from my own studies... In order from highest energy use to lowest energy use:
UK style Electric Kettle
Under cabinet Hot Tap
Hot Bottle Tap (Office Style)
Drip coffee Maker
Microwave
Pod coffee Maker
However, then we have the speed factor, with microwave amd hot tap both coming in first, the UK style kettle second and the pod running last.
So, for my solar situation, I have the following.. gas fire kettles that can be on wood, UK Kettle, because sometimes you need more than just a cup of coffee, the Pod system, and the microwave... I dont use the microwave however for hot water because of flashover... you put a spoon in it and because the surface was broken it suddenly turns into steam that boils on your hand, face etc.