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Not having to find the right cable or carry one around with you makes wireless charging a convenient way of charging your mobile devices—iPhone, Apple Watch, AirPods and many third-party gadgets.
There are multiple wireless charging standards and technologies. Here we will explain the major ones—Qi, MagSafe, Qi2 and the latest Qi2 25W (aka Qi2.2). Knowing which is which will help you to make your charging life more efficient. Here we look at Qi2 vs MagSafe and Qi2 25W vs Qi2 and Apple’s updated 2024 version of MagSafe. Which is best for your model of iPhone?
It’s a little more nuanced, but in general, iPhones 16, 17 and 18 (and the iPhone Duo) should now charge wirelessly at up to 25W with supporting certified Qi 2.2 chargers. Older iPhones are limited to the 15W maximum if they support certified Apple MagSafe or Qi2. Chargers that are merely “MagSafe Compatible” are usually limited to 7.5W wireless charging. Note that the iPhone Air is limited to 20W wireless, the 16e to 7.5W and 17e to 15W.
iPhone wireless charging speeds in brief:
Don’t worry too much about the difference between 22W and 25W—the charging time difference will be marginal given environmental conditions such as room temperature will also make an impact.
Wireless charging uses electromagnetic induction to power your devices. The charging pad and your phone both include copper wire coils. Plug the pad into a power source and the charger’s coil generates a magnetic field. When you place your phone onto the charging pad, the phone’s coil converts that magnetic field into an electric current, thus charging the phone.
Apple pioneered improved magnetic connection between charger and phone with MagSafe, and it’s mainly the tighter magnetic fit that drives faster and faster wireless charging.
Qi2—supported by the iPhone 12 and up—speeds up wireless charging from 7.5W to 15W and makes chargers cheaper as well as more efficient. It is very like MagSafe, which is unsurprising as Apple allowed the Wireless Power Consortium (WPC) to use MagSafe as the basis of Qi2.
In short, Qi2 brings the magnetic benefits of MagSafe, but also make third-party iPhone chargers faster and potentially cheaper. Manufacturers are more likely to create new products when the market is larger (iPhone and Android) and costs should come down, too.
Apple’s latest version of its iPhone MagSafe Charger can wirelessly charge the iPhone 16 series at 22-25W. Older iPhones can use this charger but at a 15W maximum as before. Qi2 took its time catching up, but it has now: keep reading.
We have tested Qi2 chargers vs chargers certified as MagSafe by Apple, and can confirm that 15W Qi2 charges supporting devices at an equivalent speed to 15W MagSafe, and much faster than merely MagSafe-compatible 7.5W chargers. More details of our wireless charging speed tests below.
Belkin
The latest Qi2 25W standard (officially Qi 2.2) matches Apple’s 25W wireless charging speed. We have tested many 25W chargers, including the Belkin 25W UltraCharge Pro 3-in-1 Magnetic Charging Dock, Ugreen MagFlow Power Bank, 25W Baseus PicoGo AM52 Power Bank and ESR’s 25W CryoBoost 3-in-1 Charging Station among others.
Samsung waited until its Galaxy S26 Ultra to jump on the fast magnetic wireless charging bandwagon with Qi2 25W, and Google was first out of the Android blocks with Qi2 25W compatibility with its Pixel 10 Pro XL. The lesser Google Pixel 10 Pro is pegged back at 15W Qi2. Google calls its version of Qi2 “PixelSnap”.
First, let’s look at the original Qi, which all iPhones post iPhone 8 support.
Foundry
Qi is a Chinese word that means “energy flow”. Pronounced “chee”, Qi is the basic and most popular wireless charging standard, launched in 2008 but not seen on an iPhone until 2017’s iPhone 8.
Note that plain Qi2 has little magnetic connection between phone and charger so is less efficient at transferring power as more is wasted depending on the placement of the phone on the charger. Better magnetic attachment and therefore faster charging arrived with MagSafe and Qi2.
Apple continues to support the Qi wireless charging standard with its most recent iPhones—and the iPhone 12 and later models are compatible with Qi2, more on which later. This means that iPhones from the iPhone 8 onwards can be placed on a Qi-compatible charger to start charging without a cable. (Of course, the Qi charging pad or stand itself has to be connected via a cable to a power charger.)
