Expected incremental backup performance on Mid-2015 MacBook Pro I use Acronis True Image backup software on a new mid-2015 MacBook Pro Retina with a 2.8GHz processor and a 1TB SSD running High Sierra and APFS.  Incremental backups, even when there's almost no files that are changed on my system, take about 30 minutes to scan ~300GB.  Almost all of this is scanning time to look for changes.  Activity Monitor's Energy tab reports Energy Impact of about 150. 

Is this normal?  Seems like a long time and a lot of battery expenditure (if I enabled backups while not plugged in) for a disk scan.

Also, are there other less battery-intensive backup software for Macs?  Or should I realistically expect any backup system to be a time and resource hog because a full disk scan is inherently energy-intensive and time-consuming?

Finally, is there anything I can do (other than removing files from my disk or excluding them from backups!) to improve backup times and/or energy cost?
With those sorts of times it would appear that Acronis does a brute-force scan of the whole filesystem comparing each file.

But since 10.7 (Lion) macOS provides a mechanism called FSEvents that allows an app to be notified about changes so it can do its job in a much more efficient way. Time Machine uses FSEvents.

So, to answer your question: Your times are about right for software that is doing the scan inefficiently. As a Time Machine user I see far shorter times for much more data (600GB on SSD to external 1TB HDD over Thunderbolt) using my 3GHz i7 MacBook Pro (Retina, 13-inch, Early 2013) running High Sierra and APFS.

My recommendation is that you change software to one that is more modern in its approach.

PS: Time Machine would backup your old Mac and restore to a new Mac, though it does it using its usual loose files approach rather than a single monolithic image. It would also only backup changes to your Parallels VM – no such luck for a VMware Fusion user like myself.