patrick.net

I defer to NuttyNeutron on how best to charge a battery from an AC source. The alternator in your car does this but I am not sure exactly how the current is converted to be stored. I imagine it is just like the AC adapter that powers your DC electronics from a wall outlet. I have no idea what the energy loss is.

There will always be 12 VDC devices. The next question is which devices have the most options/choices. I am sure that you will probably find 100x more things to use AC power. In many appliances, the power supply converts the AC into DC anyway so maybe you can find the same item in DC variety. Take a look at your computer's power supply for a good example of this.

I think you will find that there are plenty of packaged units with a rectifier/inverter setup with batteries as a backup. The best part about it is the uninterrupted power. If you use AC to power battery chargers that trickle charge a battery bank and have most of the charger power get inverted to 120 VAC, you will have a great setup. Also look at getting low energy items like fluorescent bulbs. One of the best ways to reduce electrical use is getting the right home. I want to get an ICF home. These homes use Lego blocks of Styrofoam with 6inch steel rebar concrete as the structure. They are efficient and act as a thermal battery. The temp does not swing much even with the A/heater off.

Just be warned about the cost. You will pay about 20x more for electricity if you use solar. The wind turbines are a lot cheaper and probably most reliable. I have a hard time finding a day where the wind does not blow where I live. In the SW solar may make more sense.

All I can tell you is do a discounted cash flow on all your options. Target the life expectancy of a turbine or solar array for 10-15 years and run with it.

I plan to one day get tied into a gas line to power a small Honda ICE engine generator. I want to tie that into an ABT unit with a small battery backup for the few seconds it takes to get the engine to rated speed. I would only power an emergency bus within my house.

One of my more crazy ideas would be to get some land under the 435KV high lines and steal power with my own coils via induction. I would call them mycrazy looking lightning arresters :)

We can transmute Throium into Uranium 233

You can create an isotope of Uranium from Thorium? I am not that current on my physics, by this means you can bump proton count by two in each nucleus in a hunk or thorium? Thorium has a high enough atomic number that adding protons would require a great deal of energy. I thought nuclear fusion could was possible only with lighter elements such as hydrogen or helium, and that fusing elements heavier than iron took rather than released energy. I do not doubt you, I am just impressed with the progress.

Let me know when you can manipulate the proton count of common elements to 79 :)

Like an electric train gets it's power from just reaching up close to the lines? That's pretty clever. I don't think they could accuse you of stealing power if you don't acutally tap into the lines. Never thought of that one.

I also concur that a windmill is more efficient than solar but for city homes probably not really practical. A grid tied windmill is just as viable as solar for net metering purposes.

The power is converted into one another with ease. There are some losses, but I think you will find that it would not bother you.

Rectifiers use capacitors to make DC out of AC. Inverters also use capacitors to make AC. Just make sure there are no EMPs to fry all the circuitry in the country.

AC is just so easy to make with a rotating turbine. You don’t have to flip the rotating field magnet back and forth. These babies are not like the radio shack toys you probably played with. The rotors of the generator for most power plants have collector rings to power several large EM magnets on the rotor. This rotor spins at 1800 or 3600 RPM depending of the number of magnetic poles the rotor has.

The stator part (non moving part that connects to the grid) has a bit of power taken off to power the exciter. The exciter converts AC into DC so it can be put on the collector rings of the rotor and flashes the field. This is how you get your rotating magnetic field in the machine to make electricity in the stator. The electric field is static. When you connect the stator to a transformer and send the juice to the world you can make lots of money.

Malcolm,

It ain't the voltage, its the amps that zap. A Van Degraff generator (that thing in physics class that you turn the wheel and see lightning like current flow between the two balls) generates millions of volts and you can put your hand in the "lightning" and barely feel it, as the amps are barely measurable. Auto fuses range from 5 to 30 amps. !2 volts at 15 amps will be a nasty shock, not a little tingle.

Oh transmutation goes like this.

Throium 232 absorbs a neutron and becomes Th 233. The Th233 is very unstable. It beta decays into Pa 233. This means that one of the neutrons in the nucleus is now a proton. The beta ejected is the electron part of the old neutron.

The Pa 233 will beta decay again into U 233.

It is similar to fusion from the fact that by being absorbed in the nucleous, the mass of that neutron is reduced and converted to binding energy. Each later decay releases some heat. It is more a reshuffle of the nucleons by adding a neutron. Neutrons require very little kinetic energy to be absorbed because neutrons don't have a charge to overcome to get in the atom.

http://wwwndc.tokai-sc.jaea.go.jp/cgi-bin/selchart2004?Z=tH&A=232

Find Th 232 add a neutron by going to Th 233. Then click on Th 233 to follow the decay chain to U233. Notice the halflives on each isotope.