While wireless charging means less wear and tear to your devices, it is not as efficient as charging via a cable (wired charging) as some of the energy is lost between the charging pad and the device placed on it.
Qi users will know that you have to ensure your device is placed in exactly the right alignment for fast wireless charging to take place. Place the iPhone on the pad incorrectly and you end up either charging much more slowly or not at all. Many of us have dropped a phone on a Qi charger only to find out later that it wasn’t in the right place and so annoyingly never started charging—a problem largely solved by Apple’s MagSafe.
While Qi’s maximum wireless charge is 15W, Apple’s iPhone supports only 7.5W via Qi.
Qi charging is built into the iPhone 8, X, XR, XS, SE, 11, 12, 13, and 14 families. The iPhone 15/16/17/18 and Air/Duo work with Qi but are rated as Qi2; see later. The outlier is the curious iPhone 16e that goes all the way back to plain old Qi; the 17e is fine.
Foundry
Apple’s magnetic MagSafe iPhones contain a ring of magnets built around its Qi charging coil. As a result, you can magnetically clamp charging accessories onto the iPhone. In fact, you can magnetically attach non-charging accessories, such as wallets and mounts, too.
MagSafe—from 2020’s iPhone 12 on—makes missing the charging pad’s coils much less likely with its ring of magnets quickly finding the charging alignment sweet spot—on a compatible charger—so you will always connect and less energy is wasted.
Magnetic Power Profile (MPP) technology uses magnets to perfectly align the coils of the wireless charging transmitter and receiver before transferring power.
iPhones can work with wireless chargers that are either MagSafe certified by Apple (“made for MagSafe”) or are compatible with MagSafe—plus less sophisticated Qi chargers.
Certified MagSafe chargers can supply up to 25W to the iPhone, while merely MagSafe compatible chargers are limited to 7.5W, but compatible chargers are usually cheaper. That 25W charging speed is currently limited to the iPhone 16 and 17 ranges and Apple’s own MagSafe Charger. iPhones 12/13/14/15 max out at 15W using MagSafe. The iPhone Air won’t charge faster than 20W wirelessly. In fact, the iPhone 16 and 16 Pro are pegged back at 22W, while the larger 16 Plus and 16 Pro Max support the while 25W. The 16e is out of the picture at just 7.5W and the 17e makes it to 15W.
(Note that the iPhone 12 mini only charges at 12W with MagSafe.)
We have tested the best MagSafe chargers for iPhones and the best MagSafe power banks for iPhones. This reviews roundup now also includes 15W Qi2 and 25W Qi2.2 chargers as they arrive to market.
Some thicker cases get in the way of MagSafe wireless charging so make sure your iPhone’s case is MagSafe compatible—see our roundup of the best iPhone 15 Cases, best iPhone 16 cases, best iPhone 17 cases and best iPhone 18 cases.
Wireless charging is great, but it’s not as fast as wired charging. For truly fast iPhone charging, use a cable connected to at least a 20W USB-C charger. For the iPhone 15 and later that means a USB-C to USB-C cable; for older iPhones you’ll need a USB-C to Lightning cable. A USB-A to Lightning cable won’t offer iPhone fast charging. Click here for more iPhone fast-charging tips.
Somewhat confusingly, MagSafe is also the name for Apple’s wired-charging standard for its MacBooks—connecting the charging cable to the MacBook’s MagSafe port via magnets, meaning it is not only easy to connect but, if accidentally disconnected, it pops out rather than dragging your laptop to the floor. This version of MagSafe is magnetic and safe and has a charging connection for MacBooks but is not wireless. We explain the difference between MagSafe on Mac and MagSafe on iPhones in our Complete guide to Apple MagSafe: What is MagSafe?
MagSafe wireless charging is built into the iPhone 12, 13, 14, 15, 16, 17, and 18 families, with the exception of the 16e. It’s also supported by the iPhone Air and iPhone Duo.
Foundry
Qi2 (“chee too”) is the latest version of the Qi “energy flow” wireless charging standard, and it’s supported by all iPhones from the iPhone 12.
Famed for its “Not Invented Here” strategy, Apple can be quite precious about adopting other technical standards. It has a long history of rejecting any idea that didn’t originate within Apple itself. However, thankfully Apple has cooperated with the creation of Qi2 to the extent that in effect it gave the Wireless Power Consortium (WPC) MagSafe to use as the basis for Qi2’s Magnetic Power Profile that defines how the new generation Qi works. Apple is a WPC “steering member” and chair of the board of directors.
