Coal Power

 Otto E. Eckert Station in Lansing.  Taken with a Hasselblad 500C using Ilford SFX film, and a red filter.

The story of coal starts hundreds of millions of years ago when the climate and geology allowed for vast peat bogs or swamps to cover large areas.  Roots from pants, plants or animals that died and were covered by the water which prevented the remains from decomposing and a thick layer of dark organic material forms.  Over time the climate changes, and the swamps become buried deep in the earth, which compressed and cooked the layer of organic material into coal over millions of years.  This is why the coal is not considered to be renewable; it takes millions of years to form we are using it much faster than it can be replenished.

Left; Michigan State Coal Power plant in Lansing Michigan.  Taken with a Hasselblad 500C using TMAX 100 film and a red filter.

In ancient times, easily accessible coal deposits were used for various purposes, but it wasn't until the 1700s that coal was used on a large scale for smelting iron.  By the 1800s more and more factories had adopted the use of coal power since it freed them from the geographical restrictions, and coal gas lighting was used to keep the factories running all night [NPR].  Basically, coal fueled the industrial revolution and made the world a smaller place by powering steam engines used in ships, locomotives, mining operations and eventually to generate electricity. 

A coal plant is fairly simple. Coal is pulverized into a powder, then blown into a boiler and burned.  The reason the coal is pulverized into a fine dust is so that it will burn more like a gas and therefore will burn faster and more efficiently.  The heat generated by the burning of the coal powder boils water, which creates steam, that steam turns a turbine, that turns a generator that produces power.  Here is a diagram from the Canadian Clean Power Coalition website that is pretty detailed.

 

Click here to see the website that has a fuller explanation.

In the United States, approximately half the electricity used is from coal power [Clean Coal Coalition].  Of course this can vary from states to state.  For instance 60% of Michigan's electricity is produced from coal, where California's power portfolio is only about 1% coal, and is comprised mostly of natural gas and hydroelectric. 

Despite the growing concern over global warming, and the fear that human sources of green house gasses might be a primary cause, coal is still a major source for generating electricity in the US.  Coal is cheap and abundant in the US, and the general public believes the plants are safe and cheap when compare to alternatives like nuclear, natural gas, or petroleum.  Since there are large coal deposits in the US, it reduces the need to import energy sources from foreign governments.  Also, people perceive coal to be a safe technology in that a coal power plant doesn't have the potential to explode and destroy a whole community.  

Though coal is very cheap, the technology is safe, these tremendous benefits are offset by tremendous drawbacks since the burning of coal releases huge amounts of pollution into the air, and the worst pollutants aren't the greenhouse gases.  According to the Union of Concerned Scientists, a typical coal power plant emits (1) 3.7 million tons of CO2, (2) 10,000 tons of sulfur dioxide (SO2) that is responsible for the acid rain that damages forests and lungs, (3) 500 tons of small airborne particulates that cause bronchitis, aggravated asthma and premature death, (4) 10,000 tons of nitrogen oxide that can damage the lungs, (5) 170 pounds of mercury that contaminate water and make fish unsafe to eat, (6) 225 pounds of arsenic that can cause cancer.  So coal is a lot more deadly than just its potential to cause climate change it is a very real and current health risk to people and the environment residing around a power plant.

My personal opinion is that coal is bad now, but new emerging technologies promise to make black coal green.  Currently the clean coal technology is either all experimental or cost prohibitive, but coal is predictable, not as geographically dependent as hydro power, and there are large coal reserves all over the US.  In future articles, I will be exploring some of these new technologies.


Advantages:
-Abundant supply, help reduce dependence on foreign sources of energy
-Inexpensive, though the cost varies by location, it typically costs about a third of other sources
-Relatively safe, low risk of catastrophic accident

Disadvantages:
-Generates vast amounts of pollution



Formation of Coal from the University of Kentucky website.

