How can apple tell if the energy grid I’m on is clean or not?

Your iPhone forcasts the energy that is on the grid:

When Clean Energy Charging is enabled and you connect your iPhone to a charger, your iPhone gets a forecast of the carbon emissions in your local energy grid and uses it to charge your iPhone during times of cleaner energy production.

Well, apparently your information isn’t any more accurate than what’s on the internet. I plugged my phone in to charge when I went to bed last night and this Clean Energy thing popped up. I read it and decided to leave it on. My battery was at 51%. When I woke up this morning it was at 49%.

they use their knowledge of power production various places and when it peaks in terms of renewable power

What Is Clean Energy Charging on iPhone and How Does It Work? (makeuseof.com)

which is why it's only a thing in usa and is not likely to be a global feature

This topic has suddenly become viral on the internet after an article by Bloomberg and there are tons of disinformation and outright nonsense floating around about the feature. What you need to know is that the feature does not in any way slow down charging, delay charging, stop charging, decrease charging, or anything else that would negatively affect your iPhone or battery life.

Here’s another article about it.

https://appleinsider.com/articles/23/03/01/iphone-clean-energy-charging---everything-you-need-to-know

@lkrupp

I’ve been having trouble getting my iPhone to fully charge. I wake up and see the battery at 55-65%. I opened a support case, went back and forth with support, and they suggested trying different cables/chargers. I did that, no difference.

Today, while my phone was still plugged in and in non-charging state (stuck at 56%), I tried enabling then disabling “clean charging”, and presto! It charged right up.

This phone is only a few months old, and the battery life is already down to 96. That’s probably because I’d often end up draining it down to 10% or so, BECAUSE IT NEVER FULLY CHARGED TO BEGIN WITH.

Maybe if it wasn’t for whatever bug I’ve encountered, this “feature” wouldn’t have impacted my battery life in a negative way. But it did. And it’s frustrating how much time I’ve wasted tracking it down, when I explicitly disabled the feature, since I’m off-grid.

Correlation does not imply causation, a primary tenant of logic. Clean energy charging has absolutely nothing to do with your issue, period. That’s the disinformation being spread about this feature, that it causes iPhones to not charge... it doesn’t. Some disinformation even claims it bricks iPhones... also nonsense.