Think of Qi2 as not just MagSafe for Android, but MagSafe benefits for all compatible wireless charging products.
Qi2 means chargers won’t have to be certified by Apple to support 15W charging. They should, however, meet the technical demands of the WPC. In short, a Qi2 charger will deliver twice as fast charging as “MagSafe-compatible” chargers.
As MagSafe certification costs manufacturers a fee to Apple, removing this should result in cheaper chargers that match Apple-certified chargers in terms of speed.
Qi2 wireless charging works with all iPhones 12. and onwards, except the 16e.
Simon Jary / Foundry
Qi2 25W is the latest version of the Qi “energy flow” wireless charging standard. Its technical name is Qi2.2.
It started rolling out in wireless charging products from the mid-2025 and is now seen in many new wireless charging products.
Qi2 25W means chargers can support up to 25W wireless charging. They have to meet the technical demands of the WPC. In short, a Qi2 25W charger will deliver 10W more power than Qi2 and 3.3 times as fast charging as MagSafe-compatible chargers.
The use of a Magnetic Power Profile (MPP) provides better alignment but also reduces magnetic field leakage caused by misalignment. This minimizes the build-up of heat and ensures optimal charging efficiency. A ±0.5mm magnetic alignment precision improves charging efficiency by “up to 40%”, according to manufacturer Baseus.
Qi2 25W products also feature next-generation thermal regulation with stricter 40°C surface limits and enhanced coil layouts. This ensures that less energy is wasted and provides 15% better charging efficiency—even in motion or with slight misalignment.
Qi2 25W wireless charging will work with the iPhone 16 family and later (except the 16e and 17e). The iPhone Air supports Qi2 25W but only up to 20W, which is likely caused by the super-thin phone’s thermal management. The iPhone 16 and 16 Pro can make it to only 22W according to Apple. The iPhone Duo does support 25W Qi2.2.
For Qi2 25W to work at full 25W supporting iPhones must have installed at least iOS 26 or later.
First, MagSafe, Qi2 and Qi2 25W are all better than plain Qi. Owing in large part to their magnetic connection, they are more efficient and definitely offer faster wireless charging than Qi.
For all extents and purposes, Qi2 looks pretty identical to MagSafe so iPhone 12/13/14/15 users can choose between MagSafe or Qi2 without fear. iPhone 16/17/18/Air/Duo owners, however, should look to MagSafe or Qi2 25W, as Apple’s own MagSafe Charger and soon Qi2 25W chargers can reach charging speeds of up to 25W when paired with the latest range of iPhones.
All should clamp chargers magnetically to the iPhone in the same way and allow for between 15W and 25W wireless charging.
Although technically very similar, Apple is likely to still require MagSafe certification for non-Qi2 products to reach 15W wireless charging. Both the charger and the device must be certified for Qi2 for it to work at 15W, in the same way as MagSafe. However, it is likely that future MagSafe-certified products will also be certified for Qi2, and post iOS 17.2 all iPhones (except 16e) will work natively with Qi2 and Qi2.2 chargers.
For consumers it’s a win-win as Qi2 and Qi2 25W means faster wireless charging will be brought to more devices and people. For product marketers it may be a bit of a labelling nightmare until all the chargeable devices catch up with the technology: expect MagSafe Compatible (7.5W), MagSafe (15W or 25W), Qi2 15W (15W) and Qi2 25W or Qi2.2 (25W).
As the Wireless Power Consortium used Apple technology to build the Qi2 specification, it is true that Qi2 matches MagSafe for speed. Both can charge at up to 15W and use the largely same magnetic attachment tech. Note the 25W charging potential of the Apple MagSafe Charger and iPhone 16/17, plus the same charging speed from Qi2 25W.
The first Qi2 charger we tested and reviewed at Macworld was the Anker MagGo 3-in-1 Wireless Charging Station. We tested its Qi2 wireless charging speed by charging an iPhone 15 Pro all the way to a 100% full charge, and taking timings at 30%, 50% and 80%. We did the same using a Apple’s own MagSafe Charger and also via a straight wired USB-C connection.