Union of Concerned Scientists

Nuclear Power

Control Room Simulator for Cook Nuclear Power Plant, Michigan

One aspect of nuclear power that I find interesting is that there are people who love nuclear because they believe that this source is environmentally friendly and practical, and there are those who are vehemently opposed to nuclear because they feel very strongly that nuclear is dangerous to local communities and the waste is excessively harmful to the environment.  To be fair, I should share my personal bias; I like nuclear power for a few reasons; its safer than people know, it does not produce any air pollution, its relatively in-expensive to operate, the fuel is plentiful, and most importantly its proven technology that we are taking advantage of now.  Fusion may be the holy grail of electrical generation, but it won't be viable for decades, if ever, and we have to address our energy needs now while balancing national security, public health and environmental concerns.  As I have said before, nuclear has benefits and drawbacks, and the huge drawback with nuclear is the management of very dangerous waste products.  Since I am not terribly concerned with a reactor going critical and exploding, or otherwise causing a catastrophe, the real question is does the prospect of having to manage highly radioactive waste for a very long period of time out weight the drawbacks of fossil fuel burning plants?  Depending on how a community, country, or the world answers that question will determine how the future of nuclear power.

How Nuclear Reactor Works
As strange as this may sound, a nuclear power plant is fundamentally a cousin of the coal, or natural gas plant in that the water is heated to create steam, which turns a turbine that spins a generator that produces electricity.  A radioactive substance, in commercial reactors that fuel is uranium, creates heat as the atoms break down, and vast amounts of heat is generated.  So the operation of a nuclear reactor is basic in concept since all that is required is to gather a sufficient quantity of nuclear fuel, submerge it in water, and use the steam to produce power.  Of course, in practice it is not that simple for when nuclear fuel is amassed, the radioactivity feeds off itself and starts a chain reaction that has the potential to perpetuate it self uncontrollably and that is when the reactor has the potential to explode or melt down.  However, a reactor works more efficiently if the reaction does not have to be stimulated

Let me explain, in a little more detail how the reactor actually works.  Uranium is radioactive, which means that it is inherently unstable.  Eventually, given its instability, a uranium will decay or break apart.  In nuclear reactors, the fuel is enriched with an isotope of uranium that will decay when struck with a neutron, and in turn throws off two or three more neutrons.  Now what makes a nuclear reactor work is that those two or three neutrons will likely trike two or three uranium atoms, which will in turn each decay releasing heat and two or three neutrons each potentially releasing up to 9 neutrons.  If those 9 neutrons hit 9 uranium atoms, then 27 neutrons could be released, and so on and so on.  Or, in other words, this is the start of a chain reaction.  If this reaction continues without abatement, then the fuel will start to get very hot, melt, and the the reactor could melt down.

Chain Reaction Video:




Uranium fuel is formed into pellets that are about the size of the end of a grown mans pinky finger.  These pellets are arranged in long stacks within a metal tube called fuel rods.  A fuel rod may be as long as 12 feet, and they batched together to form an assembly.  A typical fuel assembly is arranged into 8x8, 14x14, 17x17 blocks of fuel rod.  These assemblies are placed into the reactor core in a manner that balances safety and efficiency, and intermixed with the fuel are control rods that can slow or even stop the reaction. Control rods are made up of a material, such as cadmium, that is very good at capturing neutrons, and if you remember the sequence of atoms decaying, releasing neutrons that strike other uranium atoms causing them to decay and release more neutrons.  If those free neutrons are stopped, then the chain reaction is slowed or stopped. 

Reactor design does vary from plant to plant or country to country, but the basic design for capturing the heat energy released as a uranium atom decays is for the whole reactor core to be contained within a large stainless steel vessel filled with water similar in many respects to a large boiler.  This water is able to circulate through the fuel assemblies where is gets heated.  The heated water either its self becomes steam (see Boiling Water Reactor, abbreviated BWR) or is used to make steam (see Pressurized Water Reactor, abbreviated PWR).  Like a coal or natural gas plant, the steam then turns a turbine that turns a generator.

Picture of the reactor vessel from EIA (Energy Information Administration).  This is from a PWR (Pressurized Water Reactor)

Water is circulated through the reactor vessel and used to generate steam.  One safety feature of a nuclear reactor is the water that is passed through the reactor and nuclear fuel is isolated from the water that becomes steam and passes through the turbine.  Often, a power plant will have three separate water loops, a primary that cools the reactor, a secondary that is heated by the primary loop to become steam, and a tertiary loop that is used to convert the steam back into water.  Typically the tertiary loop is drawn from an environmental source such as a river, lake, or ocean.  The diagram below from the Tennessee Valley Authority (TVA) illustrates the multiple loops, the primary loop is pinkish, the secondary is blue and goes to the turbine, and the tertiary loop (in this diagram) goes to the cooling tower.

http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml

Wind Power - A summary

 Picture was taken at the Michigan Wind 1 Farm up in Huron County Michigan.  This farm consists of 46 GE 1.5 MW turbines and is owned and operated by the John Deere Renewables LLC.

