Daily GUIDE-ance:

Tuesday, May 20, 2008

Alternative Energy

aaaraaaaaaghraghgh!!!!!!

-Sorry had to get that out of my system-

$4 gas. It sparked a conversation this weekend between the Moose and I. Alternative energy sources was the topic.

A few years back Moose and I kicked around the idea of human powered electricity. It sounded pretty good. What we thought was: "lets get a stationary bike and rig it to generate a current."That shouldn't be too hard to do. We imagined installing this invention in places like homeless shelters- anyone who needs a job can just go in and peddle- and in prisons- you could give the guards masks and whips and transform beatings into electricity.

One problem with the bike concept was that the current generated would vary with however fast the convict/hobo peddled. That type of current would be anything from useless to annoying to fatal for most real applications (imagine pulsing light bulbs, microwaves, radio volumes, life support systems). My solution was to convert the energy generated by the peddler first into a form that could be released uniformly, then convert that to electricity. Some sort of mechanical water pump that the bike drives water to a reservoir on top of your roof say. The water can then be released at a uniform rate to generate a uniform current.

Eventually I took the time to do some research and some simple math/physics on the concept to determine how much electrical power one guy might be able to generate on a bike. Here is what I found out.

Basic lesson:

Q: What is a Watt?

A: A Watt is a measurement of Power, or in other words, energy used per time. In physics:
1 Watt= 1 Joule per sec

Q: Ok what is a Joule?

A: A Joule is a measurement of energy, specifically 1 Joule= 1 Newton meter. (A Newton is a metric measurement of weight or force,- about .273lbs) (a meter is 3.28 ft,) so:

1Joule = .273lbs x 3.28ft = .895 ftlb

One way to think of this is to remember that 1 Joule is the amount of energy it takes to lift .895 lbs 1 foot off the ground on Earth. (or you could say that 1 Joule is the amount of energy it takes to lift 1 lbs .895 feet off the ground- or any combination of feet and lbs that multiplies out to .895)

Q: Your power bill most likely reads in kWh (kilowatt hours). What is a kilowatt hour?

A: A kilowatt hour is a measurement of watts used in an hour. It is a measurement of energy, like the Joule.

1kWh= 1000watts x 3600 seconds = 3600000 Joules.
Hence 1 kilowatt hour = 3600000 x 0.895 ftlbs.= 3.2 million ftlbs

OK... so lets assume you are going to rig your bicycle-generator up in your living room. Lets say you are going to pump water from your basement to the top of your house- for a potential energy drop of 30ft. that means to generate 1 kWh, you will need to move 107,000 lbs of water from basement to roof. Given that a gallon of water weighs 8.34 lbs, you are looking at 13,000 gallons of water moved from basement to roof to generate 1 Kilowatt hour of power.

That's a lot of gallons.

Q: How much does a Kilowatt hour cost you?

A: Well, it varies from place to place. You can take a look at your power bill and find out what it is for you exactly but chances are its about 8cents.

So. You get on your bike and work up an inhuman sweat to move 13000 gallons of water up 30 ft- (I hope you can imagine this - If you can't, try carrying 13 gallons of water up the stairs 1000 times- it should give you some idea)- thus generating 1 kWh of energy- and how much money have you saved? About 8 cents.

The moral of the story: Alternative power is not as simple as it sounds. One of the main things that gets forgotten in the debate of how to manage our energy needs is the sheer titanic power represented by fossil fuels. We use electricity soo much that we take it for granted. Trying to imagine what it would take to create this type of power using just your body is a good reality check.

19 comments:

Brad Carter said...

Why moving water, though? Why not work out something more realistic like lighting your home.

Also, that 8 cents would need to go towards food to power the human.

Brad Carter said...

Also, you should read this article about gyms that are using humans to power lights.

Eyepoke said...

Why water?

It doesn't have to be water. For the purposes of this article using water is just a useful way to think about the how much energy an 8 cent kilowatt really is. Its a frickin lot!

The thing is, the system I describe is an ideal- one with no inefficencies at all. Obviously such a system is not possible in reality, but the point is- No more effecient system is possible! Any other system you might work out would by definition be less efficent than the one I describe.

Eyepoke said...

Its worse than that, it's physics, Jim!

timpani76 said...

Ooooh, I saw some awesome giant windmills when I drove up to Minneapolis to see Danielle. Minneapolis is supposed to be one of the "greener" cities with lots of bike/walking trails and big walking only sections of the city.

I think windmills are a great idea, and they look really neat too (at least to Elise and I).

Aren't we doing something with corn too in Illinois? E-85 or something?

But, it does seem like most of these alternative means are just ways to reduce our dependence on fossil fuels, not eliminate the need for them altogether.

