View Full Version : Using a Bike to Generate Electricity
Hey, does anyone have any information about using bicycles to generate electricity? Specifically, I'd like to take a regular bike and use it to charge a battery that I can then use to run electric appliances. I don't want to make permanent modifications to the bike. My web searches have turned up surprising little about topic. But I know it's been done. Any websites, books or other info you have is much appreciated.
Thanks all
With a dynohub you can ride about 65 miles and charge up 4 AA size NiMH batteries. Does that give you the amount of electricity you want?
Eli_Damon
02-02-08, 07:28 AM
I know of only one commercial solution, which I came across last night. The Busch & Mueller "Ixon" or "Ixon IQ" headlight with the "Ride & Charge" accessory, along with a bicycle dynamo, can be used to charge a group of four AA batteries. Look for "Ride & Charge" on "http://peterwhitecycles.com/b&m.asp".
I know of only one commercial solution, which I came across last night. The Busch & Mueller "Ixon" or "Ixon IQ" headlight with the "Ride & Charge" accessory, along with a bicycle dynamo, can be used to charge a group of four AA batteries. Look for "Ride & Charge" on "http://peterwhitecycles.com/b&m.asp".
Looks like a nice product. Their instructions say that you get a full charge for 4 AA NiMH batteries after five hours of "brisk" riding. Elsewhere it mentions a speed of 20 km/h. Five hours at 20 km/h is a metric century (62 miles).
I'd like something that offers more diversity, i.e. running stuff from television to toasters. I'd also like to build it myself.
Cheers
wahoonc
02-02-08, 08:10 AM
I'd like something that offers more diversity, i.e. running stuff from television to toasters. I'd also like to build it myself.
Cheers
First thing I would do is some basic research on how much energy a television or toaster actually sucks down. Then look at how much riding it would take to actually generate that amount of electricity. It is not as simple as it looks at first....TANSFL....a good rider can generate 400 watts;) I know for a fact my toaster will not run on a 1000watt generator:p
Aaron:)
Good point. I remember seeing years ago a "bicycle powered" television. The television actually ran on a car battery that was charged using a bicycle.
From newpointenergy.com (sorry no toaster)
Air conditioner: 2,000 to 5,000 watts / hour
Refrigerator: 60 watts / hour (or 1500 watts / day)
Washing machine: 500 watts / hour
Clothes dryer: 4,000 watts / hour
Dishwasher: 1,200 to 1,500 watts / hour
Microwave: 600 to 1,500 watts / hour
Television: 150 watts / hour
Personal computer: 80 to 150 watts / hour
In searching for the above, I found this http://www.econvergence.net/electro.htm
It looks like a stationary stand with a generator attached. Sells for $400.
I found a bunch of sources that discuss watts per hour a non-athlete can generate on a bike. They fall between 50 to 225 watts per hour.
Oh yeah, and I found one site that estimated 10 hours to trickle charge a car battery at ~ 100 watts.
If it takes 10 hours at 100 watts to charge a car battery, does that mean that a car battery can hold 1,000 watts?
twobikes
02-02-08, 09:47 AM
In order to power normal 120 volt AC appliances you will need a voltage inverter that changes 12 volt DC current to 120 volt AC current. These are available widely, even at places like Radio Shack and Wal-Mart. A 400 watt unit is probably about $30 these days. But, 400 watts does not do much if a heating element or a motor is involved. If you are powering something like a radio or a small television, 400 watts can work. I have a 400 watt inverter I use to power my laptop if I need to use it while riding in a car. 400 watts is just enough for the power supply my laptop uses.
You will also need a 12 volt automobile battery. Virtually any bicycle generator capable of 12 volts will work, but charging the 12 volt car battery will be a bit slow and require a lot of pedalling between periods of usage. Most bicycle generators are AC. You will need to add at least one diode capable of handling the generator's output. The half of a sine wave graph of the output will be a bit choppy, but I also read that is a desirable situation when charging a battery is the goal.
Each device you need to add to the chain is less than 100 percent efficient. Each device has its own initial cost and has a useful life after which it needs repair or replacement. After a while the objective you have stated becomes an interesting exercise in theory, but is not very practical.
