How difficult would it be to create a bike to reverse your electrical meter?

When you look at the hp/weight ratio it is highly in Lance's favor. Of course 1 horsepower is more of a comfortable work rate for a horse.

Remember, this is essentially a measure of how many calories we can consume and convert into useful work (while producing carbon dioxide.)

 

I recall as a youngster (some time ago now) riding a bike at the Chicago Museum of Science and Industry. I will grant that there have been improvements in all aspects of materials and power generation and generators and all that. But still...one could light one bulb with a fairly easy pedal, 2 bulbs for a very hard pedal, and 3 bulbs with a real burst of 'energy.' (No recollection of the wattage of the bulbs) It was a good and graphic representation of how little potential energy humans have!
Jim

 

It is not a matter of how much energy a person con generate, but more an issue of how wasteful much of our energy choices are. Lumen for Lumen, ~60 watts of conventional bulbs = ~15 watts of CFL bulbs =~1 watt of LED bulb, You could light the whole house with the bike if you used LEDs.

The reality is that riding a stationary bike isn't a very practical solution for RE, but it does give people a perspective on what energy "costs".

Icarus

 

What is your source for LED efficiency vs. CFL's? I've tried to look this up several times and every time I come away with the following: LED and CFL luminous efficacy are not that much different at the moment, about 30% and 20% respectively. Now if you need directional lighting the LED can do that much more effectively, but if you need general lighting, the CFL will probably end up more efficient.

 

"Living With Ed" is my new favorite show...DVR is set to record all. Just watched the "Mario Peebles & Bill Nye" show last night. Great show!

 

To be perfectly honest,,, I made it up! I know from experience that a 15 watt cfl comes close to the lumens of a 40-60 watt conventional bulb, depending on the bulb configuration.

As for the CFl led comparison. I have a 2 strings of led christmas lights strung together 120 led,, putting out about as much light as a 40 watt light bulb,, burning under one watt! The have been on since before christmas, 24/7 with a kill-a-watt meter, and they have used less than 1 kwh of electricity. So while I made the numbers up,,, there is some basis in experience.

I don't know a lot about led lighting,, but what I do know is that real advances have happened in the last couple of years and I expect that progress to continue.

On the bigger picture,, people need to realize that energy comes with a cost,, often a cost that we don't see environmentally, like the cost of coal fired electricity. As such we make choices, and one of those choices needs to understand the costs of those choices. If you have to walk to the store, you might think about how much energy it takes to bring the groceries home. If you have to hoe the garden, you might appreciate the energy involved in growing it. One of the consiquences of our energy intense culture is we have little or no connection to those costs. Riding a stationary bike to watch TV might be a good idea! (Not that I'm going to do it!)

Icarus

 

Darn, I was hoping you had something definitive. What you stated seems to be the common perception and what people expect. However, I've had trouble finding a good basis for it.

Like I said, from what I've read and seen, for directional uses, LED's really should be superior--probably several times over. (I suspect that is a big factor in why the common belief is that LED's are an order of magnitude more efficient. It's the app vs. an apples-to-apples comparison.) If one has a properly constructed multiple LED source I can see where many specific applications could be several times more efficient than a CFL. (Can lights and spots should be good LED applications in the near future...I've got several candidate fixtures in mind including one on a dimmer.) I've been using red light dimmer equipped LED's for astronomy for 13 years now and rarely change batteries even though I will read maps for hours at a time, night after night, so I know how efficient they can be.

In the general lighting sense, it is my understanding that LED's are only marginally more efficient at present. I'm seeing that in the wall plate mounted night light LED's. They save more juice than a CFL would (if I could get one that small) but they are marginal as far as illumination goes--as in they give off several times less effective light than the incandescents they replaced.

Long term I expect LED's to become increasingly better replacements, but I suspect it will be another decade before they muscle out CFL's in general applications.

 

That would make folks check the energy ratings on the TV's closer before purchase!

"Honey, come help me pedal so I can watch the football game on the big screen plasma!"

10 minutes later...

"Call 9-1-1..." <thump>

 

Shawn,

I think you are on to something about the different applications for LEDs vs CFLs. Clearly one has an advantage over another in different apps.

What too many people do is over light a room and under light a task. CFLs and conventional bulbs are very good at throwing light in 360 degree dispersion, while LEDs are much more directional. The reality is that people tend to use no directional bulbs for directional tasks. A low wattage intense work light is way more efficient than a general larger light,,, even if on a lumen to lumen basis the directional might be a bit less efficient if I am making myself clear.

If you really wish to be efficient, you would use bright LEDs for task lighting while with using Cfls for table and general room lighting. I have seen great advances in can lights leds in the last year, (cfls too)

What people need to do is be more aware of how they use lighting and reduce un-needed light. You can live quite well, with a well lit house using very few KWH's.

Icarus

 

There are plans to build your own pedal-powered (stationary bike) electric generator available online...

Search for
David Butcher: Pedal Powered Generator
(They don't allow me to post URLs here yet.)

Note unfortunately this design is not for grid-tied application (running a KwH meter in reverse.)

Nonetheless, I hope this helps.

 

POM rulz. he ain't no whinging pom.

What does Okra whiskey taste like I wonder?

 

It has to be better than eating okra as a vegetable. Have you ever seen cooked okra? It looks like someone sneezed on a plate.

Tom

 

Plain okra is disgusting. But okra is what makes gumbo what it is. Then the snotty consistency disappears and you have a fabulous soup.

Oh, and you don't get much electricity from human power. Maybe enough to light a low-power light bulb for half an hour.

And turning bicycle pedals is one of the most efficient ways to capture human power. That's why bicycles have endured as long as they have. Rowing can increase the power output, but you cannot keep it up for as long, so you get less energy over the long run.

A better bet is a PV panel. And a windmill. There are sustainable ways to produce energy. The real problem is that in our system of government, the people with the most money determine who makes the decisions. So entrenched interests prevail over good sense.

 

The 74 watts of power for a human seems more realistic for an average person than the 186 watts of power for an average human.
74 watts 1/10 hp means lifting 55 lbs one foot upward every second
186 watts means lifting 140 lbs one foot upward every second. It would take a pretty fit or very large athlete to keep that up for 30 minutes.A normal bike rider probably couldn't do that-a normal bike racer sure could.

I seem to remember that the Gossamer(sic) human powered airplane needed a pretty fit bike rider to produce around 1/2 hp for the trip across the English channel-I forget the particulars, but it took a fit -professional grade-bike racer to produce that sort of power for the hour or two the trip took.

The 75 watt rider would save 1-2 cents per hour-and he would burn maybe 700 calories per hour(KCals actually). This would take-fuel wise- about 1 quart of milk-$1 or 1/2 loaf of bread $1.25.If you wanted to eat sugar, you could cut the cost to maybe 30 cents(if sugar is 60 cents per lb-not sure of the price).

It would be fun-if you were doing the exercise anyway.
Charlie

 

That's because they didn't prepare it right. I prefer fried okra, but okra in gumbo or Brunswick stew is good too. My wife likes pickled okra.

 

I pretty sure it has something to do with The South, which is also related to grits and sweet tea. My Yankee senses are on high alert.

Tom