I hopped 500 miles (to wash my clothes)
For some unknown reason I watched this video on facebook about a washing machine that you power by pumping a pedal. It´s a well made video and a neat looking product but some incorrect use of terminology.
500 Watts per cycle just doesn´t make sense.
500 Watts is the energy per unit time so the longer the cycle the more energy is used. A washing machine cycle is about 1 hour (says he who knows nothing about the operation of a washing machine) so 500 watts for one hour is 1.8 MJ, that´s 430 kcal. Now this all has to be done with one foot so its equivalent to about 40 minutes of hopping on a running machine. Not an inconsiderable amount of effort. Of course the foot version is smaller, uses cold / preheated water (I guess).
Interestingly the actual video made by the company producing the machine makes no reference to 500 Watts. I also visited the Yirego website and discovered that the cycle is only 3 minutes so a bit less than 500 miles. I remember we used to take blow up mattresses camping and inflate them with a foot pump, very tiring.
and some music
Tags: conservation of energy