I once thought I would like to power a small television from an alternator connected to my bike. The object would be to make me pedal a certain amount. I would know the TV program goes off unless I keep pedalling.
crhilton
02-02-08, 10:14 AM
From newpointenergy.com (sorry no toaster)
Air conditioner: 2,000 to 5,000 watts / hour
Refrigerator: 60 watts / hour (or 1500 watts / day)
Washing machine: 500 watts / hour
Clothes dryer: 4,000 watts / hour
Dishwasher: 1,200 to 1,500 watts / hour
Microwave: 600 to 1,500 watts / hour
Television: 150 watts / hour
Personal computer: 80 to 150 watts / hour
In searching for the above, I found this http://www.econvergence.net/electro.htm
It looks like a stationary stand with a generator attached. Sells for $400.
I found a bunch of sources that discuss watts per hour a non-athlete can generate on a bike. They fall between 50 to 225 watts per hour.
Oh yeah, and I found one site that estimated 10 hours to trickle charge a car battery at ~ 100 watts.
I think a modern LCD tv beats that 150watts by a landslide. I bet a normal (less than 35") LCD TV consumes under 100 watts; but what do I know maybe the backlight is just that crazy bright.
A PC is now more like 40-600 watts depending on so many factors it would take me a day to explain. Let's just say anyone could power a laptop while they use it, although if they want hard processing and they're not a cyclist they'll be sweating.
crhilton
02-02-08, 10:17 AM
I'd like to point out that cycling to power home appliances is not a good ecological solution. Mammals are not an efficient machine to process energy from food. It'd be preferable to grow a few select crops and use chemical processes to extract energy from them (right now we do this with ethanol). The equipment for that is probably far out of your reach.
If you're just doing this for giggles then more power to you! Seriously, you're going to need it to power anything more than your TV.
If it takes 10 hours at 100 watts to charge a car battery, does that mean that a car battery can hold 1,000 watts?
You can charge a lead acid battery slowly for 10 hours and then take it out all in one hour, if that's what you're asking. You lose about 1/3 of the energy in the charge / discharge cycle.
I'd like to point out that cycling to power home appliances is not a good ecological solution. Mammals are not an efficient machine to process energy from food. It'd be preferable to grow a few select crops and use chemical processes to extract energy from them (right now we do this with ethanol). The equipment for that is probably far out of your reach.
If you're just doing this for giggles then more power to you! Seriously, you're going to need it to power anything more than your TV.
In an off grid situation you should put your first efforts into reducing your energy requirements. For example, lighting - fluorescent is better than incandescent, but you might get by with LED's, and by the way do you need the extra light at all if you can use the dark for sleeping. Eliminate energy conversion inefficiencies when possible, for example using a treadle lathe or a hand drill instead of the motorized versions. Look into alternatives, like boxed crackers instead of freshly made toast. Note - I'm not recommending low energy living in general, just saying that if you don't have easy access to cheap energy you have to do a lot of things differently.
If it takes 10 hours at 100 watts to charge a car battery, does that mean that a car battery can hold 1,000 watts?
No, watts is the wrong term for stored energy (such as in a battery). Watt hours is the appropriate term.
I have a battery with claimed energy storage of 240 watt hours. You can use this energy in 24 hours at a rate of 10 watts or in 1 hour at a rate of 240 watts.
A battery that charges using 100 watts for 10 hours would have to store 1000 watt hours if it were 100% efficient.
Stored energy, think "watt hours". How fast something uses up energy, think "watts".
Regarding the power used by TVs, here is a page of interest:
http://reviews.cnet.com/4520-6475_7-6400401-3.html?tag=nav
screen sizes 27 inches and larger, HDTVs, the one using the least power was 106 watts while typical LCD sets were closer to 150 to 200 watts... and some large LCD and plasma sets used 400 to 600 watts.
It would probably be better to use the pedal-generated power to directly do mechanical work, like grinding grain or running a saw. Charge your batteries with solar, wind or hydro.
TRaffic Jammer
02-04-08, 12:55 PM
So I guess my sketches for Dr Evil-esque bike powered LASER weapons are out then.
So I guess my sketches for Dr Evil-esque bike powered LASER weapons are out then.
I'd focus on making a good cheap blinky first!
TRaffic Jammer
02-04-08, 01:04 PM
Curses....
Saw on the superbowl brodcast where cyclists produced enough power for 1/2 hour of the pregame show.
http://digg.com/general_sciences/Using_human_energy_to_power_the_Superbowl_Pre_Game_Show
http://www.humanenergy.ampenergy.com/
Cyclaholic
02-04-08, 05:45 PM
So I guess my sketches for Dr Evil-esque bike powered LASER weapons are out then.
http://i187.photobucket.com/albums/x248/cyclaholic_album/dr-evil.jpg
You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads! Now evidently my cycloptic colleague informs me that that cannot be done. Ah, would you remind me what I pay you people for, honestly? Throw me a bone here! What do we have?
http://www.econvergence.net/electro.htm
This is the Pedal-a-Watt - I think the same one used at the Super Bowl pre-game show.
