robust environmental cost. According to new calculations from OneZero and iFixit, wireless charging is drastically less efficient than charging with a cord, so much so that the widespread adoption of this technology could necessitate the construction of dozens of new power plants around the world. (Unless manufacturers find other ways to make up for the energy drain, of course.)

无线充电是在现代智能手机越来越普遍，甚至还有传言称苹果可能会抛弃通过电缆完全充电在不久的将来。 但是，通过将手机放在垫子上而不是插入手机来榨汁会带来一些小小的便利，这会带来令人惊讶的强劲环境成本。 根据OneZero和iFixit的最新计算，无线充电的效率大大低于使用线充电的效率，因此无线充电的效率如此之高，以至于该技术的广泛采用可能需要在全球范围内建造数十座新的发电厂。 (当然，除非制造商找到其他方法来弥补能量消耗)。

On paper, wireless charging sounds appealing. Just drop a phone down on a charger and it will start charging. There’s no wear and tear on charging ports, and chargers can even be built into furniture. Not all of the energy that comes out of a wall outlet, however, ends up in a phone’s battery. Some of it gets lost in the process as heat.

在纸上，无线充电听起来很吸引人。 只需将手机放到充电器上，它将开始充电。 充电端口没有磨损，甚至可以将充电器内置在家具中 。 但是，并非所有从壁装电源插座中散发出来的能量最终都被手机的电池所消耗。 在此过程中，有些热量会因热量而流失。

While this is true of all forms of charging to a certain extent, wireless chargers lose a lot of energy compared to cables. They get even less efficient when the coils in the phone aren’t aligned properly with the coils in the charging pad, a surprisingly common problem.

尽管在某种程度上所有形式的充电都是如此，但与电缆相比，无线充电器会损失很多能量。 当电话中的线圈与充电板中的线圈未正确对准时，它们的效率甚至更低，这是一个令人惊讶的普遍问题。

To get a sense of how much extra power is lost when using wireless charging versus wired charging in the real world, I tested a Pixel 4 using multiple wireless chargers, as well as the standard charging cable that comes with the phone. I used a high-precision power meter that sits between the charging block and the power outlet to measure power consumption.

为了了解现实中使用无线充电与有线充电时会损失多少额外电量，我测试了使用多个无线充电器以及手机随附的标准充电电缆的Pixel 4。 我使用了位于充电块和电源插座之间的高精度功率计来测量功耗。

In my tests, I found that wireless charging used, on average, around 47% more power than a cable.

在测试中，我发现无线充电平均比电缆多使用47％的电量。

Charging the phone from completely dead to 100% using a cable took an average of 14.26 watt-hours (Wh). Using a wireless charger took, on average, 21.01 Wh. That comes out to slightly more than 47% more energy for the convenience of not plugging in a cable. In other words, the phone had to work harder, generate more heat, and suck up more energy when wirelessly charging to fill the same size battery.

使用电缆将电话从完全没电到100％充电，平均需要14.26瓦特小时(Wh)。 使用无线充电器平均需要21.01 Wh。 为了不插入电缆，这将多消耗47％的能量。 换句话说，当无线充电以填充相同大小的电池时，电话必须更加努力地工作，产生更多的热量并吸收更多的能量。

How the phone was positioned on the charger significantly affected charging efficiency. The flat Yootech charger I tested was difficult to line up properly. Initially I intended to measure power consumption with the coils aligned as well as possible, then intentionally misalign them to detect the difference.

手机在充电器上的放置方式会严重影响充电效率。 我测试过的扁平Yootech充电器很难正确排列。 最初，我打算在线圈尽可能对齐的情况下测量功耗，然后有意地将它们对齐以检测差异。

Instead, during one test, I noticed that the phone wasn’t charging. It looked like it was aligned properly, but while trying to fiddle with it, the difference between positions that charged properly and those that didn’t charge at all could be measured in millimeters. Without a visual indicator, it would be impossible to tell. Without careful alignment, this could make the phone take way more energy to charge than necessary or, more annoyingly, not charge at all.

相反，在一次测试中，我注意到电话没有充电。 看起来好像对齐正确，但是在尝试摆弄时，可以正确测量充电正确的位置与根本不充电的位置之间的差，单位为毫米。 没有视觉指示器，就无法分辨。 如果不仔细对齐，这可能会使手机充电所需的能量过多，或者更烦人的是根本无法充电。

The first test with the Yootech pad — before I figured out how to align the coils properly — took a whopping 25.62 Wh to charge, or 80% more energy than an average cable charge. Hearing about the hypothetical inefficiencies online was one thing, but here I could see how I’d nearly doubled the amount of power it took to charge my phone by setting it down slightly wrong instead of just plugging in a cable.

