types of energy can we harvest?
Reach
Posts: 107
What types of energy can one harvest? How much surrounds us everyday?
As I type this I wonder how much energy is at my reach.
- Sound
- RF
- Radiation alpha, beta, gamma etc.
- hydro
- wind
- solar
- thermal
- gravity?
Is the essence of harvesting energy primarily the antenna?
As I type this I wonder how much energy is at my reach.
- Sound
- RF
- Radiation alpha, beta, gamma etc.
- hydro
- wind
- solar
- thermal
- gravity?
Is the essence of harvesting energy primarily the antenna?
Comments
http://science.nasa.gov/science-news/science-at-nasa/2013/10sep_firestation/
As for gravity, there are tides generated by the moon and sun. I'm still waiting for somebody to harvest energy from terrestrial tides, small flexings of the earth's crust caused by the moon and sun.
this clever solution is tailored for vibration for instance
http://www.perpetuum.com/
If you check the web you can find a lot of solutions... temperature difference come to mind.
both temp and vibration are not using antennas
Massimo
Personally, I 'd love to see a modern Sterling Engine (like the diaphram design) exploiting this to either make ice (and a means of cooling a building) or directly cooling buildings. Off-the-grid air conditioning for a world that is over-heading. The human brain goes into heat stroke at temperatures higher than 42 degrees celcius, and there are a heck of a lot of sub-Sahara societies that may not survive a heat wave in the near future. Similar situations exist in India and Pakistan.
The goal... make the equivalent of 2 tons of ice per day for the average small dwelling, and at a low cost.
Even applying the Chinese grown cooling techniques to areas such a public parks might create safe-zones of marginally cooler temperature in the inner city and avoid disaster. The elderly and children are most at risk.
Study thermodynamics and the Carnot cycle.
I've attached my current plan for the core of a micro-power propeller system. The circuit attached to P25-27 allows sampling of the circuit state. To see if the super capacitor is over-charged, output low on P25 and P27, make P26 an input, and if P26 is high the super-capacitor is over-charged. (so waste some energy using P24) To measure the clock frequency, set P25, P26 output low, and P27 output high, next make P27 an input and time how long it takes to go low. (the clock frequency tells you some mix of operating temperature and voltage) To measure light levels set P25-27 output high, then make P25 an input and time how long it takes to go low. And finally, don't leave any of the IO pins floating, as an input crosses the logic threshold it can draw up to 90uA.
Marty
Typical devices are optimized to heat or cool, but can also generate power with enough temperature differential.
Stick one on your window on a cold winter night and measure the voltage.
https://www.sparkfun.com/products/10080
A more legal and interesting method I'd like to see used is ocean current/wave energy. I see a lot of potential there.
How much energy do you want to harvest?
A neighboring farm I knew decades back ran a long electric cow fence under a power line that crossed his farm. It worked very well with no "ticker" box on it at all.
Sucking power from the power lines with a big coil in your roof is illegal. There are stories of guys in England getting busted for that.
On a big scale solar concentrators with Sterling engines to convert heat into electricity sounds like a, should I say, hot topic at the moment. Check this out: http://www.youtube.com/watch?v=Abo_V6pYTSI . Try to ignore the fact that Margot Gerritsen is probably the most beautiful mathematics professor the world has ever seen:)
Seems the Chinese are pledged to investing trillions of dollars over the next ten years into solar power.
Maybe it's not a form of energy. But would you consider it a source of energy?
I guess that raises the question of whether or not a force is a source of energy.
Cast you mind back to when you were 13 years old or so and they were teaching you science in school:
"The most common definition of energy is that it is the capacity of a system to perform work"
Gravity is a force. By itself it can do no work. Imagine the gravity field around the Earth. There's loads of it, all around, not necessarily any work available though.
OK. Now lift a heavy rock of mass "m" up to some height "h".
Clearly that rock can fall back down and do work. Smashing something, or just making heat on impact say. Or it could pull a string that turns a generator that lights an electric light for a short while as it falls.
How much energy?
Clearly the bigger the rock (bigger m) the more energy we have.
Clearly the higher we lifted it (bigger h) the more work it can do as it falls, the more energy.
