A heat-pump condenser tumble dryer is by far the most economical energy-wise. We bought the full range Miele (to replace the full set Zanussi), extractor, dishwasher, washing machine, oven, fridge and this tumble dryer:
The quality and the economy are times better that our previous Zanussi one.
The washing machine had the motherboard replaced under warranty but since then it has been fine. Our electricity bill as well as water consumption dropped significantly.
It was an expensive investment and it took deliberation as Miele is not what it used to be 15 years ago with 10 year warranty. The claim is they have been stress tested for 20 years continuous use.
Miele have quite serious discounts around Black Friday and Christmas, something I missed.
Good luck with your next purchase.