One of my more crazy ideas would be to get some land under the 435KV high lines and steal power with my own coils via induction

Nice try. Induction is easily detectable. Even very mild forms such a inductive phone taps and even TV demodulation are routinely rooted out. The British have devices so sensitive that then can drive around, point the device at roof antennas of those addresses that have not bought a BBC license, and nail you for stealing TV signals.

You electric current stealing method actually puts a demand on the flow (much like an AC motor) and thus would make the the power company's generator a slight bit harder to turn.

Headset,

.1 ampres is enough to kill a human.

Headset,

LOL you think a 3.5 million horsepower machine moving 1000 tons of metal at 1800 RPM would notice my loading? They would see line losses before they found me :)

You could make certain isotopes of Mercury into gold with a good neutron flux. The problem is scale. 10^23 atoms per cm^3 and only a neutron flux of 10^12 at most. You can figure out the time required to make that all into gold :)

1 neutron for every 10^11 atoms of mercury! You would be better off making a star ship to catch astroids with gold in them already :)

Rectifiers use capacitors to make DC out of AC

You mean diodes. Some rectifier designs may have a capacitor in it as a filter, but the true work is done by diodes. And if your are thinking of a transformer/rectifier design. that is highly inefficient.

Then click on Th 233 to follow the decay chain to U233

I don't doubt you. My knowlege is too old for me to understand how an isotope of an element with 90 protons can decay into an isotope of an element with 92 protons.

HeadSet Says:
October 12th, 2008 at 6:44 pm
"Malcolm,
It ain’t the voltage, its the amps that zap. A Van Degraff generator (that thing in physics class that you turn the wheel and see lightning like current flow between the two balls) generates millions of volts and you can put your hand in the “lightning” and barely feel it, as the amps are barely measurable. Auto fuses range from 5 to 30 amps. !2 volts at 15 amps will be a nasty shock, not a little tingle."

Correct, I didn't say the voltage zaps. The voltage has to be high enough for the potential to cross the resistance. What you said is correct and not different than what I said, the reason the physics ball doesn't kill you is that the amps are almost nothing.

It can decay that way via beta decay. In the process a neutron becomes a proton and beta particle.

Headset, I am tired and typed that in error. diodes are wonderful electrical check valves that can make the DC. I do think however the rectifiers do use capacitors to do it. Don't make my head hurt by asking me to turn a sine wave into a DC signal and then back to a semisine signal :) It made my head hurt years ago.

If you reduce the voltage, the amps go up and that ball will kill you quite quickly.

Same way powerlines don't melt. The voltage is high and then stepped down. AMPs and Voltage are related to each other. You can lower one by raising the other.

This is proof that nuclear engineering is easier than EE. All I had to do was count neutrons and learn some crazy math that required me to get a minor in math. Some differtial equations, diffusion theory, and transport theory were easy to solve.

EE have to do an evil phaser dance to figure out what is going on in a circuit. I hear they even eat their young :o

It can decay that way via beta decay. In the process a neutron becomes a proton and beta particle.

I see, thus is stays a 233 isotope. I suppose that right after the U-233 is formed, it immediately experiences fission from collisions with any remaining neutrons?

I realize the "capacitor" verses "diode" was more a typo. That's why I wrote "you mean diodes" rather than "your mistaken."

http://en.wikipedia.org/wiki/U-233

Read this for a good run through on the black magics of nuclear physics. This show the trick of turning stuff into other stuff. The true art of alchemy.

U233 has a longer half live than the daughter isotopes and will last a while. It will last long enough to ge given a chance to fission on its own when a neutron gets inside it nucleous.

Same way powerlines don’t melt. The voltage is high and then stepped down. AMPs and Voltage are related to each other. You can lower one by raising the other.

The reason power lines do not melt because resisitance is low. Heat generated by current flow is related to resistance. It is true that the step down transformer decreases the volts and increases the amps, but that is a side issue. If the power company feed 220 volts (what is delivered to the house "fusebox") into the line at the source, they would have a very short transmission distance. Think of the hose analogy. Open the nozzle and get high flow at low pressure. Can't squirt very far. Tighten the nozzle and you have less water flow (amps), but with enough pressure (volts) to squirt across the street.

Nut,

Good article. Thanks.

I agree with this as well. Not sure why you disagree though with the melting, I will have to check. I completely agree that the 220 volts wouldn't go far that's why it is transmitted at high voltage to step down at the source. My understanding is that was the objection to AC until they discovered that transformers could be used. It is just like how cable in the house has to be a certain thickness or it will melt. I will try to find a source but we are now literally at my borderline of knowledge in this area.

I've heard the hose analogy before about volts being the pressure inside but you just conceptulized something for me about the spray so I thank you.

Headset, I believe it is Joule heating which is reduced by increasing voltage.

http://en.wikipedia.org/wiki/Electric_power_transmission

Again, we are moving into uncharted territory for me so I don't feel comfortable pushing any further than sharing this link.

Malcom,

If I have a wire of a given resistence, increasing the voltage will cause the wire to heat up. That is counter to using high voltage to stop wires from melting.