We have been harvesting the wind for energy for thousands of years, from sailing ships, to windmills, the next logical step was to use this seemingly endless source to generate electricity, even if it isn’t very predictable. For those who might not be aware of it, wind is basically another form of solar energy. Heat from the sun warms the air which becomes less dense and rises. Air that had risen will be displaced by more rising air, cool, and sink back down. This rising and sinking forms a convection current, and it is this movement of air that creates wind. Now, the trick to being able to convert wind into electricity is to be able to change the linear motion of air into rotational motion that can be used to turn a generator.

To be fair to my readers I must say that I am a little partial to the idea of wind energy, especially when considering the aesthetics. Having visited Michigan Wind 1, I think these tall spinning structures are very cool looking.  However, like all sources, this is not a perfect solution to our energy needs, and I may represent a small minority who actually like the way these new wind turbines look. Many also complain that they kill birds and bats, and can cause health issues for those living within close proximity.

As for the visual impact of a wind farm on the landscape, this is a purely subjective criterion and would be an issue that individual communities would have to address before a wind farm is installed. I am not trying to minimize people’s feelings about the visual impact a wind farm would have, but this may be an issue for some communities and not for others.  I am sure that someone in Martha's Vineyard will be less willing to see a wind farm installed off the coast. 

Common complaints raised by those who are not fans of this new technology sometimes refer to these machines as bird and bat "cuisinarts." I have done some investigation into these claims to see where this data is derived from and how accurate these claims are. It turns out that this complaint is based on bird mortality rates from a few studies at the Altamont Pass Wind Farm near San Francisco California in the 1980s. Numerous factors, including the design of the turbines, the towers, and the location contribute to the high mortality rate of raptors, but this is not the norm. More recent studies at newer generating sites that have larger turbines and more current designs have an extremely low mortality rate, especially when compared to bird deaths by other human activities. A commonly referenced study is one written by Robert W. Howe, William Evans, and Amy T. Wolf in 2002 covering a two year period between 1999-2001, and was focused on 31 commercial turbines in Wisconsin. Their finds suggest that 1.25 birds are killed annually by each tower which was close to the national average of 2.19 birds per turbine. When compared to how many birds are killed by cars, buildings (100million - 1 billion/yrs, the studies are on going), communication towers, feral cats (estimated to be at least 8 million/yr in Wisconsin alone), electrical transmission wires (estimated at 130-174 million per year), and pesticides (69 million per year are killed directly, an unknown number indirectly); these numbers are extremely low. The same was found to be true for bats as well. Though some bats do die, this is has been attributed to migrating bats that are thought to fly without using their famous sonar in order to conserve energy for the migration.

Unfortunately, it does seem that wind turbines in close proximity to a residence can induce certain health affects, usually related to lack of sleep. Dr. Nina Pierpoint, an adamant opponent to wind technology has written a book, and has a web site detailing an illness she has termed “Wind Turbine Syndrome.” I cannot vouch for her research, but I can say that there are documented complaints from residents who live near large wind farms. For instance, residents living near Michigan Wind 1 located up in the “thumb” of Michigan near the city of Ubly (where I have taken the pictures for this article) are not necessarily excited about having this farm in their back yards. In a Mlive article posted June 11th of 2009, journalist Jeff Kart talks to some residents who complain of sleepless nights and other disturbances due to the close proximity of the turbines. Dr. Pierpoints website has a number of articles from around the world indicating that this is not an isolated problem.  Some have suggested that those who are complaining are doing so because they are not benefiting financially from having the turbines near by. At this point, its hard to say, but I will be looking into this more and more.

At this point I am not going to cover shadow flicker, which is the health affects brought on by the shadow cast by the blades as they spin.  The health affects associated with shadow flicker, and just the spinning of the blades can cause vertigo, dizziness, nausea and the like. 

