The actual toast from experiment. 🙂

Steve of Canadian Energy Issues brought this CBC **Podcast**** ****(****Skip ahead to 00:24:45)** to my attention. Ed Begley, actor and environmentalist makes toast from his pedal generator.

I know a toaster needs a lot of power so wanted to work through the numbers.

Okay, I’m making toast as I write this. My toast has been going for a minute as I type this sentence.

I found a table of appliance consumption (toasters take 800-1500 Watts so **1000 Watts** seems like a good number for arguement).

03:15 Dinnnnnnnnnnnnnnnnnggg! I learned something. **Toast takes about 3 minutes** from cold.

**Ed pedals 15m to make toast. **That’s 5x longer than the 3m cook time. So he can put out **1/5th the toaster requiremen**t. In other words it will take **18m** to make the toast. Fifteen minutes of frantic pedaling (energy being stored) and then 3m to run the toaster.

So he needs to pedal at **200 Watts** (1/5th of 1000 Watts) for 15m if he has an efficient electricity storage system attached to his bike.

To try and see how reasonable that is lets do some comparisons. A person can make about 1/10th horsepower over extended periods. A horsepower is about 746 Watts so 200W is about 1/4 horsepower.

1/4 hp for a short period seems plausible to me. In fact I’ve seen projects that require even more human input. The Gossamer Albotross pedal powered plane requires 0.4 hp and a human pedaled it across the English Channel in just under 3h.

Let’s put 200 Watts into some familiar terms so we can **“Feel the Power”**.

A horsepower is 550 foot-pounds/second (you can lift 550 pounds one foot in one second, or one pound 550 feet in one second). We need to do 1/4 of that so we’re talking **138 foot pounds per second**.

Fifteen minutes of pedaling is 900 seconds which means he is doing **124,200 foot pounds of work**.

I just googled Ed to see a picture of him to guess how much he weighs. I’m very scientific. 🙂 Um, okay he looks like a thin/fit guy so let’s give him 175lb. I understand he’d tall so perhaps we should kick another 15lb? Perhaps **190lb**?

To “Feel the Power” we need to divide 190lb into the 124,200 foot pounds and see how high to climb stairs in 15m. That comes to 654 feet. **That’s 65 floors in 15m.**

So to get a feel for how much this is, it’s a matter of finding a 70 floor building and running up the stairs in about 15m. That’s 4-5 floors per minute.

So it looks plausible, but don’t be fooled into thinking it’s easy. This calculation also suggests that it would take 5 people to make toast in real time using 1/4 horsepower each.