We are big fans of Heat Pumps. We have a whole-house heat pump for heating (and occasional cooling), and a heat pump water heater. Heat Pumps are extremely efficient because they do NOT create heat, rather they move it from one place to another. It is the same principle used in a refrigerator, which moves heat from inside the appliance to outside it, thus cooling the inside.

If you want, you can think that Heat Pumps "cheat". They take advantage of an external free energy source, like Sun radiation, and use that to heat your house, or water

There has been a LOT of progress in heat pumps over the last few years. The new ones work very well in a very large number of cases. Heat Pumps are prevalent in Scandinavian countries, and our weather is very mild in comparison to them.

The new Heat Pump Water Heaters are essentially drop-in replacements to your existing gas Water Heater; just more efficient and safer. They only need a 120V circuit.

And also look into the new Heat Pump Dryers. I particularly like the new Washer/Dryer combos. Very efficient in energy, and space! The new ones are much faster than the older models.

A quick check on the Home Depot website shows only very high end dryers that feature the heat pump technology. Oddly enough they all seem to be 240V. It sounds like they're still using electrical heating elements, otherwise why the 240V requirement?

240 is typical voltage for european appliances. Most high end appliances are european. Typical heat pumps run on 240. They use a lot of power.