The fastest way to charge an iPhone is via a wired connection: USB-C to Lightning for iPhones older than the iPhone 15, and USB-C to USB-C for the iPhone 15 and later. The average wired-charging time in our tests was 25 minutes to 50%, 55 minutes to 80% and 70 minutes to 100%.
Our wireless charging tests for officially Apple-certified MagSafe chargers (using Apple’s own Wireless Charger) and for Qi2 magnetic wireless charging (using the Anker MagGo) had remarkably similar timings. There was some variance either way but also small differences using the same charger so we are confident that using these two magentic wireless charging technologies came up with the same basic results on average: 45 minutes to 50%, 90 minutes to 80% and 115 minutes to 100%.
In summary, then, MagSafe and Qi2 charging at 15W results in the same times and so can be considered equal—except for the 25W MagSafe potential of the iPhone 16/17–and the same from Qi2 25W now it is released. And, again as expected, merely MagSafe-compatible chargers took twice as long as the 15W chargers: 45 minutes to 30%, and 90 minutes to 50%.
Our tests demonstate that Qi2 25W will charges an iPhone 16 Pro from 0–50% in just over 30 minutes—manufacturers often claim 25 minutes but that is under clinical conditions. In Macworld’s real-world tests 32-34 minutes is the average. In comparison, a Qi2 15W charger generally takes about 45 minutes to reach the same level—this would work out as the 25W option being around 45% faster than the 15W chargers. Wireless charging depends on many factors, such as device settings, usage during charging, and ambient temperature.
Don’t concern yourself greatly about the 22W limit of the iPhone 16 and 16 Pro. The 3% difference between that and 25W is marginal.
Batteries charge slower the fuller they get, especially in the last 10–20% of charging. The fuller the battery is, the slower it absorbs energy.
To start with, a Lithium-Ion battery accepts whatever current it can, but as the battery gets closer to being full it accepts less current, and so the power being transferred tapers off.
Imagine you were filling up a glass with water. You can start with the faucet or tap at full blast, but as the glass gets fuller, you have to slow the flow down to avoid the water spilling over, until eventually just a trickle of water goes in as you try to get it right up to the brim.
If the battery didn’t charge this way and instead filled up at full blast till reaching 100%, it would get very hot and you’d risk damaging it to the point it might explode!
Slowing down the charge when the battery is getting closer to full also increases the number of charge cycles a battery can go through before it permanently loses capacity.
Taking advantage of this, if you need to charge quickly, stop at 80%, use the device for a while and then top back up to 80% before the charging speed starts to slow.
Ugreen
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The SolidSafe Air is the equal-slimmest semi-solid-state 5K Qi2 power bank you can buy—indeed, if you want the slimmest magnetic wireless power bank this is your first stop. And it impressed us in our iPhone recharging tests, being just 1% off the current champion.
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I still own power banks that I struggle to grip in one hand. Such items lurk in the bottom of a cupboard awaiting only the end of days rather than a long train journey or city break vacation.
Batteries have been getting smaller for years, but recent advances have slimmed phone power banks to shirt-pocket size.
Solid-state electrolytes are replacing flammable liquid electrolytes with more stable, efficient materials that allow for smaller, more compact, and safer battery designs. While we haven’t tested any fully solid-state power banks, we have been seeing semi-solid-state cells where flammable liquid is reduced to a fraction of that found in standard lithium-ion batteries.
It’s not all about size—these batteries are safer and should last significantly longer with a greater number of cycles before the battery degrades.
BMX
But size does matter when you’re carrying the power bank in your pocket or backpack.
BMX, not the little trick bicycle ridden by kids and hipsters but a company called Better Mobile Xperience, has just released a new magnetic wireless power bank that it claims is the “world’s thinnest” 5,000mAh Qi2 power bank.
The SolidSafe Air 5K doesn’t stray far from the usual length and width of today’s magnetic wireless power banks (4.1 x 2.8 inches / 103 x 70mm), but when it comes to depth (or height, however you look at it) it is truly tiny at just 0.27 inches (6.8mm).
In comparison, the iPhone Air is only slightly thinner at 5.6mm, with a 3149mAh (12.4Wh) battery capacity.