Here's the problem with pedaling a bike instead of plugging an appliance into the wall:
Let's say you pay $0.25 per kilowatt-hour and can generate 100 watts continuously while sitting on your bike inside the house. In 10 hours, you will save $0.25. Of course, you are unlikely to sit and pedal for 10 hours at one stretch, so it may take you a few days to save that $0.25.
Now, while you are sitting in the house cranking away, you're going to get pretty warm because there's not much air flow. So, you can turn on a fan to help cool you down. But the fan takes energy which eats into the output that is charging a battery, running the TeeVee, etc.
So, if your idea is to save money, then you would be better off getting a second job. It will pay a lot better and probably take less effort. If you think you're saving the environment, you might think again. There are probably more productive ways to do it then by cranking a generator by human power.
For what it does, electricity is very, very cheap.
Air conditioner: 2,000 to 5,000 watts / hour
Refrigerator: 60 watts / hour (or 1500 watts / day)
Washing machine: 500 watts / hour
Clothes dryer: 4,000 watts / hour
Dishwasher: 1,200 to 1,500 watts / hour
Microwave: 600 to 1,500 watts / hour
Television: 150 watts / hour
Personal computer: 80 to 150 watts / hour
I do not understand these figures. Average power per unit time? How does the refrigerator make sense?
Electricity just confuses the dickens out of me.
The original idea was that it would be a fun project. An opportunity to learn something. Saving money? No. My electricity bill is under $50 in the dead of winter. The practical goal, I suppose, was to have emergency power when our electricity goes off as it does around here sometimes. Not to power the fridge or big appliances, but to power the radio or laptop. Even better a small electric heater; sounds like that'd use too much power though.
You all have pretty much convinced me that it's impractical even for that. Though I'm still interested in references on the subject if anyone knows of such.
Cheers all.
The original idea was that it would be a fun project. An opportunity to learn something. Saving money? No. My electricity bill is under $50 in the dead of winter. The practical goal, I suppose, was to have emergency power when our electricity goes off as it does around here sometimes. Not to power the fridge or big appliances, but to power the radio or laptop. Even better a small electric heater; sounds like that'd use too much power though.
You all have pretty much convinced me that it's impractical even for that. Though I'm still interested in references on the subject if anyone knows of such.
Cheers all.
A small battery powered radio should do fine for almost any loss of electricity. You can buy a wind up radio from here (http://www.ccrane.com/radios/wind-up-emergency-radios/freeplay-plus-radio.aspx) that eliminates the need for batteries. For the laptop, the simple solution is to get a large deep discharge marine battery and trickle charger. connect the battery to an inverter and plug in the laptop. Should keep the laptop running for many hours.
And, if you simply pedal your bike in any trainer, you won't need a heater!
twobikes
02-08-08, 07:51 AM
A local science display features a stationary bike. You sit down and begin to pedal. Somehow in the process an electric light bulb begins to illuminate as you reach a threshhold level. Suddenly the relatively easy pedaling becomes much more difficult. I doubt that one person on a bicycle could power a small electric heater. You could power a light bulb and let its light be absorbed by sheet aluminum painted black to make heat that the aluminum would radiate into the surrounding area. Even then, more heat is likely to be produced by increased body heat from the exertion of pedaling. Other than the initial cost of a solar cell panel, you could use daylight to charge a 12 volt car battery and power a laptop by means of an inverter combined with the laptop's power supply. That would probably work better than pedaling to charge the battery, and small solar panels for that purpose are available. I am sorry that I cannot give you any information sources.
No. My electricity bill is under $50 in the dead of winter.
If you spent all of your waking hours for a month pedaling a bicycle to create electricity (and did your best to produce a lot of power) you would not produce anything approaching $50 worth of electricity.
I think it's fair to estimate that if you do it for a long time, you can probably produce no more than 200 watts of electricity after efficiency losses. After ten hours you will have produced something like 2 kilowatt hours. Right now in North America, 2 kilowatt hours of electricity costs about $0.20 to $0.35 US.
Spend your whole month at it and you might have $10 worth of electricity. Incidentally, that's about half of a month's electric bill in my household of 2.