One technological hurdle that needs to be addressed is due to the inconsistent nature of wind.  The turbines cannot produce power on a predetermined schedule as with a conventional plant such as coal, nuclear or natural gas. Currently, the grid system cannot efficiently respond to the unpredictable quality of wind. A fundamental rule of the electrical grid system is that electricity must be used as it is generated and it cannot be stored. Given the large volumes of electricity that is consumed in the US, a wind farm can’t simply come online for a short irregular intervals because that would mean another generating facility would have to respond by ramping up or down to match the rate at which electricity is produced with the rate at which it is being used. This is one reason why our aging infrastructure needs to be updated is to make it “smarter” to blend the current large generating plants with these new renewable sources whose power is unpredictable.

Of course the benefits of wind power are that it is a renewable source of power that produces no greenhouse gases, harmful air pollutants or other long term waste. Also, wind has the potential to be very cheap. Depending on the location, the type of the turbine, and the wind speed, the cost of electrical generation from a wind farm can be competitive with current nonrenewable sources. The AWEA (American Wind Energy Association) has quoted the production of wind energy to be less than five cents per kilowatt hour when the Production Tax Credit is considered in the price. Compare this to 20-30 cents per kwh for solar, and this makes wind a very attractive renewable energy source. To give you a benchmark, coal can cost anywhere from 4-10 cents per kwh depending on location of plant and the source of the coal, but I think it is safe to assume that the cost per kilo watt hour is closer to 4 cents on average.  


Advantages:
-Emits no air pollution while operating
- Relatively safe (in high wind speeds they can disintegrate violently)
-Cheap source of renewable energy

Disadvantages:
-Wind is not predictable
-To be affective, turbines need to be placed in specific locations
-May cause health affects to residents within 2 mile radius of large turbines

Fusion – A Look at the Future

The picture to the left is of the University of Michigan's Laser Chamber - considered to be one of the most intense lasers in the world. The red beam is NOT the laser it's self, its a sighting laser used to aim the main laser. This is an infrared laser that is being illuminated by a phosphorescent card. It may be hard to see, but the reason the laser seems to be tapering toward the left is because it is being focused at a specific point.

For many decades the promise of fusion power has been dangling like a carrot and vowing endless, safe, clean power. Each year it seems like the day that we will actually realize this dream keeps getting pushed back further and further. But, honestly, I don’t really know anything about how a fusion reactor might operate, what waste, if any, it may produce, or when we might see these plants in operation. However, I do know someone who can answer some of these questions and so I sat down with my friend Chris McGuffey to discuss the future of fusion. Chris is working toward a PhD in Nuclear Engineering at the University of Michigan, in Ann Arbor.  Michigan has one of the best nuclear engineering graduate programs in the US (here), and the laser my friend is working with as part of his research is lauded to be the most intense laser in the world (2008). His research is focused on the physics of lasers and particle beams, or as he puts it; “Specifically I work to create electron beams and x-ray beams which may be substantially cheaper than those produced by conventional accelerators. Additionally the same physical mechanisms are important in the "fast ignition" and "direct drive" schemes of inertial confinement fusion.”

Through my discussion with Chris, I can present you a vision of the future:
Let me transport you 50 years into the future (assuming the world doesn’t end in 2012) to the opening of one of the first commercial fusion reactors. Imagine a thick walled stainless steel chamber that is spherical in shape and ten meters (or think 10 yards for the metric challenged) in diameter. Pointed at the center of this sphere, where the fusion reaction is taking place, are a number of instruments, and lasers. The reaction is fed by a steady stream of fuel pellets that are about as large as the head of a pin and are being fired into the center of the reactor at 5-10 times per second. As each pellet is zipping into the chamber, lasers lock onto the pellet applying light pressure and heat to initiate a burn.  When the pellet reaches the center of the chamber, an extremely powerful and amazingly short burst from the lasers will have heated it enough that the fusion reaction will begin. What is being termed a “burn” is not the traditional burn, like how wood burns; this burn is two isotopes of hydrogen being fused together to form an alpha particle (a helium atom without any electrons) and one neutron, and then perpetuating this reaction throughout the fuel pellet. The heat that is produced when the atoms fuse is not what will be used to produce electricity.  Instead you have one fast neutron that will shoot off into a fluid that is laced with the isotope lithium-7. When the neutron interacts with the lithium, another reaction occurs. In this reaction, the fast neutron combines with the lithium and causes it to split into one tritium, one helium, and a slow neutron as well as creating heat (Nave, 2006). The heat will be used to create steam to turn a turbine that will be used to generate electricity.

