Dave has completed 44 years in the Broadcast industry, working in operations, engineering, training and project management.
What is Electricity?
Essentially, there are two kinds of Electricity: Static Electricity and Current Electricity. Both depend on electrons, the tiny charged particles that orbit the nucleus of an atom.
Static Electricity has been known about since earliest times, though it was not properly understood until the discovery of subatomic particles a little over a hundred years ago.
Static Electricity on a large scale causes lightning and on a much smaller scale can give you an annoying shock when you step out of a car. You can generate it simply by combing your hair with a nylon comb. The electrical charge transferred to the comb will cause it to attract the hair, or, if you like, to pick up little scraps of paper to entertain the kids.
Though interesting, static electricity is of limited practical use. For the remainder of this hub, we'll concentrate on current electricity which is a flow of electrons through a conductor (usually a copper cable).
A Little Science
First, we need to talk a bit about Energy. In Physics, Energy is defined as the ability to do Work. (Everyday examples of Work are: climbing stairs, loading a truck. anything that involves moving mass).
Some of the common types of energy are: heat, light, kinetic energy (movement), chemical energy, gravitational energy and of course. electrical energy.
In Physics, the Law of Conservation of Energy says that energy cannot be created or destroyed. It can only be transformed from one type to another. This means that to generate electricity, we have to use another kind of energy to fuel the process - in this World you don't get something for nothing!
In the 19th Century, Michael Faraday carried out the pioneering work that linked Electricity and Magnetism. In particular, he showed that an electrical current is generated in a conductor moving in a magnetic field.
The effect is greatly magnified if the conductor is replaced with a coil or coils of copper wire. If these coils are mounted on a rotating shaft or armature, continuous rotation will produce a continuous alternating electrical current. This is how nearly all electricity is generated today.
Now that we have a device (the generator, or alternator) that converts mechanical energy (rotation) into electrical energy, the next problem is how to obtain the mechanical energy to keep the alternator spinning. Here is a brief summary of some of the viable ways of generating electricity on a commercial scale.
A Basic Alternator
The Modern Alternator
Faraday's electrical machines were laboratory experiments. Technology has developed his ideas dramatically. The modern alternator does not use permanent magnets but an energised coil instead, to produce the magnetic field. Also, his invention has been turned inside out, with the field coils mounted on the armature (now called the rotor) and the electrical current induced on the stationary coils (the stator). There are normally three stationary windings in the stator, spaced 120° apart, to produce 3-phase alternating current, the modern standard for distribution.
The Commercial Options
In a coal or oil fired power station, the fuel is burned (converting its chemical energy into heat) and the heat used to convert water into steam at very high temperature and pressure. This then drives a steam turbine, a device which harnesses the energy in the steam (heat and pressure) to produce rotational movement (mechanical energy). The rotating shaft of the steam turbine is coupled to the armature of the alternator, so the final result is electricity.
Windmills have been around for centuries and all have harnessed the energy of moving air (wind!) through rotating sails or fan blades. Traditionally, the mechanical energy was used directly, to turn a mill wheel. A modern wind turbine simply couples the rotating shaft to an alternator armature. The last link in the chain is always the same - electricity from mechanical rotation.
Hydro Electric Power
Here, the source energy (there always has to be one!) is gravitational potential energy. A mountain stream is dammed in a high place, to create an artificial lake or reservoir. Farther down the mountain, the power station is equipped with water turbines. These are simply highly efficient versions of the old fashioned water-wheel; effectively they harness the kinetic energy of a carefully channelled waterfall to produce mechanical rotation. The rest you know.
Tidal Power and Wave Power
These new technologies extract energy from the long-term bulk movement of water in a tidal estuary and from the short-term wave motion of the surface. The principle remains the same, to harness the 'free' natural energy in moving water to drive a mechanical turbine.
Solar Power - local
In a sense. all energy on Earth is solar energy, as even fossil fuels are chemical 'memories' of ancient sunshine. But we're talking here about generating electricity from solar energy, and strangely enough, it's not very easy. The problem is that you can't easily convert sunshine into mechanical rotation to drive alternators on a commercial scale. Solar panels have no moving parts, and so the electricity they produce is 'DC' or direct current. This is like the electricity from a battery. It's great for local use, e.g. running a small irrigation pump, but the big problem with DC is that it is hard to distribute. (No time to explain that now - maybe another hub!)
