pedal power - Page 2

 

Adding to the hot water is not such a bad idea.  Something is clawed back.
Not a lot but something.

He could be in a gym on an electrically power treadmill. What a silly idea.

  On 7/15/2012 12:50 AM, John wrote:

http://www.econvergence.net/

If you pedal all day you may get a kWhr or so, do that every day for a
month and you could easily get 30 kWhr.

Let's see who is laughing then when you've saved a couple of quid!

Jeff

 On 15/07/2012 18:06, j wrote:

One of the more expensive electricity providers here that would equate
to a saving of around £7.00 per month on the electric bil. Roughly
$
1.00 in US Dollars. That would be an almost 20% saving on my electric
bill so worth doing!

I am unsure of how many watt hours of power you would be able to
generate from a peddle powered set up though. Some of the places selling
them seem to sell 300 or 400w units so if you were maxing that out then
1kwh of electricity may take 3 or 4 hours to generate. Realistically
agreed you would be talking a day to get around 1kwh as you are likely
to generate around 200w maxing out and pedaling at a medium sustained
speed probably around 100w give or take 40w.

I have read that a belt driven pedal power generator is more efficient
at higher speeds than a roller type (direct drive) one and that it can
help to stabilize the energy output from the riders legs.

If you can afford to buy the parts cheaply I think it may be worth doing
regardless of whether it takes a year or several years to pay for
itself. If you have the means to buy those parts they would start paying
for themselves straight away in the form of lower energy bills. You
would also have an emergency system in case of power failure.

If you use a grid tie-in inverter I don't see any problems? Your
electric meter will spin backwards or won't spin forwards as quickly.
Here in the UK we are free to supply our own electricity back to the
grid after a court ruling. They can't prevent us from doing so. We can
simply plug into the mains and off we go.

Grid tie-in inverters to convert to 240volts here can be had quite
cheaply. Alternators can be picked up from breakers yards quite cheaply.
The only skill I need to do this will probably be welding which I
already have some practice in. Then a frame and either roller of belt
type pulley system to an alternator or permanent magnet motor.

If it takes one minute to supply two minutes of usable power, that is
not significant I agree however it is more significant per cost than you
could hope to muster from Solar and most other renewable forms of
energy, and if you use and own a bike anyway why not store some of that
energy and use it to reduce your electric bill?

Cheers
John

 

Car alternators are VERY inefficient.  You need either dedicated
generator or a good DC PM motor to use as a generator - check locally
for people giving away treadmills.  The most common treadmill failures
are belts, control panels, and power supplies.  The motor usually
survives.

Even so, you are unlikely to produce enough power to make it worth the
effort.  The human body cannot produce even a fraction of a horsepower
for extended periods - 1 HP = 746 watts.  If you're in good shape, you
*might* produce 1/3 of that - but don't expect to do it for hours.



Online references:
http://www.mattshaver.com/bikegen/index.htm

Check the prices here for the parts needed:
http://www.pedalpowergenerator.com/#FREE

You won't be selling power back...

 
One horsepower was the work a horse could do averaged over 24 hours,
so if a mine owner needed to own ten horses to keep his mine pumped
out he should order a 10HP steam engine.

Horsepower and human power:
http://en.wikipedia.org/wiki/Horsepower

"When considering human-powered equipment, a healthy human can produce
about 1.2 hp briefly .. and sustain about 0.1 hp indefinitely; trained
athletes can manage up to about 2.5 hp briefly[11] [12] and 0.3 hp for
a period of several hours."

Watt padded his estimate to protect against customer complaints, since
the mine owner could easily see if the 10HP engine was keeping the
mine as dry as his 10 horses had.

jsw