Clean Energy Charging is not a conspiracy to reduce the speed or efficiency of charging when you plug in your iPhone. It is a harbinger of how most future electronics will consume power.
What is Clean Energy Charging?
Announced with iOS 16 and introduced in the US last fall, Clean Energy Charging selectively charges your device when lower carbon-emission electricity is available. In some regions, this might be during the daytime when solar and renewable energy production peak, but in most cases, it will be at night.
To support the feature, your iPhone gets a forecast of carbon emissions on your local energy grid. It then charges the device when the cleanest energy is available.