For an average untrained male cyclist who is 175lb, they should be able to maintain 1.5-2 w/kg over an hour, or 120-160watts. A beginner cyclist who's been cycling recreationally over over a year should be able to attain 2-2.5w/kg which is 160-200 watts. A recreational cyclist who's be training for several years should be able to maintain 200 watts.
Trust me, I'm a cyclist, and I cycle with a power meter.
If you are not chasing watts, it’s much more sustainable to do 70 watts for two hours. You can probably do this every day.
Basically, you can probably charge your macbook at peek power for an hour every other day, or every day for a short while if you're okay with burning out eventually.
Expect to need to eat 400-600 calories and a lot of water each time you do this.
But that was 35 years ago and it was a high school physics experiment meant to be entertaining more than precise.
Considering the difficulty of sustaining 700 watts vs 350 watts, we could've had some very well-burnt toast if they uninstalled the heating coils for the 2nd piece of bread!
While watching the video, I was wondering how they modified the >1kW device to produce a toasted toast in that short amount of time (I guess you could substitute instantaneous power for time up to a point, but the video wasn't that long), thinking maybe they removed one of the sides' circuits. Now I'm disappointed as well. Thanks xD