While we haven’t tested every single wireless power bank model that exists, we pride ourselves in checking out all those from our most trusted power brands, including Anker, Ugreen, Belkin, EcoFlow, Baseus, Kuxiu, ESR, Zens, Statik and more.
The margin might be coming down in size, but the SolidSafe Air 5K does indeed live up to BMX’s claim, although the Baseus Picogo Air Magnetic Power Bank (AM71) matches it on slimness if not quite on performance (82% vs 89%).
The closest we have measured in terms of slimness are:
Clearly, the SolidSafe Air is the thinnest 5K magnetic wireless power bank that we have tested, alongside the non-solid-state Baseus AM71.
Simon Jary
What about its weight? When it’s on your person or in the bag you are carrying, weight is as important as size; if not more. The SolidSafe Air weighs 4.1oz (116g); to compare, the iPhone Air weighs 165g.
Let’s compare that to our other slim power banks mentioned above.
The SolidSafe Air is therefore not the lightest power bank we’ve tested. That honor goes to the Baseus PicoGo Air.
However, we don’t think 0.4oz or 11g is going to be noticeable by anything other than a set of precision scales.
BMX
The SolidSafe Air is so thin that the magnetic coil must be raised a little from the otherwise flat surface of the power bank.
Looking at the distance between the USB-C charging port and the sides makes me think it will be nearly impossible to get any thinner—but, fear not, someone will.
BMX
It’s now available in a choice of five colors: Gold, Black, Silver, Burgundy, and Glacier. That covers all the equally thin iPhone Air and now iPhone 18 Pro models with the latest Glacier and Burgundy colors.
BMX
The battery indicator is the standard set of four LEDs to let you know how much power is left in the power bank’s battery. One of the thinnest power banks we’ve reviewed is the PhoneSuit Elite Mag Slim 5K, and this boasts a digital percentage display, which is far more accurate, but such display on a 5K power bank is are, and to its credit, the SolidSafe Air’s LEDs are brighter than most.
The SolidSafe Air is reinforced with titanium to make it more durable against impact. That combined with the safer semi-solid electrolytes should make the power bank inherently safer than most power banks.
Semi-solid-state cell technology reducing flammable liquid content improves thermal stability and lowers fire risk compared to conventional lithium-ion batteries. It should also mean the SolidSafe Air can be charged, discharged and recharged many more times than a traditional lithium-ion power bank.
The 5000mAh (milliamp hour) battery is rated at 18.5Wh (watt hours). This is the sweet spot for a power bank that is lightweight and slim but still has enough capacity to offer a decent iPhone recharge. Remember the iPhone Air’s battery capacity is 3149mAh (12.4Wh). The closer match is the iPhone 17 Pro Max’s 5088mAh (20Wh) battery. Find out your iPhone’s battery capacity in our long list.
We test power banks by running down an iPhone 16 Pro to 0% and seeing to what percentage the power bank can take the phone’s battery. In this test the BMX SolidSafe Air 5K achieved an impressive score of 89%, among the highest of all the magnetic wireless power banks we have had in the Macworld Labs.
Simon Jary
The SolidSafe Air employs the Qi2 magnetic charging technology, so can supply up to 15W of power wirelessly.
Some larger 10K power banks—such as the Kuxiu K1, Baseus PicoGo 25W 10K, Ugreen MagFlow and Sharge Icemag 3—use the newer Qi2.2 tech that can handle 25W for compatible iPhones (iPhone 16 and later). 25W should charge an iPhone (16 or later) from 0-50% in around half an hour, while 15W takes about 45 minutes. We are still waiting for a 5K power bank that is as fast as 25W.
Use the charging port with a cable (USB-C to USB-C for iPhone 15 and later, USB-C to Lightning for older iPhones) to gain a little faster 20W of power. A neat function is simultaneous wired (using a cable in the power bank’s charging port) and wireless charging. Via this method you get 10W wired plus 12W wireless for 22W power—not so far off the 25W that Qi2.2 would have supplied.
The power bank itself is charged at up to 15W, which is quite slow in comparison to others that have input speeds of between 18-30W. if charging overnight or not in a hurry, this shouldn’t matter. A full recharge of the power bank should take around 2 hours.
The SolidSafe Air 5K Solid-State Qi2 Power Bank is available on the BMX website for $59.99, with Amazon sales starting at the end of March.