Oh, and don't forget, the stronger the force of gravity at the surface of the Earth the more energy we can get out as it drops. Let's call that "g".
So we end up with energy E = mgh.
So there we go. To get energy from gravity you also need mass and height. That is the "system" in the definition above.
That is of course how hydroelectric power generation works. Water up hill moves downhill turning something on the way so we can get power out of it.
BUT..where did that energy come from in the first place?
Newton would be very distressed that the simplest things he had to say are now a deep mystery to so many.
I'm just trying to figure out where the source of energy might be.
If gravity is not a form of energy. And a bucket of water is, by itself, not a form of energy. And yet we can get energy out of a bucket of water falling....
Does that mean the "source" of energy is the height through which it falls?
All energy in our universe came from the great premordial black hole created in another universe (the mother of all universes) or possibly a computer simulation with Planktime sized clock ticks.
Sterling engines are fascinating. Small ones can be powered by a hot cup of coffee. I have several cans in my garage collected for Sterling experiments. The cans often get evil looks from my wife (another source of energy).
I'm frustrated that we usually need some kind of mechanical energy to create electricity. Solar panels are an exception of course. Surely light and heaters (current) are not the only ways to bump electron orbits.
When water is heated, it evaporates and rises until it condenses and falls as rain. The forces of gravity makes it fall and run downhill at some point turning the water wheel. Energy goes in, energy goes out......no such thing as a free lunch!
Energy harvesting can be fun, so can making what you have more efficient. Change/wash filters, clean off those fan blades, tint windows, etc etc. I see a lot of business owners chasing down cheaper solutions to save money when they don't realize taking care of what they have would save them quite a bit as well. Oh well...
I purchased a nice solar setup a couple years ago and HOA said NO. Don't take no for an answer when it comes to being efficient
http://news.yahoo.com/study-wind-farms-killed-67-eagles-5-years-160226373.html
And erco... the winning design could probably be made out of wood.. :-)
Edit:
This analogy can be applied to several other energy harvesting techniques. The key is finding the proper impedance match between your input versus your output, and understanding resonant frequencies can play a big part here. Not only electronic but mechanical resonant frequencies are at play here.
Cows generate a tremendous amount of methane in their flatulence, and are considered a major contributor of greenhouse emissions that could lead to climate change. What we need is some kind of device that hooks up to the backside of the cow, traps this gas as it is emitted (which is nearly constantly), compresses it, and then contains it for easy collection. The methane could then be used for various kinds of energy uses.
So, wind technology really does hold a lot of promise. Only this is a different kind of wind.
I suppose, if gravity turns out to be in fact a wave then its a form of energy correct? All we would need is a big coil and a diode to harvest it - so to speak.
Chemical reactions seem appealing to me but I am sure the byproducts are toxic.
I wonder why the universe insist that making things hot is easier than making them cool. Burning a fire as an example, where is the reciprocal - freezing from a type of plant?
I am fascinated by Stirling Engine's but I am not so sure it would be better than a peltier. At least a peltier converts the heat / cold directly into electricity but then again the Stirling engine might be cost effective.
I ask if anyone knows of an function that calculates the amplitude of a parabolic paraboloid reflector when employed as a solar heater? I would like to crunch some numbers first before using a parabolic paraboloid reflector sitting on top of the cool ocean with the light focused on a Stirling engine. Or, instead use a peltier in the absence of the Stirling engine
Here is my crude photo
1. blue is a negative heat source a heat exchanger in the sea
2. black is my antenna (reflector)
3. red is heat source
4. peltier or Striling engine is to be decided.
This may also provide fresh water if modified in a manor with currant devices.
.
Have you read about Bet'z Law? I find it fascinating how inefficient wind power can be 59.3% if I recall the math correctly. I guess we would need a great wall of wind generators to compensate for the lack of efficiency.
Duane J
Think of it this way. If you extract 100% of the power in the air the air must be stopped and would pile up behind turbine.
Betz showed that about 59% is the maximum theoretical efficiency by slowing the the air down and still clear the air away on the back side.
As I recall good wind turbines extract a bit more than 45% of the wind's available power.
That is pretty close to the the Betz limit.
Duane J
Then I guess all we need is a height-harvesting machine?