Month: April 2019

Enlarge (credit: Valentina Palladino)

Update: Ars has stayed busy after publishing this guide in April 2019. We've tested a number of new Qi wireless chargers available since and have updated our top picks ahead of the 2019 holiday shopping season.

Wireless charging has a long way to go before it replaces wired charging, but the technology has advanced dramatically in the past few years. Everyone with the newest smartphones, wearables, and other gadgets can get behind the idea—simply place your device on a charging pad or stand and let it sit. Within a few minutes, you'll have more battery power than you did before, and you didn't have to fuss with wires or cables to get it.

But quite a bit of technology goes into making an accessory that makes your life that much easier. Most wireless chargers come in the form of circular or rectangular pads, some of which are propped up on legs to make stands that take up minimal space and work well as nightstand or desk accessories. But don't be fooled by their minimalist exteriors—there are a number of things you should know before investing in a wireless charging pad. To navigate this murky world, Ars tested out some of the most popular Qi wireless chargers available now to see which are worth buying.

Enlarge / DUNKIRK, NEW YORK, 2016: A NRG-owned coal fired energy facility that planned to convert to a natural gas facility. (credit: John Greim/LightRocket via Getty Images)

Coal is among the most polluting fuels that nations around the world use regularly to create electricity. It's especially bad in terms of carbon dioxide (CO₂) emissions, and in order to slow climate change, we'll need to retire coal plants sooner rather than later.

Many have argued that, rather than retiring coal plants completely, they should be altered to burn natural gas if possible. Natural gas emits less than half the amount of carbon dioxide that coal does when it's burned, and it also emits fewer nitrogen oxides and less sulfur dioxide, pollutants that are harmful to human health. Natural gas is also dispatchable; unlike with renewables, we don't have to wait for the sun or the wind to appear to start generating electricity.

But using natural gas comes with less-obvious costs. Natural gas itself is mostly methane (CH₄), which is an extremely potent greenhouse gas before it's combusted, although its lifetime in the atmosphere is much shorter than CO₂. Numerous recent reports show that natural gas operations leak an uncertain amount of that methane—making it difficult to determine whether replacing coal with natural gas is actually better, at least in the short term, when lifecycle analyses of both fuels are compared.