I wonder if we will ever get to the point where we will all be plugging in our cars every night?

Anonymous said...

Read the article. 300 watts is what they clam to be able to do with human powered electricity.

That's 0.3 kWh per hour. Not quite 3 cents an hour's worth of power. Please correct me if I am missing something obvious here!

Don't get me wrong, there are some decent valid ideas out there for alternative fuel, but there is also alot of hype and propoganda.

I can't speak to the validity of wind power, although I have been researching solar. More on that later maybe.

J

Dana Cheryl said...

Plugging in out cars... I wish! I really, really do. Gas hit $4 a gallon here too. I read some stupid article on msn.com about how great it is. The moron went on to say that what America really needs is $7 per gallon. I say we force all the city dwelling elitists out to rural America and see if they then think $7 a gallon is a good idea!

lizS said...

your mom does like obama.

timpani76 said...

I missed it. What does John's mom liking Obama have to do with the energy debate? Or is this a new kind of insult?

"You're momma likes Obama!" Or something like that?

Bruce said...

on the bike thing j, there is a device called a cappacitor that regulates voltage output. pluss you can insted stoor the energy in a battery to be used later the small amount of power put out by the human does not matter because you have trickle chargers ment to charge the battery at a slower rate(does a better job than fast). ethinal sucks. at this point in time it is a huge waist of corn. whats the problem with that? have you checked the price of any thing at the grocery store recently?(milk is almost $4 a gallon) the good that could come from $7 is that people will finaly get fed up and do some thing about it. like conserve or demand that the government do some sort of manhatten project for energy. we do wast the oppertunity to get power all the time. j back to your water idea. how many gallons of water flow down the mississippi every hour, yet not one hidro plant on the entire river? and the stairs is a bad annaligy. you are also carying your self up the stairs. i personally think the biggest oppertuinty we have is solar power. ill let some one else have a turn now.(and sory again about my spelling(and i dont care about caps))

Brad Carter said...

Advances in solar power have gotten pretty exciting lately. EcoGeek (a blog I'm subscribed to) is constantly showing new types of solar cell concepts. They're coming in thinner and more cost-effective sheets now. Some are roof shingle replacements. Some of them can even be painted on. The future of solar power is looking pretty good.

http://www.ecogeek.org/
http://www.treehugger.com/

Those are a couple of blogs that discuss alternative energy news.

lizS said...

read today's insult, and you'll understand my comment. and john has a link i think you should read, bruce, but i don't know it right off the top of my head, and he'll be home soon.

timpani76 said...

Ahh, I see the insult now. My mom also likes Obama (I'm guessing, since she voted for B Clinton)

Anonymous said...

Ok, I knew someone would complain about the stairs analogy because it does not take into account carrying your own body wieght...

First off its just a rough "scale of magnitude" type thought experiment. Second off I figured that since I was leaving out the person's body wieght, I'd only suggest walking one flight of stairs instead of the three you would need to reach an altitude of 30 ft. The analogy is as good as I intended it to be. (pretty good, but not exact)

Point two:
It does not matter how clever a capacitor/battery system you might be able to rig up to harness the power generated by a dude on a bike.

All I have done in this article is use freshman level physics to show how much energy is represented by 1kWh of energy. It is the equivalent of what it would take to elevate 13000 gallons of water 30 feet on Earth.

Any mechanism that dervives 1kWh of energy from your body is going to make you work at least as hard as you would elevating that water that distance by any mechanism (using only your body) you can imagine.

J

Anonymous said...

It is my opinion that although there are some good ideas in the alternative energy world, there is also alot of nonsense that is not subjected to serious critism and evaluation. I likethis article.

J

Bruce said...

i think solar is totally the way of the future. but i would not mind a wind mill in my yard. i could use it is lew of a shade tree which takes 20 years to grow. i was talking to my martial arts instructor tonight, he just bought a scooter. 100 miles to the gallon. next time you drive down the hiway(or any where or any time for that matter) at rush hour, look at all the cars that have only 1 person in it. i think it would be great if we found a way to reduce what we need. but we need research reseach research.

lizS said...

we need to update our public transportation, that's for dang sure. we are so far behind other countries in this area, it's shameful. we have a few cities that are okay, but most are not. and the research has been done. just go to france or england ect. and copy.

Dana Cheryl said...

We're too busy being in debt to China to develop top notch public transpo... Although on my mish I got by just fine w/ the St. Louis metro system. Even the East St. Louis side was good. Not my favorite place after dark but no metro station would be...

p.s. Have any of ya'll checked out the "crazy lady" on the train on youtube?

Eyepoke said...

I agree withy Dana. Given the government's track record of sucking at everything, the fewer things out there that start with the word "Public" te better.