Anyone generate electricity w/ an indoor trainer?



jpr95

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Oct 11, 2010
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Okay, first off, I have a little-used CycleOps Wind (I think--bought it used, don't really care) trainer. It will likely remain little-used as I discovered pretty quickly that even with watching TV to try to distract myself, I can barely tolerate 45 minutes on the infernal contraption as it is just mind-numbingly boring. That, and there's no coasting, which just feels weird to me.

However, I kind of like to dabble in off-the-grid ideas and gizmos, so I was wondering if anyone here had done something like hook an automotive alternator to their trainer to generate some electricity or charge a battery of some sort to power some household item. In a way, it might get me more interested in using the trainer in the cold and snowy months if it presents some sort of technical challenge in the creation/fabrication (and perhaps the cheap acquisition of parts), then a physical challenge in its use.

Any experience (or vicarious knowledge)?
 

limerickman

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Jan 5, 2004
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"After doing a little research, I found that an efficient bike generator pedaled by a reasonably fit person can produce about 100 watts of continuous output. An experienced biker can produce a peak of more than 400 watts, but peaks don’t count for much when it comes to pedal power generators. Assuming an ambitious exercise period of one hour, a person could produce about 100 watt-hours of electricity. That is one-tenth of a kilowatt-hour (1 kilowatt-hour = 1,000 watts for 1 hour).

Most of us pay our local utilities about 10 cents per kilowatt-hour for electricity, including taxes and surcharges. By getting our heart rate up and breaking a sweat for an hour, we could produce 1 cent worth of electricity. Not much incentive, I thought.
With the electricity produced by an hour of pedaling, we could light a 100-watt incandescent bulb for an hour, or power a 20-watt compact fluorescent bulb for about five hours"


Read more: http://www.motherearthnews.com/Renewable-Energy/2008-10-01/Pedal-Powered-Generators.aspx#ixzz1YFsM4Gr1
 

limerickman

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Jan 5, 2004
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Storing generated electricity seems to be a major stumbling apart from being unable to generate sufficient electricity to power household appliances.
 

alienator

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Jun 10, 2004
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What's an indoor trainer?

By riding outside every day, I become better acclimated to our local climate and thus do not need the air conditioner set so low (desert southwest), and I therefore use less electricity. Conservation by better conditioning.
 

AlanG

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Dec 26, 2010
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Ed Begley Jr. rides a bike on his TV show to store power in batteries that are also used to store energy from his solar array. He says that 15 minutes of hard riding stores enough energy to make 2 slices of toast. His setup is a trainer that runs a generator. Recently I saw a Peace Corps demonstration of bicycles that used small generators to charge cell phones. These were like the typical generators used to run headlights. And they had a mechanical contraption that attached to a bike that let it thresh corn.



The one I saw just used a regular bike on a stand with this thing attached to it somehow.

While we are all in favor of exercising for health, if you look at this from an ecological viewpoint... it might be better to be a couch potato. (As long as we eat the minimum amount of food to sustain us.) The amount of resources to produce enough food for us to generate a kilowatt of energy is pretty substantial compared to getting energy directly from the sun, wind, water, or even fossil fuel.
 

tafi

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Jul 31, 2003
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While we are all in favor of exercising for health, if you look at this from an ecological viewpoint... it might be better to be a couch potato.
I think this might be a bit simplistic,

Being healthy is not just a selfish pursuit. Fit people put less strain on health systems; ride/walk/run rather than drive their cars; are out exercising rather than wasting time in front of a power hungry plasma TV; are more aware of their diet and (we hope) eat less processed, energy intensive foods; tend to have a better appreciation for nature (becasue they are out in it more often); are more socially active in their communities; and are able to have longer and more fulfilled working lives than the average couch potato.

That would seem well worth the investment of a few extra kilojoules of pasta per day if you ask me..... mmmm pasta.

PS: It takes a lot more energy to move a 1.5 tonne car with driver than it does to move a rider on 10kg bike. Driving a car 100km also requires about 7.4kg of fuel (based on 10km/l or about 24mpg and the average density of petrol) this has to be refined and transported, which costs a lot more energy and resources than growing the same amount of food. Even if you cycled 100km per day, I doubt you could eat 7.4kg of food per day, therefore the transportation cost for the required food is smaller too. Of course we will never be able to talk in dollar terms here because we all live in different countries with different oil pricing structures (some of us get subsidised fuel and others of us pay tax when we buy fuel).
 