For alternatives check our reviews of the best magnetic wireless power banks.
The titanium SolidSafe Air is wafer-thin and can slip into a shirt pocket without worrying the stitching. You can charge your iPhone (12 and later) wirelessly at 15W or 22W when using both wired and wireless outputs, which is fast. There are power banks that recharge themselves faster, and power banks with smarter battery displays, but the BMX SolidSafe Air is the slimmest semi-solid-state 5K Qi2 power bank you can buy—indeed, in our experience, it’s both one of the slimmest and lightest magnetic wireless power banks on the market.
The world’s first demonstration of a subsea geothermal power plant has taken place near an active underwater volcano almost a mile below the ocean surface. It generated less than 10 seconds of net-positive electricity but showed the technical feasibility of tapping another form of renewable energy underwater.
The three-week test deployment of the 3-ton prototype power plant took place at the Axial Seamount in the northeast Pacific Ocean in September. Endurance Energy, the Seattle-based startup behind the effort, aims to eventually commercialize subsea geothermal power for Pacific island nations and other customers looking for alternatives to importing expensive fossil fuels.
“The deep ocean gives us unlimited cold seawater for cooling, and its weight keeps the system and the well pressurized, so our plants can be compact,” said Andrew Redd, founder and CEO of Endurance Energy, in an email to Ars.
© Endurance Energy
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A drawback of using an HDR-ready third-party monitor on macOS 26 Tahoe was the inability to activate High Dynamic Range at the common 2560 x 1440 scaled resolution. Fortunately, the newest macOS release resolves this problem.
- Symptom: scrolling is choppy on the Studio Display XDR at 120Hz or Adaptive (47–120Hz). At 60Hz, and on the MacBook’s own screen, scrolling is smooth.
- What devices are affected: M5 Pro MacBook Pros have reproduced the problem; other repots suggest the Mac mini with M5 Pro chip is also affected. Apple lists M5 Pro MacBook Pro models as supporting the Studio Display XDR at 120Hz.
- Likely cause: measurements suggest the GPU stays at a low clock speed while scrolling and misses frame deadlines.
- Workaround: MacRumors Forums poster Tiguanito’s M5ScrollBoost, a small menu bar app that encourages the GPU to run faster while you scroll.
Previously:
Update (2026-10-14): Timuçin Kabak:
Another issue I encountered is that the True Tone also applies to some external displays and applies a tint. I created a tool for it.
For centuries, civilizations have harnessed energy from water. However, hydropower often requires large bodies of water to move heavy machinery, confining its use to rivers. But what if the electricity needed to light up your house could be generated from raindrops hitting its roof?
To achieve this, scientists rely on electrical charges created when materials come into contact and then separate, a phenomenon called the triboelectric effect. As an example, rubbing a balloon against your hair gives them opposite charges, causing your hair to stand up and stick to the balloon. Scientists apply the same principle to make droplet-based triboelectric nanogenerators, or D-TENGS, where raindrops slide across negatively charged surfaces. As the droplets move, their positive charges gather near the surface, freeing up their negative charges. When the droplets reach a metal strip called an electrode, these negative charges flow into a circuit, generating electricity. However, water often remains on D-TENG electrode surfaces, blocking subsequent droplets and corroding the device.
Researchers at the China Three Gorges University and the Chinese Academy of Sciences approached this problem by modifying the shape of the electrodes used in D-TENGs. They proposed that a needle rather than a strip would help droplets detach quickly, allowing charge to flow into a device that uses inexpensive components. They called this design a needle electrode droplet-based triboelectric nanogenerator, or NED-TENG.
To build the NED-TENG, the researchers prepared a plastic film using a water-repellent polymer called polytetrafluoroethylene as the negatively charged surface. They inserted a copper wire through the center of the plastic film, protruding 3 millimeters (0.1 inches) from the front side to form the needle-shaped electrode exposed to raindrops. Meanwhile, they attached copper foil to the plastic film’s backside as a second electrode, completing the circuit. The team connected both electrodes to an instrument that measures electrical performance and mounted the components on an acrylic sheet, sealing it with waterproof tape.
To simulate raindrops, the team inclined the NED-TENG at 50° from a table and dispensed tap water drop by drop from 30 centimeters (12 inches) above its plastic film. Like conventional D-TENGs, the device generated electricity as droplets slid across the film and contacted the needle electrode. However, because the water touched only a small area of the needle, it easily slid off the NED-TENG, preventing the water from building up like in D-TENGs.
