There is no such thing as "Human Power". Animals don't generate power, they just transform it from food via a roundabout process that produces lots of waste. There's just no way this is the most energy efficient way
In the best case, you can think of it like regenerative braking. You're recovering some of the energy that would normally be wasted on exercise machines in the gym.
Seems kind of pedantic. By this reasoning, almost all power sources are really fusion power, right? But we don't label solar, wind, fossil fuels, etc. as fusion.
The thing about human power is that exercise is also good for us, and in our current times most people (at least in developed countries) don't really get enough of it. So it doesn't necessarily have to be the most efficient to be useful.
> they just transform it from food via a roundabout process that produces lots of waste.
You mean like any other machine that generates power? A human on a bicycle, assuming a ~20% efficiency of converting food calories to muscle output, gets a gasoline equivalent 600-1000mpge (https://en.wikipedia.org/wiki/Bicycle_performance). And unlike a car, using a bicycle has health benefits.
Humans are a pathetically inefficient motor; Gasoline engines are around 30% efficient and battery-electric drivetrains are more than 90% efficient. A bicycle looks efficient because that inefficient motor is also pathetically low in power - a typical recreational cyclist can only sustain about 120 watts of output.
The leading vehicles in the Shell Eco-marathon routinely exceed 10,000 MPGe. PAC-Car II is the current world record holder, achieving 12,600 MPGe on hydrogen fuel.
Photovoltaic cells are also astonishingly more efficient than photosynthesis. The theoretical maximum efficiency of photosynthesis is ~11%, but most plants only achieve 3-6% efficiency. The leading commercially-available PV panels achieve ~22% efficiency and prototype concentrator PV cells have achieved over 46% efficiency.
Comparing these completely not road legal cars to technology from the 19th century is a stretch. I can legally ride my ~600MPGe bike on the streets TODAY. If PAC-CAR II equivalent cars are available to the mass market within our lifetimes, it will be impressive.
It would reduce my stress to imagine a world where my grandchildren didn't die from atrophy during the great power outage of 2079, where only the 10% of humanity that weren't reliant on exercise machines exercising their muscles for them, survived.
Covers a number of ways humans can actively (and passively) support their own energy use. Things like contributing waste to bio gas production, gym machines to mini generators, etc.
This article focuses on inventive ways to replace mechanical plants typical to large multi-story structures. It overlooks the mechanized power that would still be needed to grow and deliver food necessary to sustain that population density. Vertical gardening on the scale required is not at the same level of maturity as the human-power techniques the article describes.
Some years ago, an engineer gave a talk at the French National Assembly to a workgroup debating on sustainable energy. His point was that, by comparing the average yearly energy consumption of an occidental 1st-world person to the mechanical energy production of an average human being, each occidental would need about 200 slaves to maintain the same lifestyle. This is obviously not an qualitative equivalence but it helps put our way of life in perspective.
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[ 2.0 ms ] story [ 51.4 ms ] threadThe thing about human power is that exercise is also good for us, and in our current times most people (at least in developed countries) don't really get enough of it. So it doesn't necessarily have to be the most efficient to be useful.
You'll have to use energy to produce and distribute the food that powers the people that power the things...
Perhaps you would be better off if you simply used the energy to power the things.
You mean like any other machine that generates power? A human on a bicycle, assuming a ~20% efficiency of converting food calories to muscle output, gets a gasoline equivalent 600-1000mpge (https://en.wikipedia.org/wiki/Bicycle_performance). And unlike a car, using a bicycle has health benefits.
The leading vehicles in the Shell Eco-marathon routinely exceed 10,000 MPGe. PAC-Car II is the current world record holder, achieving 12,600 MPGe on hydrogen fuel.
Photovoltaic cells are also astonishingly more efficient than photosynthesis. The theoretical maximum efficiency of photosynthesis is ~11%, but most plants only achieve 3-6% efficiency. The leading commercially-available PV panels achieve ~22% efficiency and prototype concentrator PV cells have achieved over 46% efficiency.
(0.024 l/100 km, 0.019 l/100 km)
http://www.go-one.us/
(0.24 - 0.4 l/100 km)
It would reduce my stress to imagine a world where my grandchildren didn't die from atrophy during the great power outage of 2079, where only the 10% of humanity that weren't reliant on exercise machines exercising their muscles for them, survived.
> Could we run modern society on human power alone?
No, the current global population has swelled because of fossil fuel consumption. We can run pre-modern society on human power alone however.
> Unlike fossil fuels, human power can be a clean energy source, which produces little or no air pollution and soil contamination.
I hardly think a medieval alley with human waste pooling in it is clean.
> In combination with the right diet, human power is carbon neutral.
So not only do we have to be yoked to the Wheel of Pain, but we have to be vegetarians too?
> We can try and motivate people by making human energy production more fun, social, and exciting.
Let's gamify slavery!
> If students have to generate their own power, they are much less likely to waste it.
Now this I agree with. If only we could turn the same attention to student loans...