在我想出如何正确对齐线圈之前，使用Yootech垫进行的首次测试需要25.62 Wh的充电功率，比普通电缆充电要多80％的电能。 听到在线上假定的低效率是一回事，但是在这里我可以看到，通过稍微错误地将其设置为手机而不是仅仅插入电缆，我将手机充电所需的电量几乎增加了一倍。

Google’s official Pixel Stand fared better, likely due to its propped-up design. Since the base of the phone sits flat, the coils can only be misaligned from left to right — circular pads like the Yootech allow for misalignment in any direction. Again, the threshold was a few millimeters of difference tops (as seen below), but the Pixel Stand continued charging while misaligned, albeit slower and using more power. In general, the propped-up design helped align the coils without much fiddling, but it still used an average of 19.8 Wh, or 39% more power, to charge the phone than cables.

Google的官方Pixel Stand表现更好，这可能是由于其支持的设计。 由于手机的底座是平坦的，因此线圈只能从左到右错位-类似于Yootech的圆形垫可以在任何方向上错位。 同样，阈值是差值顶部的几毫米(如下所示)，但Pixel Stand仍在未对准的情况下继续充电，尽管速度较慢且使用了更多功率。 通常，支撑式设计有助于对齐线圈，而不会产生任何干扰，但与电话线相比，它仍然平均使用19.8 Wh或39％的功率为手机充电。

On top of this, both wireless chargers independently consumed a small amount of power when no phone was charging at all — around 0.25 watts, which might not sound like much, but over 24 hours it would consume around six watt-hours. A household with multiple wireless chargers left plugged in — say, a charger by the bed, one in the living room, and another in the office — could waste the same amount of power in a day as it would take to fully charge a phone. By contrast, in my testing the normal cable charger did not draw any measurable amount of power.

最重要的是，两个无线充电器在完全没有电话充电时会独立消耗少量电量-大约0.25瓦，听起来可能不多，但是在24小时内，它将消耗大约6瓦时。 一个拥有多个无线充电器的家庭(例如，床旁的充电器，一个客厅的充电器和办公室的另一个充电器)可能一天要消耗与为手机充满电相同的电量。 相比之下，在我的测试中，普通的电缆充电器没有消耗任何可测量的电量。

While wireless charging might use relatively more power than a cable, it’s often written off as negligible. The extra power consumed by charging one phone with wireless charging versus a cable is the equivalent of leaving one extra LED light bulb on for a few hours. It might not even register on your power bill. At scale, however, it can turn into an environmental problem.

尽管无线充电可能比电缆消耗更多的电能，但通常忽略不计。 用无线充电方式给一部手机充电而不是用电缆充电，所消耗的额外功率相当于将一个额外的LED灯泡打开几个小时。 它甚至可能没有在您的电费单上注册。 但是，从规模上讲，这可能会成为环境问题。

“I think in terms of power consumption, for me worrying about how much I’m paying for electricity, I don’t think it’s a factor,” Kyle Wiens, CEO of iFixit, told OneZero. “If all of a sudden, the 3 billion[-plus] smartphones that are in use, if all of them take 50% more power to charge, that adds up to a big amount. So it’s a society-wide issue, not a personal issue.”

iFixit首席执行官Kyle Wiens告诉OneZero： “我认为在功耗方面，我担心自己要付多少电，我认为这不是一个因素。” “如果突然之间，正在使用的30亿( + )部智能手机，如果所有人都需要多充电50％的电量，那将是一个很大的数目。 因此，这是一个全社会的问题，而不是个人问题。”

To get a frame of reference for scale, iFixit helped me calculate the impact that the kind of excess power drain I experienced could have if every smartphone user on the planet switched to wireless charging — not a likely scenario any time soon, but neither was 3.5 billion people carrying around smartphones, say, 30 years ago.

为了获得规模参考，iFixit帮助我计算了如果地球上的每个智能手机用户都切换到无线充电的情况，我所经历的过剩功率消耗可能会产生的影响-短期内不太可能出现这种情况，但3.5都不是30年前，有数十亿人随身携带智能手机。

“We worked out that at 100% efficiency from wall socket to battery, it would take about 73 coal power plants running for a day to charge the 3.5 billion smartphone batteries once fully,” iFixit technical writer Arthur Shi told OneZero. But if people place their phones wrong and reduce the efficiency of their charging, the number grows: “If the wireless charging efficiency was only 50%, you would need to double the [73] power plants in order to charge all the batteries.”