The researchers then evaluated and optimized the device using 2 metrics: the force driving charges through its circuit, or voltage, and how fast its charges transfer, or current. First, they compared the NED-TENG with a conventional D-TENG. The NED-TENG generated about 564 Volts (V) and 5 milliamperes (mA) of current, nearly twice the voltage and 3 times the current of the D-TENG, and enough to power small electronics like indicator lights.
Next, they varied the droplets’ release height to maximize electricity production. They found that increasing the release height from 10 to 30 centimeters (4 to 12 inches) increased both voltage and current, peaking at about 543 V and 4 mA. At greater heights, droplets splashed hard on impact, scattering the water and disrupting the charging process they observed in sliding droplets.
Similarly, the researchers tested different device inclination angles, ranging from 10° to 70°. Their tests revealed that the device’s electrical performance increased at steeper angles and peaked at 50°, reaching 521 V and 3 mA. At steeper angles, droplets spent less time in contact with the surface, reducing electrical output. They explained that because triboelectric materials are highly sensitive, results can vary slightly between experiments, leading to individual peak values that are lower than the highest overall outputs.
The researchers then explored how the technology might perform in a simulated rooftop installation. To reduce power fluctuations during real-world applications, they connected multiple NED-TENGs. They observed that 10 connected devices could fill a small energy-storage component within 2 minutes and power 200 LED lights.
Overall, the NED-TENGs shed water efficiently and generated more electricity than D-TENGs, while remaining simple to build. The team noted that future upscaled studies should examine how rooftop systems can direct rainwater onto the devices at optimal heights, and how droplets interact with their surfaces to improve long-term performance. With further development, these low-cost systems could turn rooftops into practical generators powered by everyday rainfall.
The post Needles turn rain into electricity appeared first on Sciworthy.
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Opposition to wind farms is fuelling support for Alternative for Germany (AfD), with locals who protest that their country "is not a wind farm" turning to the climate sceptic party, which has pledged to tear them down.
The post Wind Farm Opposition Fuels AfD Support as Party Pledges to “Tear Them Down” appeared first on The Daily Sceptic.
-30 %
Smartes 45-Watt-Ladegerät zum Amazon-Tiefstpreis
Nur 27,98 Euro statt 39,99 Euro UVP
Viele Hersteller, auch Apple, legen ihrem Smartphone kein Netzteil mehr bei. Deshalb ist es wichtig, dass Sie das richtige kaufen. Kompakte GaN-Modelle beispielsweise eignen sich dabei nicht nur für Handys, sondern können je nach Leistungsbedarf auch Tablets, Smartwatches und kleinere Notebooks versorgen.
Das Anker Nano USB-C-Ladegerät mit 45 Watt und Smart Display ist bei Amazon aktuell für nur 27,98 Euro erhältlich. Gegenüber der unverbindlichen Preisempfehlung von 39,99 Euro sparen Sie 30 Prozent. Damit liegt das Netzteil auf seinem bisherigen Tiefstpreis. Ähnlich günstig (nur einen Cent teurer), war es zuletzt Mitte August, in der Zwischenseit stieg der Preis auf 34 Euro bis UVP an.
Der Angebotspreis gilt für alle vier Farben: Schwarz, Weiß, Blau und Orange.
Das Ladegerät stellt über seinen einzelnen USB-C-Anschluss bis zu 45 Watt bereit. Ein intelligentes dreistufiges System soll die abgegebene Leistung in Echtzeit an das verbundene Gerät anpassen. Laut Anker lässt sich ein iPhone 17 Pro damit innerhalb von 20 Minuten von 0 auf 50 Prozent laden. Dieser Wert basiert allerdings auf internen Labortests, sodass die tatsächliche Ladezeit unter anderem von Gerät, Temperatur und Nutzung abhängen kann.
Eine Besonderheit ist die automatische Erkennung aktueller Apple‑Geräte. Das Ladegerät erkennt nach Angaben des Herstellers die iPhone-17-, iPhone-16- und iPhone-15-Serie sowie verschiedene iPad-Pro-Modelle. Unterstützt werden das iPad Pro 11 Zoll aus den Jahren 2020–2024, das iPad Pro 12,9 Zoll aus den Jahren 2020-2022 sowie das iPad Pro 13 Zoll von 2024.
