Using Significant Energy That's Not Good on the Safari!
Hey There I went on Safari there's a problem it's says This webpage was reloaded because it was using significant energy!
iMac 27″, macOS 10.13
The message is informative, and intended to alert you to the fact the webpage is burdening your Mac to the point it may be causing it to run slowly and (for portable Macs) its battery to deplete rapidly. The solution is to close the web page.