Re: Water kettle energy consumption logging

legg <[email protected]> wrote:
> The common solution with 'flash heaters' is to turn the system 
> on x minutes prior to use and turn it off when the demand ceases.

Energy payback: W1*(t-tcool)+Wh =W2*t

Where:
W1 is the average wattage at lower T
W2 is the average wattage at 98°
t is the number of hours 
tcool is the time to cool down from 98° to T
Wh is the energy required to re-heat from T to 98°

W1, W2 are known from my previous 
tcool is unknown and I tried to guesstimate it
Wh is calculated as:

T° C to 98° C	Wh	Wh *1.25
90	37.24	46.55
80	83.8	104.75
60	176.91	221.14
After 6 hrs 21°	358.48	448.1

Second column from an online calculator. Wolfram Alpha as example. Third
accounts for the not perfect energy transfer. 

Solving for t is simple. Then the fun begins.