What I did find interesting is that it's not actually environmentally unfriendly, because the hot energy is stored in a very well insulated manner, and because it's near 100% efficient in the amount of water heated/used (whereas in a regular kettle you tend to overboil and boil too much water, and in an electric kettle there's often even a minimum fill that's larger than the needed water).
At least that's the story I've been reading on unaffiliated websites.