“我们计算出，从墙上插座到电池的100％效率，这将需要约73家燃煤电厂 iFixit技术撰稿人Arthur Shi告诉OneZero ，该设备可以运行一天，为35亿只智能手机电池一次充满电。 但是，如果人们放错手机并降低充电效率，数字就会增加：“如果无线充电效率仅为50％，则您需要将[73]家发电厂加倍才能为所有电池充电。”

If everyone in the world switched to wireless charging, it would have a measurable impact on the global power grid.

如果世界上每个人都转向无线充电，那将对全球电网产生可观的影响。

This is rough math, of course. Measuring power consumption by the number of power plants devices require is a bit like measuring how many vehicles it takes to transport a couple dozen people. It could take a dozen two-seat convertibles, or one bus. Shi’s math assumed relatively small coal power plants outputting 50 MW, as many power plants in the United States are, but those same needs could also be met by a couple very large power plants outputting more than 2,000 MW (of which the United States has only 29).

当然，这是粗略的数学运算。 用发电厂设备所需的数量来测量功耗有点像测量运送数十人的车辆需要多少辆车。 可能需要一打十二座两厢敞篷车或一辆公共汽车。 史的数学假设与美国的许多发电厂一样，煤电厂的产量相对较小，只有50兆瓦，但同样的需求也可以通过几个发电量超过2,000兆瓦的大型电厂来满足(美国仅29 )。

However, the broader point remains the same: If everyone in the world switched to wireless charging, it would have a measurable impact on the global power grid. While tech companies like Apple and Google tout how environmentally friendly their phones are, power consumption often goes overlooked. “They want to cover the carbon impact of the product over their entire life cycle?” Wiens said. “The entire life cycle includes all the power that these things ever consumed plugged into the wall.”

但是，更广泛的观点保持不变：如果世界上每个人都转向无线充电，那么它将对全球电网产生可观的影响。 尽管像苹果和谷歌这样的科技公司吹捧手机的环保性，但功耗却常常被忽略。 “他们想涵盖产品在整个生命周期中的碳影响吗？” 维恩斯说。 “整个生命周期包括这些东西消耗掉的所有能量插入墙壁中。”

There are some things that companies can do to balance out the excess power wireless chargers use. Manufacturers can design phones to disable wireless charging if their coils aren’t aligned — instead of allowing excessively inefficient charging for the sake of user experience — or design chargers to hold phones so they align properly. They can also continue to offer wired charging, which might mean Apple’s rumored future port-less phone would have to wait.

公司可以采取一些措施来平衡无线充电器使用的过多功率。 制造商可以设计手机以在线圈未对准时禁用无线充电-而不是为了用户体验而允许效率过低的充电-或设计充电器以容纳手机以使其正确对准。 他们还可以继续提供有线充电功能，这可能意味着苹果公司传言未来的无端口手机将不得不等待。

Finally, tech companies can work to offset their excesses in one area with savings in another. Wireless charging is only one small piece of the environmental picture, and environmental reports for major phones from Google and Apple only loosely point to energy efficiency and make no mention of the impact of using wireless chargers. There are many ways tech companies could be more energy-efficient to put less strain on our power grids. Until wireless charging itself gets a more thorough examination, though, the world would probably be better off if we all stuck to good old-fashioned plugs.

最后，科技公司可以努力在一个领域中节省过多的费用，而在另一领域中节省费用。 无线充电只是环境图片中的一小部分， 来自Google和Apple的主要手机的环境报告仅宽松地指出了能效，没有提及使用无线充电器的影响。 科技公司可以通过多种方式来提高能源效率，以减轻对我们电网的压力。 但是，在无线充电本身接受更彻底的检查之前，如果我们都坚持使用老式的插头，那世界可能会变得更好。

Update: A previous version of this article misstated two units of measurement in reference to the Pixel Stand charger. It consumes 0.25 watts when plugged in without a phone attached, which over 24 hours would consume around six watt-hours.

更新：本文 的先前版本相对于Pixel Stand充电器遗漏了两个测量单位。 在未连接电话的情况下插入时功耗为0.25瓦，而在24小时内将消耗约6瓦时。