Use Your Bike as a Backup to Your Backup Power Supply

Re:Use Your Bike as a Backup to Your Backup Power Supply by Someone on Sunday October 25, 2020 @09:09PM (#24891827)

The math never works out, by a long stretch. Electricity is just too cheap and humans too weak.

“One kWh” sounds like a tiny amount, but it is 3,600,000 joules. If you want to store that as potential energy, you must (taking g=10m/s²) lift a mass of 360,000 kilograms by a meter.

Another way to see how large a kWh is: a human body, ballpark, needs 3kWh per day (125W an hour)

⇒ If you want to produce 3kWh a day, you’d have to eat twice what you normally eat.

And that, even ignoring heating and airconditioning, doesn’t power an average household in the western world.

[ Parent | on HN ]

Re:Use Your Bike as a Backup to Your Backup Power Supply by adrianN on Monday October 26, 2020 @03:47AM (#24893720)

To put things even more into perspective: The average American uses about 10kW continuously on average.

(Primary power consumption in the US is about 10^20 Joules per year, that's around 9.7kW/person).

[ Parent | on HN ]