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A comment on Holland Puts a New Spin on Old Technology to Combat Climate Change. Parent comment
Edit: They could have their units mixed up or just measuring the peak output which is not the same as average output.
. Each time you pass through the door you generate enough power to make a cup of coffee.
Ben said on December 4th, 2008 at 4:46 pm
I call bullshit on this - there is no way one person generates the energy to heat a cup of coffee.
Energy needed = mass * temp raise * specific heat capacity = ~0.25kg * ~70C * 4.187 kJ/kgK = ~73kj
If it takes you a generous 10s to walk though the door you would need to be producing 73kj/10secs = 7.3kWatts!!!
According to http://www.ncbi.nlm.nih.gov/pubmed/10090637 the maximum a normal person can produce is ~500W so they are way off.
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Edit: They could have their units mixed up or just measuring the peak output which is not the same as average output.
. Each time you pass through the door you generate enough power to make a cup of coffee.
Ben said on December 4th, 2008 at 4:46 pm
I call bullshit on this - there is no way one person generates the energy to heat a cup of coffee.
Energy needed = mass * temp raise * specific heat capacity = ~0.25kg * ~70C * 4.187 kJ/kgK = ~73kj
If it takes you a generous 10s to walk though the door you would need to be producing 73kj/10secs = 7.3kWatts!!!
According to http://www.ncbi.nlm.nih.gov/pubmed/10090637 the maximum a normal person can produce is ~500W so they are way off.