If I have a wire with high enough resistance, high amps with low volts will not flow through it. If I increase the voltage to make amps flow (even though the amps are decreased), the wire will heat up.

Thicker cables have lower resistance than thin cables of the same material. AC does have that "skin effect," and benefits from stranded wire, but my point still applies.

Actually, my main point was that I want off-the-grid houses to evolve to max use of DC appliances, since I thought that converting from battery DC to house wire AC and back to internal appliance DC was wasteful.

Malcolm,

I posted the above before you last post. I was unaware of the joule heating factor. Good link.

That makes sense. Also, the low volts not flowing makes sense as that goes back to the battery example. Sort of like being constipated I guess, not enough pressure to push through.

I knew thicker cables have less resistance hence minimum guages for power requirements, I didn't know about stranded wire. I always thought that was to get the same effect from less materal, now you have enlightened me on another thing since I didn't know it was the surface area that mattered. Interesting.

I partially agree on the last point. I hope I helped you there. I don't see any reason to go from DC to AC to DC. I say DC to DC step it up or down with a voltage regulator (pretty sure that is the right component, but you know what I mean, the little gadget that you can plug into the lighter adapter and click whether you want 6, 9, 12, 14..etc. volts.) and if needed use an inverter on a seperate circuit for AC power. A pure sine wave inverter gets expensive, but the modified sine wave inverters are reasonable. Their only limitation is that they create noise on stereo equipment. I think you will find the power loss to be very negligible.

Here is another thing that you might find interesting. One of my business partners had an idea I thought was pretty creative. He proposed designing an EV charging jack as part of a typical home solar inverter. He believes you can rapid charge an EV with the DC current directly from the panels. Again, the concept is simply adding a seperate circuit to the same string, therefore you wouldn't have the waste you are talking about using AC to charge a DC EV. The excess of course (when there is no car there) would go the normal route back out to the utility as AC. The flaw of course being most EVs will be charged at night, but I thought it was a creative idea. Maybe commercial business could offer EV charging from their solar systems to their employees or customers. I like to try to find a potential for an idea instead of just shooting it down.

LOL, I was typing and didn't see your last post either.

Nutty, is it the volts or the amps that will melt an underrated wire?

technically, I believe it is the current density

Power = (I^2)*R (resistance heating)
dV = I*R

I=current
R=Resistance

If you can raise the voltage, you can reduce the line losses. This is why high lines are stepped up to the thosands of volts that they run at. The reason for this is the decreased ampes on the line. The power is carried away on the wave action of the electron going back and forth.

http://www.theoildrum.com/node/4636

We have the solution to this problem.

Looks like my man Krugman has won the nobe prize for economics.
Always a good read when he is not wonking politics.

Can we start a new thread?
Just so I don't have to wade through this garbage?

Guys, I have not been reading this thread yesterday, but take it from an EE with quite a few years of additional education on top of the basic degree (if you catch my drift):

There has been a few misleading and/or errant statements made about certain electrical topics in this thread yesterday. I'm not quite in the mood to dissect all of it, but let me just clarify one or two points.

First, I should caution that there are many different ways of saying the same thing here, but let me just try to say it one way and see if that makes sense to everyone.

The reason that high voltage in a transmission system does not translate into hot and melting wires is that the VOLTAGE DROP along the wire is quite small. Note that there is a difference between the voltage drop along the wire and the voltage drop across the load that is connected between the two (or more) wires. The voltage drop across the load does (mostly) productive work. The voltage drop along the wire is plain loss.

More detail:

The reason that high voltage transmission is more efficient is that lower current is required to transmit tghe same power (P=V*I, V goes up, I goes down, for constant P). The loss in the wire is P(loss)=I^2*R, with a lower I than before.

Of course, there is more to the story than this, because there also are losses in the insulating medium (or "dielectric") between the wires (air, rubber, oil in transformers, etc etc). At some point, diminishing returns are going to set in when you increase the voltage, because the insulation gets prohibitive, the wires have to be spaced too far apart, etc etc etc.

Now, as I had mentioned a few months ago, one of the reason that DC transmission systems can be more efficient than AC , is that dielectric losses tend to be lower when there is a constant electric field rather than an alternating electric field. The latter is jerking the bound electrons in the insulator around quite a bit, and energy is lost. This is all a bit folksy a way of saying it, but you get the idea.

I agree with Fuzzy about current density. It is just an alternative way of saying the same thing as I just did. And I will defer to Neutron on most things nuclear :-).

Oh, I did not see Neutron's 1:35 am post. Also correct.

Duke,

I can agree that discussion of energy and energy conversion systems is a bit OT, but it sure has a profound effect on the economy in general and housing matters as well.

I think those exchanges are very worthwhile.

Duke,

Yeah, congratulations to Krugman, one of many decent economists that have advocated buying preferred equity rather than buying bad assets.

Duke Says:
Can we start a new thread?

It's up.