Alternative Energy Forums

Hello.

I recently had an idea. I wanted to find out if anyone has information about large-scale human-based power.

I got the idea from watching a movie that had some shots of power-generating windmills, lots of them. If kinetic energy from wind can be converted into electricity in your home, why can't the combined power of thousands of people be used in the same way?

I had the notion that a person operating a bicycle would not be enough. But imagine an entire legion of people, all pedaling bicycles attached to generators at the same time for hours at a time. That's an energy AND unemployment solution. It seems like that would be pretty economical, but I wanted to find out what someone else thinks. It occurred to me that someone else surely must have thought of this by now and it wasn't done because it couldn't be. But, you never know unless you ask.

kleinicus

Kleinicus,

There are already legions of humans generating energy in concentrated areas that could be harnessed for useful work. Health Clubs. Unfortunately club operators haven't (yet as far as I know) seen this as an opportunity. Instead they run air conditioners and vent fans to draw off the heat - instead of capturing the energy and using it to run the building. Seems like a great business opportunity though.

Nick Hein
Morgantown, WV

I’m replying to the first post, kleinicus, I think that this idea is stupid- as if people have time to waste in order to generate energy. This is so stupid for a lot of people to be pedaling bicycles, attached to generators, Isn’t there a smarter way to produce energy than having to waste people’s time…even though you said that this would help the unemployment situation. Who has the money to spend to pay those people? This reply is not meant to be negative…you asked our thoughts, so I’m giving you mine.

AE LISA

The problem with this idea is that the energy needs to be wasted energy. If I expend 1000 Calories for the sole purpose of creating electricity then I will have to consume an additional 1000 Calories of food. A lot of energy goes into producing food; I’ve seen some statements that it is a 9:1 ratio of energy input to the caloric value of the food (regardless if this is an overestimate, it definitely not 1:1). If the energy is otherwise wasted, say if I wanted to go for a bike ride, then it could be possible (then again, you could argue that simply biking to work and for errands is a better option). Fitness centers could use this. However, the actual energy captured is not significant - typically around 200 W or less per person. The cost of and required energy to manufacture the equipment isn’t typically worth the return.

Yeti

AE LISA said: "Isn’t there a smarter way to produce energy than having to waste people’s time... even though you said that this would help the unemployment situation. Who has the money to spend to pay those people?"

Again, I’m not being negative, but I’d like to try to answer your question.

The US Government pays out billions annually for welfare. Some recipients can’t work. Some can, and want to. Some won’t. So, why not create "gym-like" areas and produce power on a larger scale and offer a good wage? You also have many people that might enjoy making a profit on their gym visits, even if it’s just a small one.

Chuck

Paying people to produce energy is just not something that will work, even if it is for welfare or to create jobs. A single person generating 150W for 8 hours straight (which is not something most people can do) will produce 1.2 kW-hr, or about 10 cents worth of electricity. That person also used over 1000 Calories. The whole process is net energy and money negative unless it is waste energy.

Yeti

Why not have it a tax write-off or discount.

Yakas

Hello Kleinicus.

I like your thinking, however, a non energetic green power supply can be achieved by having a Mcdonald's and then converting the resultant methane gas to electricity.

Those who can't afford to eat out still equally contribute their bit.

Peter

I had this very same idea, well almost. Nuclear power plants and coal power plants that we all rely on today both create steam through heat which powers turbines and generates electricity. These turbines are large, hence the massive power created.

Why can’t we build a massive rotating structure, with a thousand "push" bars around the entire circumference. People would be paid to push. Through the use of gears and other mechanical things that I’m not familiar with, a giant turbine would be turned, generating as much or more than a nuclear or coal plant, depending on how big you decided to build it.

Or, save the wages and make prisoners push. The giant structure would be part of the prison.

and oh,

AE LISA said: "Isn’t there a smarter way to produce energy than having to waste people’s time... even though you said that this would help the unemployment situation. Who has the money to spend to pay those people?"

WTF? Who has the money? The power plant would have the money. Who has the money that employs all of the guys working at the nuclear power plants?

TMoney

Hi Kleinicus,

I had the same idea but when I was in secondary school and then I decided to do some research to find out advantages and disadvantages of it.

My conclusion was;
It is morally in-correct, It is so negative, It will make Human a machine (think about a person paddling for 8 hours and it will not be alone; at least thousands of them!) This process has to be continuous to get sufficient amount of electricity. It will also create 2 classes in society, one who works (like a machine) to generate electricity and the other who consume that. And that’s the worst thing you want to do.

Economically: It will get job to everyone who wants to work but not enough salary (Consider national minimum wage per person per hour £5 in UK for example for 1000 people its £5000/hr that generates hardly 30kWh that is done for £30 by electricity company) and poor living condition cause they will not have time to enjoy their life!

Dis-advantages:
1. Morally incorrect
2. Economically not viable
3. Socially disruptive

Advantage:
1. Clean/green energy
2. Job for everyone who wants to work like a machine!

bhags

Phi,

1/12 HP might be right. I saw a program on the Discovery Channel, or some such educational channel, where they were discussing this. They said a competitive cyclist such as Lance Armstrong generates about 1/4 HP. (I think I’m remembering correctly)

U.S. Engineer

I just registered and would like to "contribute" to this forum. The idea isn't stupid, just unfeasible. We are weak machines. Thinking "outside the box" like this is just what we need.