Andere Geräte wie Samsung-Smartphones, Macbooks, Apple Watches oder Airpods können Sie grundsätzlich ebenfalls laden. Die intelligente Erkennung und die angepasste Anzeige stehen jedoch nur bei den ausdrücklich kompatiblen Modellen zur Verfügung.
Auf dem integrierten Display können Sie unter anderem die aktuelle Ladeleistung, die Temperatur und den Ladestatus ablesen. Ergänzend zeigt das Netzteil kleine Animationen an. Das Display können Sie passend zur Ausrichtung des Ladegeräts drehen. Dazu muss die entsprechende Bedienfläche laut Anker zwei Sekunden lang gedrückt werden.
Für das Laden über Nacht besitzt das Netzteil einen TÜV-zertifizierten Schonmodus, den Anker als Care Mode bezeichnet. Er wird durch doppeltes Antippen aktiviert und soll die Wärmeentwicklung reduzieren. Anker spricht davon, dass das Ladegerät bis zu 20 Grad Celsius und der Akku des angeschlossenen Geräts bis zu 5 Grad Celsius kühler bleiben können.
Mit 27,99 Euro erreicht das smarte Anker Nano erneut seinen bisherigen Tiefstpreis. Interessant ist das Modell vor allem für Nutzer aktueller iPhones und iPads, die ein kompaktes Ladegerät mit Leistungsanzeige und zusätzlichem Schonmodus suchen. Auch die Auswahl aus vier Farben ist ungewöhnlich, da Netzteile häufig nur in Schwarz oder Weiß angeboten werden.
Bei Amazon kommt das Modell auf 4,7 von 5 Sternen bei über2.000 Bewertungen. Mehr als 1.000 Modelle wurden im vergangenen Monat gekauft, zudem wird das Ladegerät als “Amazons Tipp” geführt. Nutzer loben vor allem die Verarbeitung, das kompakte Gehäuse, die Ladegeschwindigkeit und das gut ablesbare Display. Auch die auf Apple-Geräte zugeschnittenen Funktionen werden positiv bewertet.
Beim Preis gehen die Meinungen dagegen auseinander, was angesichts der regulären UVP von knapp 40 Euro nachvollziehbar ist.
Weniger geeignet ist das Modell für Nutzer, die mehrere Geräte gleichzeitig laden möchten, da nur ein USB-C-Anschluss vorhanden ist. Auch Besitzer älterer Geräte mit Lightning-Anschluss profitieren möglicherweise nicht von der automatischen Erkennung und der Displayanzeige. Hinzu kommt, dass kein Kabel mitgeliefert wird – dies müssen Sie also zusätzlich kaufen.
© Jeff Chiu/Associated Press
In the badlands of Chakwal, in north-central Pakistan, Bestway Cement is transforming plots of dry earth and olive and peach groves into a forest of solar panels.
Its efforts will add 6.34 megawatts of generation capacity by the end of the year, the company says, in addition to the 26 MW of photovoltaic cells currently in place. Already, solar generates over a quarter of the electricity powering its cement plant.
“It’s the only way we can compete,” says Abdul Waheed, the general manager at Chakwal, which produces over 3 million tonnes of cement per year. “Our rivals have already gone in this direction.”
© Julián Trejo Bax/Associated Press
Oracle’s proposed investment in 2 gigawatts of renewable energy projects for New Mexico comes as local opposition could delay development of the Project Jupiter data center that Oracle is building for OpenAI.
The two tech companies are developing the $165 billion Project Jupiter data center in Santa Teresa, New Mexico, as part of the broader Stargate AI infrastructure project announced by President Donald Trump in 2025. But Project Jupiter faces local protests and court battles over concerns about its environmental impacts—and the latest Oracle announcement on September 8 seeking proposals for renewable energy projects does not change the fact that the data center will be powered by fuel cells that consume natural gas.
“Like all matching programs, this would be synthetic in the sense that 2 GW of renewables wouldn't directly power the data center,” wrote Michael Thomas, CEO of the Cleanview data platform that tracks renewable energy and data center projects, in a LinkedIn post.
© STACK Infrastructure
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