Solar Power - commercial
Photovoltaic units, as described above, are best suited to localised applications like space or water heating. However, commercial-scale solar power plants, though still expensive to build, are becoming viable, the more so as the price of fossil fuels increases.
No single design for commercial solar power has yet won through, but all are based on the same idea - a large array of reflectors to collect the sun's rays and focus them onto a receiver which is effectively pipe-work containing a heat-absorbing fluid. Technologies are already well developed to store the collected energy as heat and to convert it to electricity using steam or gas turbines at a steady rate, night and day. The biggest problem is that the sun moves (OK, the Earth rotates!) and so ingenious tracking mechanisms are needed to make the reflectors follow the sun through the daylight hours.
Ironically, the part of the world best suited for deploying this technology is the part that least needs it - the oil rich deserts of the Middle East.
This is another underdeveloped source. If you drill down into the Earth's crust, at first the temperature drops, because the sun's warmth can't penetrate. But deeper, the temperature rises. Volcanoes are evidence of this - molten lava is pretty hot! That well of energy is there to be tapped. As always, the final conversion process is the familiar steam turbine. And, like solar energy, it is environmentally friendly, provided you don't accidentally trigger a local volcano! But it is not as simple as it seems. The process of taking heat from a hot rock cools the rock locally. There's plenty more heat surrounding it, but can it flow quickly enough to your collectors? Again, it's another technology whose time will come, but not a panacaea.
This is the controversial one. Nuclear fission is a process in which unstable (radioactive) atomic nuclei break down, releasing energy in the form of radiation (escaping particles). By concentrating these nuclei together, a controlled chain recation is produced releasing huge amounts of energy which is used to convert water into steam. The process of generating electricity in a nuclear power plant is simply by steam turbine, exactly the same as in a fossil fuel plant. The public fear of nuclear power is twofold: the risk of meltdown - an uncontrolled nuclear reactor is not very different from an 'atomic' bomb; also the by-product, radioactive nuclear waste, is none too pleasant.
As an aside - Nuclear energy does not obey the classical Physics law of conservation of Energy. It does however obey the Modern Physics law of conservation of Mass-Energy which allows for interconversion of matter and energy according to Einstein's famous equation E=mc² This fundamental difference means that Nuclear Energy is potentially the most fruitful source of all. It is important that proper scientific research & development into nuclear energy, and Nuclear Fusion in particular, should be allowed to continue.
A Wind Farm in UK
Comments, newest on top
Dave McClure (author) from Worcester, UK on July 20, 2013:
How about making a scale model wind generator using a bicycle 'dynamo' and anything else you can find to make the blades, axle etc.
ujwala on July 20, 2013:
can u suggest me a project please..
Dave McClure (author) from Worcester, UK on October 31, 2012:
Sorry but it's exactly the same answer. The car doesn't generate wind. It turns stored chemical energy into kinetic energy. To increase efficiency, you streamline the vehicle (minimising air resistance). If you want to extract energy from the movement through the air, you will inevitably increase the drag by more than you gain.
Eddyramor on October 31, 2012:
I was thinking along the line of perhaps a car that is using a battery to start like the abandoned Joule concept in south Africa. But instead of plugging it in you just have to use the same mechanism used to charge the battery using smaller efficient wind turbines. I dont know much again but I do know that if you are to carry a huge turbine you will subsequently need more fuel for the extra load. I just feel if enough resaerch is made people can generate electricity using moving vehicles, but whether or not it will be enough ELECTRICITY to move the vehicle I am not sure. THE IDEA IS TO USE WIND TO GENERATE ENOUGH ELECTRICITY USING WIND AGAINST THE MOVING VEHICLE. DOES THE WIND TURBINE USED IN ELECTRICITY GENERATION USE FUEL? MY POINT EXACTLY.
Dave McClure (author) from Worcester, UK on October 30, 2012:
Because that would be a perpetual motion machine which is impossible. The car uses fuel to move through the air. If you attached a wind turbine to the roof to generate electricity, you'd have to use more fuel to overcome the extra drag. You can't get something for nothing in this game!