The practical goal, I suppose, was to have emergency power when our electricity goes off as it does around here sometimes. Not to power the fridge or big appliances, but to power the radio or laptop. Even better a small electric heater; sounds like that'd use too much power though.
I too have always wanted to build / have such a unit. I remember seeing one guys design on his wbsite. Seems the chain was connected to the front wheel, and the wheel itself much heavier than a normal bike wheel. The mass helped overcome the resistance of the thingy that actually created the electricity. Seemed to get the best results of the 10 different designs I had seen online.
Even better a small electric heater; sounds like that'd use too much power though.
For a certain amount of effort an electric heater will produce exactly the same amount of heat as a friction system (such as your standard indoor trainer).
What a great and crazy idea to use human power to generate electricity for daily use. Of course, the idea is over 100 years old.
Keep in mind that every time you convert power, you lose. So from bike to battery to appliance, you convert mechanical power to electrical to chemical to electrical to thermal, etc. Of course, that simple chain skips the whole human kinetic mystery of power generation that converts the pizza you eat into body motion and sets the whole process forward.
Your best bet would be to go direct from bike/generator to appliance. Keep your experiment simple and cheap. Bring your bicycle into your living room and use the 6 watt generator light to produce the lumens for your family to read and do homework. As for the toast, your best bet will be to put a slice of toast on top of your head as you pedal to create light for the family; multi-tasking and energy conservation at it's finest.
30 minutes of that experiment should be enough for you to understand the amount of energy it takes to use the simple appliances we take for granted.
The practical goal, I suppose, was to have emergency power when our electricity goes off as it does around here sometimes. Not to power the fridge or big appliances, but to power the radio or laptop. Even better a small electric heater; sounds like that'd use too much power though.
A bicycle is very efficient for generating heat (as opposed to electricity). I stay warm in wind chills well under minus 20 F.... As long as I keep pedaling!
From newpointenergy.com (sorry no toaster)
Air conditioner: 2,000 to 5,000 watts / hour
Refrigerator: 60 watts / hour (or 1500 watts / day)
Washing machine: 500 watts / hour
Clothes dryer: 4,000 watts / hour
Dishwasher: 1,200 to 1,500 watts / hour
Microwave: 600 to 1,500 watts / hour
Television: 150 watts / hour.
newpointenergy is confused. There's no such thing as watts/hour.
newpointenergy is confused. There's no such thing as watts/hour.
true. their figures are approximately correct if you leave off the "/hour" part and just call it watts.
(and running a fridge is probably around 1500 watt hours / day).
Another way that newpointenergy got themselves confused was that some of their figures are peak-usage and some are average-usage-over-time.
A typical microwave uses around 1000 watts while it is on but if you measure its typical usage in watt hours, (total energy used) it might be (1000 watts * two minutes) = 33 watt hours.
Peak usage for a microwage or toaster is very high (which makes them highly impractical as human-powered devices) but they typically use less energy in a day than a television that is watched for an hour.
Some other items' electricity use:
electric stove (per burner): up to about 1500 watts
electric oven: up to about 2500 watts
high efficiency lightbulb: about 30 watts
water-heat for a shower, typical: 1000 watts or more (electricity, equivalent amount of fuel)
computer: similar to television
toaster: similar to microwave
merlinextraligh
02-12-08, 01:14 PM
From newpointenergy.com (sorry no toaster)
Air conditioner: 2,000 to 5,000 watts / hour
Refrigerator: 60 watts / hour (or 1500 watts / day)
Washing machine: 500 watts / hour
Clothes dryer: 4,000 watts / hour
Dishwasher: 1,200 to 1,500 watts / hour
Microwave: 600 to 1,500 watts / hour
Television: 150 watts / hour
Personal computer: 80 to 150 watts / hour
In searching for the above, I found this http://www.econvergence.net/electro.htm
It looks like a stationary stand with a generator attached. Sells for $400.
I found a bunch of sources that discuss watts per hour a non-athlete can generate on a bike. They fall between 50 to 225 watts per hour.
Oh yeah, and I found one site that estimated 10 hours to trickle charge a car battery at ~ 100 watts.
If you've ever ridden with a power meter, it's quickly apparent how impractical the idea is.
I'm a pretty big guy,and race CAT IV. No great shakes, but my absolute power numbers (not as a function of my weight) aren't bad. I can sustain 300 watts an hour going absolutely full out.
So, even setting aside efficiency issues, I could watch TV, with a light on, for an hour. But after the first hour I'm SOL.
If you've ever ridden with a power meter, it's quickly apparent how impractical the idea is.
