Well I went from a vented with 1kW and 2 kW options, to a heat pump which uses 600 watt, and comparing the vented at 1 kW which would take around 90 minutes, nothing automated so if not dry we would put it back on for 30 minutes, with the heat pump which takes 180 minutes although some loads it does run a mark/space ratio near the end, the gain power used wise between the two is very little.
However, there are other considerations, not leaving a window open with the hose out of it. And as a result, mould in the room, a drain pipe in with the washing machine drain is far better.
In the main condenser, dryers do not give an option as to power used, but those using the rooms air to condense will clearly warm up the room, and those using water, clearly waste water, and both tend to run very hot, so the heat pump condenser does not heat the room that much, and it runs cooler which is general is better for the clothes, but also longer which is not so good for the clothes.
Overnight, the electric costs me 8.5p/kWh, during the day it cost 15p/kWh in lost export, and I feel happier running a heat pump dryer overnight to any other type. The dryer we have when timer is set, tumbles the clothes every so often while waiting for time to start, and the timer starts in ½ hour increments then moves to 1 hour increments, we have 5 hours off-peak so not a problem, but some tariffs are down to 3 hours off-peak, so ensure the dryer runs within that time frame could cause a problem.
I note the model after mine connects to the internet, I assume, so one can switch it on when the sun shines? At least more accurate start times with delay start. I can't use a smart socket adaptor as if power cycled off/on it auto switches off.
The drum is bigger as to the old vented, so it will take the whole load from the washing machine, but the paddles in the drum can catch on any pull cords in the clothes. Cleaning filters is easy, and not too noisy, which is important if running overnight. Make of mine is Haier, first one went faulty, there was no problem getting it exchanged FOC, after 9 months.
There are 14 programs, not sure why, as either 50-55°C or 60-65°C for them all, default times change, but since it monitors how dry, that seems pointless so we have Cupboard, ready to ware, and Ironing option.