Eddyramor on October 29, 2012:
I dont know much about electricity, but I do have a question to ask if you can help. If electricity can be generated using wind energy, then why are we not having cars that can use the wind generated by the car in motion to generate electricity? How much electricity can the wind generate?
Dave McClure (author) from Worcester, UK on October 25, 2012:
You want a comic strip version?
Anonymous on October 25, 2012:
Its so boring! Make it more interesting
yogesh on August 31, 2012:
It's nice to understand but give new idea to generate electricity,for my satisfaction.
ms bitchiynes on June 06, 2012:
hello wake up meel the rose and give me my dam answer ............ im still waiting after 2 year please man im writing a test about this how am i surpose to learn with nothing about how t generate electricity
MIXER on April 04, 2012:
Can you write some information about the conversation of lightning into usable currenet electricity?
dkjfiaersj on March 24, 2012:
thanx that helped me
Dave McClure (author) from Worcester, UK on March 06, 2012:
Fine mind you have there ;)
Anonymous on March 05, 2012:
Couldn't understand a word. I tried reading but my mind just went BLAH BLAH BLAH!
Abdulbasit Abubakar on March 03, 2012:
I Dr. Abdulgt i apreaciate your activity but what are the steps and the engeine that will be use in the process of generating electricity through biomass. Thanks alot
Dave McClure (author) from Worcester, UK on February 21, 2012:
In theory, if you can burn the waste, you can use the heat to create steam to drive a turbine. In practice, it might not be efficient enough to be worth doing.
Annomous on February 21, 2012:
Can we generate electricity from waste materials
Dave McClure (author) from Worcester, UK on February 19, 2012:
The hub discusses eight well established methods of doing just that.
s.p.prathap sobhan on February 19, 2012:
Sir, how we produce an electricity without using electricity?
Dave McClure (author) from Worcester, UK on February 07, 2012:
It is, but being a gas it's less convenient that liquid fuels.
manoj on February 07, 2012:
why the hydrogen is not used as a fuel
Dave McClure (author) from Worcester, UK on February 04, 2012:
Steam pressure, to drive turbine coupled to alternator.
Ashok shrestha on February 04, 2012:
Sir can we produce electricity by the help of pressure?
Dave McClure (author) from Worcester, UK on February 02, 2012:
That's the principle of the galvanic cell, but there's no way you get 10 volts from a single cell. You'd need a stack of cells for that.
Surendra Subedi on February 02, 2012:
if i connect two electrodes of different ionisation potential on the collected mass of rotten potatoes,then i got a dc of about 10 volts.then i got a lead of about 4 volts,which lit easily with the obtained voltage.
sridhar on January 16, 2012:
thanks to all
Saurav Singh on January 09, 2012:
now thats what i call a information which i never get from any whear else ... thanks for it ....
Dave McClure (author) from Worcester, UK on January 09, 2012:
Tesla & Nandan - glad it was useful.
Nandan on January 08, 2012:
it was awesome.... really a gud information about energy..actually im a civil engg student. somehow i got intrust in electrics... and now ua hub made it much more intrusting.. thanks a lot.
tesla follower on January 08, 2012:
this gives me so much info that i need. it really helps me understand something i love sooooo much better! thank you sooo much paraglider!!!!!!!!!!! :)
p.s.- i love energy science:)
Dave McClure (author) from Worcester, UK on January 06, 2012:
We won't run out of energy as long as the sun keeps shining and the winds and tides keep moving. We will run out of oil, but that's a completely different discussion, more political than anything else.
Future-generation on January 05, 2012:
That is a question I would like to know ! How can you conserve energy for in the future from when their might not be anymore energy ?
Dave McClure (author) from Worcester, UK on December 27, 2011:
markus - we won't run out of electrons. When you generate electricity, you cause the electrons to move in a circuit. They don't leave the circuit and are not created or destroyed.
markus on December 26, 2011:
could anyone explain me , suppose i have 1 light bulb , dissipates 1A/H. this current density is a flow of electrons of the resistor because of Voltage difference at its ends???(a)or is a flow of electrons also coming by powerhead lines?(b)if (a) or (b) is correct,will come a day that no more free electrons will exist to produce current, no matter if i have an endless water flow to move a generator continiously in the future??i would appreciate your comments
Jerrico Usher from Bend, Oregon on December 19, 2011:
Hi Paraglider, yea I never left, just stopped posting in the forum and got to writing (up to 724 woot woot). Thanks for bringing me up to date- the movie was a while ago and to be honest I remember some but not all of what was said- likely I jumbled that up lol... your a brilliant man- I love your explanations, very lucid. I think I understand it now.