I'm a pretty big guy,and race CAT IV. No great shakes, but my absolute power numbers (not as a function of my weight) aren't bad. I can sustain 300 watts an hour going absolutely full out.
So, even setting aside efficiency issues, I could watch TV, with a light on, for an hour. But after the first hour I'm SOL.
You'll also need to eat 1000+ calories of food afterward. That dimes worth of electricity is getting expensive.
Regardless of the cost/benefit analyses found in this thread, pedaling for power seems like a good idea if you're going to be pedaling for exercise with your bike mounted on a trainer stand anyway. Why not charge up your laptop, iPod or cell phone at the same time? So what if you're not saving money?
Regardless of the cost/benefit analyses found in this thread, pedaling for power seems like a good idea if you're going to be pedaling for exercise with your bike mounted on a trainer stand anyway. Why not charge up your laptop, iPod or cell phone at the same time? So what if you're not saving money?
I guess if somebody gives you the generating equipment for free it might be a good idea. but, at $0.10/hr worth of electricity, it would take a lot of pedaling to pay for a generator.
Regardless of the cost/benefit analyses found in this thread, pedaling for power seems like a good idea if you're going to be pedaling for exercise with your bike mounted on a trainer stand anyway. Why not charge up your laptop, iPod or cell phone at the same time? So what if you're not saving money?
Pedalling indoors for exercise is wasteful anyway. If you're living car free, get on your outdoor bike or strap on your snowshoes and go do a usefull errand when you want exercise :)
toThinkistoBe
02-25-08, 09:21 AM
What if all the stationary bikes in a gym were setup to generate electricity? I imagine a whole room of bikes would be able to generate a substantial amount of power.
What if all the stationary bikes in a gym were setup to generate electricity? I imagine a whole room of bikes would be able to generate a substantial amount of power.
If people are going to waste time and energy on indoor exercise, I suppose it kind of makes sense to try to harness that energy. At least it makes sense in winter: you could simply simply turn the gym's furnace down slightly and let the body heat and mechanical friction generated by pedalling help heat the building. That way the calories burned off are somewhat recaptured and used.
However in summer, in a warm climate, the energy generated by indoor exercise is doubly wasted, since you not only generate excess heat from pedalling that can't be captured: but you also consume additional energy turning up the the air conditioner to compensate for that. If people want the energy generated by exercise to be recaptured and used, it would be better they exercise outdoors, doing something usefull like riding to the grocery store or delivering packages for Fedex by bike.
What if all the stationary bikes in a gym were setup to generate electricity? I imagine a whole room of bikes would be able to generate a substantial amount of power.
Assuming an average of 100 watts per bike, for every 10 bikes in use, you would get one kilowatt-hour of energy every hour. That's worth $0.25. Each bike would generate electricity worth $0.025 per hour of use.
Assuming that the generator and electrical interface equipment added $100 to the cost of the exercise bike (probably on the low side), it would take 4000 hours of use to break even. Not a very good return on the investment. And that assumes no maintenance cost on the generating equipment.
Using humans to generate electricity is simply not cost-effective.
hillikus
03-01-08, 02:46 PM
This is a great do it yourself website to check stuff out at. Lots of bike stuff there also.
http://www.instructables.com/id/Bicyle-Power-for-Your-Television%2c-Laptop%2c-or-Cell-/
-H
RomSpaceKnight
03-01-08, 05:14 PM
Switching over to 12 volt appliances might work. A bicycle could then run a car alternator. Probably easiest thing to rig up.
When I was young and we lived in the country during winter snow storms and power failures, us kids would have to take a turn on riding a bike hooked up to the water pump. We had a well system not municipal water. Half an hour would get us a bath tub full of water.
MCSF415
03-02-08, 06:10 AM
I don't know if this is something like what you are looking for--a stoke monkey by cleverchimp. Check out http://cleverchimp.com/ it says sales are temporarily suspended due to high demand, but I am sure they will resume at some point if it is so popular. I imagine you could modify this product--originally intended as an electric motor assist for extracycles,
CrimsonEclipse
03-02-08, 03:44 PM
I bicycle powered generator is an excellent idea for emergency uses only.
For extended power outages caused by hurricanes, earthquakes, etc.
Since there are already hand powered generators on radios, flashlights,
small TV's, and cell phone chargers, a higher powered bike like charger would
be good for laptops and possibly even a small refrigerator. This should also
be used as a last resort, after the generator runs out of gas and/or the solar
panel fails or produces insufficient (night time, clouds, etc).
CE
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