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An old Guy

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Feb 12, 2011
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Ambitious bicyclists can produce 200w for an hour maybe even 5 hours.

But I found out when I was young that the cost of riding a bicycle is a bit more than the cost of driving a car - just the fuel cost.

I suppose that I will buy my electricity as it is cheaper than I can produce it.
 

alienator

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The cost of purchasing and operating a bike is much less than operating a car.
 

jpr95

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Originally Posted by alienator .

The cost of purchasing and operating a bike is much less than operating a car.

...if you neglect to factor in the value of your time. I suspect at today's fuel prices, the straight-up fuel cost comparison is a wash. I know I eat a bunch more when I cycle, and my most efficient vehicle only gets about 16 and 24 mpg town and highway respectively. If I bike 24 miles, (saving $3.50 in gas), I would probably eat and drink that much extra over the course of the subsequent 2-3 days.

BUT, I don't replace driving with cycling, it's a hobby/recreation/fitness thing for me. I was mainly thinking about potential emergency, off-the grid things.
 

An old Guy

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Originally Posted by alienator .

The cost of purchasing and operating a bike is much less than operating a car.
Those are sunk costs. The incremental cost of a single trip is only the cost of fuel. Food costs about the same as gasoline.

The cost of my time (I bill out about $100/hr) makes the cost of bicycling much higher than the cost of driving. Even if one considers the cost of the purchase and other costs. If we consider the $.50/mile allowance for driving, driving is more favorable.
 

alienator

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Originally Posted by An old Guy .




Those are sunk costs. The incremental cost of a single trip is only the cost of fuel. Food costs about the same as gasoline.

The cost of my time (I bill out about $100/hr) makes the cost of bicycling much higher than the cost of driving. Even if one considers the cost of the purchase and other costs. If we consider the $.50/mile allowance for driving, driving is more favorable.


Then obviously those must the only costs and the sunk costs don't count. Clearly objective analysis must show that driving car--excepting what naysayers call the "real costs" but are are really fake costs since they're sunk costs and don't matter once they're sunk since obviously not all spending comes out of a family's budget or anything like that--is cheaper than riding a bike. Obviously. I'm surprised that investigative journalists haven't uncovered this data. I'll bet there's even a mathematical relationship that goes like this:

Sunk Costs = Costs - Re{Costs} and Re{Costs} ≧ Sunk Costs (the funny little symbol in the last part of the Operational Cost Function of a Bike is a math thing that means "always greater than".

It's well known that eating food is something that only cyclists do and that drivers never eat.......so eating costs for a driver need not factor such silly things. I envy you that you don't have to eat, what with the car making eating irrelevant.
 

AlanG

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Dec 26, 2010
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Originally Posted by An old Guy .


Those are sunk costs. The incremental cost of a single trip is only the cost of fuel. Food costs about the same as gasoline.

The cost of my time (I bill out about $100/hr) makes the cost of bicycling much higher than the cost of driving. Even if one considers the cost of the purchase and other costs. If we consider the $.50/mile allowance for driving, driving is more favorable.
You know I was pretty much joking about the food thing. As for cost, if you consider a bike as a mode of transportation, it is performing double duty by providing fitness too. This could end up saving you time if you otherwise would go to a gym or do some other activity for fitness. The cost of using a car also includes insurance and maintenance which are continuous costs. The "sunk" costs which we call fixed costs over here are typically depreciated over time and and can be calculated as part of the cost per mile to use a vehicle if you care to do so. A simple example would be a leased car that costs $18,000 for 30,000 miles of use for 3 years. At 25 mpg and a cost of $3.50 per gallon that adds up to another $4500 for fuel. If we assume oil changes and other maintenance is included with the lease, but add $1,000 for insurance, we get a cost of $23,500 to go 30,000 miles. That works out to $7833 per year or about $.78 per mile. I don't know how you work out the cost of riding a bike 30,000 miles to include the cost of food. But when it comes to getting a lot of work done cheaply, it is hard to beat a machine burning gasoline compared to human power.