Dave McClure (author) from Worcester, UK on December 18, 2011:
Hi Jerrico - I didn't realise you were still on HubPages. We used to chat quite a lot in the forums, 3 or 4 years ago. Now, I have to correct you on the AC/DC thing. Both AC and DC travel in copper cable at the same speed: two-thirds of the speed of light. The advantages of AC for distribution are: it is easy to step up (using a transformer) to very high voltages like 110,000 volts. At high voltages the same amount of power requires less current, and less current = less loss in the resistance of the cable. Also by generating and distributing 3-phase AC (and balancing the loads on each phase) the neutral return currents balance out, almost to zero in an ideal case.
DC distribution comes into its own only for extremely long distribution lines from power station to the users. I'm talking extremely long, like the Sahara or the Australian outback. In normal circumstances, AC is the better choice.
Jerrico Usher from Bend, Oregon on December 17, 2011:
Brilliant Hub, Very lucid explanation of electricity! Now where is that DC current hub you promised :) You peaked my curiosity- although I know how DC differs from AC I'm curious as to why one is fundamentally better than the other.
My current understanding is based on how electricity is distributed to homes i.e. DC would come in too fast and thus would be drained AND fry our electronics if not slowed or controlled- AC being essentially electricity flowing in then when not in use being directed back to the source for re-implementation (no loss or little loss).
I've not looked deeper into this than that (saw it on a movie about tesla and Einstein), I'd be very interrested in your hub about DC current as described in this hub (rather peaked at)...
Your writing is very lucid and interresting. You are amazing at taking a complex subject and turning it into a layman explanation- KUDOS- voted up
Dave McClure (author) from Worcester, UK on December 17, 2011:
Thanks for the Sliver Cell reference. It looks an interesting development. You know that when nuclear energy first appeared, people were predicting it would be free within a decade. It didn't happen though!
Dean on December 17, 2011:
Thank you for a wealth of knowledge that few have been able to provide.
I look forward to seeing what the green electric movement has to offer over the next few years, I'm especially keen to see what SLIVER cells by Origen energy have to offer.
I hope one day electricity can be free for all.
Dave McClure (author) from Worcester, UK on December 14, 2011:
OK, then back to the original question, no, I don't know of any source for such a device. Sounds an interesting project you're involved in.
James on December 14, 2011:
No not really, only due to the nature of fur covering and the possible damage due to fighting.
Dave McClure (author) from Worcester, UK on December 14, 2011:
Assuming the drain on the battery is low, I'm wondering if a small photovoltaic device might be an easier approach than a mechanical generator. Any good?
James on December 14, 2011:
Hi Paraglider, I am looking for someone that might produce the type of generator that would recharge a battery that would be on an animal so would be a type of pendulum. Do you happen to know of anyone that can produce this?
riverroad on December 05, 2011:
I should have stated the generated electricity is to heat water for space heating. I appreciate your hub and as my thoughts on this project progress may have some further questions. Thanks again
Dave McClure (author) from Worcester, UK on December 04, 2011:
Interesting project. Most water wheel systems don't sit directly on a river, but in a special channel like a traditional mill race. This gives control of flow and depth and helps the design of the wheel. If you used the electricity you generate for direct heating of water or space heating you could make some savings. But if you are thinking of sychronising the AC to the mains (50 or 60 Hz, depending where you live) with a view to returning power to the grid, you could be involved in some expensive technology.
riverroad on December 04, 2011:
I just moved next to a small river which flows @4 to 6 mph depending on river heights I would like to investigate using the current to operate a generator providing electricity for my property the depth of the river is @ 4 ft to 8 ft My thoughts have been a water wheel but I am very interested in hearing your thoughts on this and if it is a worth while endeavor,