TMoney said 2 silly things.
Firstly, don't think of the prison population as an untapped resource, just the opposite. The potential for injury would cause for costs 100 times more than the energy production. A worn knee in 2002 cost me $13,000, thats a lot of wattage, even in the most expensive areas.

Prisoners cannot be forced to work under the Constitution. If we make prisons profitable, or even self sufficient, we give the govt incentive to "enslave" as many people as possible. Do you want a tax audit every year? How about mandatory minimum sentences for traffic violations? We need imprisoning our citizens to be expensive to give society incentive to rehabilitate (potential) wrongdoers rather than simply punish them and their families again and again. Americans are all about vindication, but they want their vengeance to be severe, quick and cheap. It's supposed to be 50/50 punishment/rehab. Not a popular concept, but it's a human nature thing. Nobody would be for capital punishment if they thought we could get a few "kill"-a watts out of a convict rather than putting a few into him.

Secondly, it's obvious that human powered generators couldn't produce enough equity to pay for the food required, let alone a small wage. If this were feasible we'd use the 60,000 wild mustangs that the Dept of Interior is wondering what to do with. Horses are (12x) stronger, cheaper to feed and don't sue the boss.

The energy companies now make millions to pay thousands of employees. With human-power they would make thousands to pay millions of employees.

Chuck, the welfare recipients would get hurt and sue the govt for millions, each. Most are on welfare for a reason.

bhags makes very good points, IMO.

Advantages: Literally none

Let's look at the simple math of "human power". All power generated by living beings comes from the hydrolysis of ATP, a process which generates 31.1kJoules/mol of ATP. ATP is produced by cellular respiration from glucose. 38 mol of ATP is produced along with 6 mol of CO2. So that leaves us with:

1 kW = 1 kJ/s
1 kW*hr = 3600 kJ
3600 kJ/ 31.1kJ = 115.76 mol ATP cleaved to produce 1 kW*hr
115.76 mol ATP * 6/38 = 18.28 mol CO2 produced

18.28 mol CO2 * 44 g/mol CO2 = 804.32 g CO2 produced = 1.77 lb CO2/kW*hr

This is compared to the estimate from http://www.carbonify.com (given the source it is probably over-estimated) of 1.5 lb CO2/kW*hr. This is also assuming a 100% efficient system where all the energy from the ATP is converted properly to muscle movement and then electricity which is of course not true in the slightest. Add in those inefficiencies and that number goes up dramatically.

So Human power is not as environmentally friendly as our current sources that is if we're only talking CO2 here. Since CO2 emissions have been simplified into being the root cause for all climate change problems then that's how we'll talk.

Now let's talk economically.

1 joule = 0.239005736 calories
3.6 Mj/kW*hr = 860420.64 calories/kW*hr

Pretty much the cheapest calorie source is something like Canola oil at 7 cents / 200 calories.

860420.64 cal/kW*hr * $0.07/200 cal = $301.15 / kW*hr

That compared to current energy costs of 11 cents / kW*hr. These estimates also don't include considerations for a balanced nutritional intake necessary to sustain physical activity which would surely cost more than a canola oil diet.

So it's not economical either.

UNLESS the work is being done anyways. This is assuming that we are increasing human power output worldwide to generate power. All of this math involving cost and emission goes out the window if you were planning to work out anyways. Change your workout to spin a generator instead of a bike and you've not increased your carbon output or cost by anymore than you were going to anyways. Then again... if you care about the environment should you even be working out in the first place? Your "footprint" will be bigger than someone who sits at home and reads. Of course, I'm kidding.

Bottom Line: The energy crisis a multi-faceted problem and people need to learn to look at all of the hidden costs. If anything, it is more about the using of energy and the demand for all of this energy and reducing that than it is about the production of cleaner energy. All ways of producing energy have some sort of CO2 footprint. Certainly there are more and less efficient ways and investigating them is a great idea economically, politically and ecologically, but until we curb our need for energy we will ALWAYS have much higher CO2 emissions than our ancestors.

As for human power, it's about working smarter. If you were going to do a physical activity anyway? Find a way to convert some of your energy into electrical energy. Instead of spinning a fan for a resistance work-out, spin a generator. But if you thought it would be good to power your house with your bicycle, in order to actually succeed at generating the same amount of energy as a power plant you would emit more CO2 and spend more money. That would make you a poor polluter.

MathFTW

I apologize my cost calculations were wrong since I forgot that human dietary units are referred to as "calories" but are in fact kilo-calories. I will admit that the cost aspect of it surprised me and now that I remember this it puts it into a much more reasonable amount:

860.42064 kcal/kW*hr * $0.07/200 kcal = $0.301 / kW*hr

Still more expensive but more in line with what I thought it would actually cost.

MathFTW

Sure, watch the first episode of Conan the Barbarian.

ragnarviking