Portals to view into the laser chamber.

However, this vision of the future makes a few assumptions; one, we have developed materials or processes that will be able to survive the constant bombardment of high energy neutrons for a reasonable, and economical amount of time; two, we will be able to capture the energy efficiently. Lastly, can we capture more energy than it takes to ignite the reaction. Probably, one question that should be asked and some people may not be asking is: is this worth it? I, for one, have been led to believe that fusion is this holy grail for the power industry, and promises to be clean, safe and to have unlimited power potential since the fuel is the most abundant element in the universe: hydrogen. Call me a cynic, but I want to know what the catch is. Nothing is free, and nothing is so easy, so I have been wondering if fusion is as clean and safe as I have been led to believe.  Well, I thought it was a good question and that is what I hoped to glean from my discussion with Chris.  His answer was a little unexpected; fusion is safe, is clean and has the potential to be everything that is promises.  Since the process is not like a chain reaction in a fission reaction where we have to be constantly reigning it in, there is no possibility of a catastrophic event; like a nuclear explosion or melt down.  Also, since the fuel is hydrogen, and all the necessary containment is relatively light material - lighter than uranium, so any radioactivity produced will be short lived.  When Chris was referring to short lived, he did not mean short on a geological time scale, he meant short on the human scale. So the waste, can be managed in our life times, and in a hundred years or less the waste will be safe.  Also, it will not be as "hot" as the waste produced by current fission reactors that is also very long lived.  Think tens if not hundreds of thousands of years.  As for environmental impact, the fusion reactor will produce as many green house gases as a conventional nuclear power plant.  What I mean by that, is that the reactors largest contribution of green house gases will likely have to do with its construction and not its operation.  The heavy equipment to forge, move, and build the reactor will burn fossil fuels (presumably) that would otherwise not be burned.  So then if this is so great what is the hold up?  Research.  The technology required to commission the first reactor is so daunting, and expensive.  The impression I got from Chris was that 50 years may be a some what optimistic time line.  Specifically, we will need to have some vast improvements in materials to make this dream a reality.

There are two main reactor designs emerging from research and development programs, one is the Inertial Confinement Fusion (ICF) design that I had illustrated above. High power lasers are used to initiate the fusion reaction by applying intense amounts of heat and pressure. When I say pressure, the pressure is indirectly applied by the lasers.  They heat a little vessel that the fuel pellet will be contained in.  As the vessel is heated to incredible temperatures in extremely small fractions of a second (think 1x10^-9 to 1x10^-14 seconds) the vessel will explode inward, and compress the fuel.  The second design uses magnetic force to squeeze the atoms together to initiate the fusion reaction, and is referred to as Magnetic Confinement Fusion (MCF). The International Thermonuclear Experimental Reactor (ITER) project is building a MCF test reactor in Cadarache, France that is expected to run for 30 years. Construction is beginning and is expected to be finished in 2018, followed by 20 years of experimentation.

Above is some of the gear used in the laser lab.

In regards to ICF, there are two major projects in the world. One is the National Ignition Facility (NIF) located at the Lawrence Livermore National Lab in Livermore California. This facility is expected to be the first to achieve “ignition” – meaning that the reaction will produce more power than it consumes. France has also started a project called the Laser Megajoule that will deliver 1.8 million joules of power to the targets and will help to study the physics of the heat and pressures that exist in the center of the sun. 

Currently, the biggest hurdle to building a successful commercial reactor is developing materials that will survive the harsh environment in the reactor chamber. High energy neutrons are shooting out and smashing into the walls of the reactor. As the neutrons strike the walls of the reactor they are damaging the micro structure of the material and will eventually fatigue the steel to such a degree that the reactor vessel will have to be retired. Even though neutrons are very penetrating, and damaging they can be stopped with lead shielding fairly easily.

To the right is a gray wall of duct tape wrapped lead bricks used to shield the lab from powerful X-ray radiation emitted when the particle beam created by the laser passes through the stainless steel walls of the laser chamber.

This is just an introductory article on fusion, I expect to write many more that will delve into more detail as this blog evolves over time.  But just a recap, below are some of the advantages and disadvantages of fusion as far as can be determined at this time.

Disadvantages:
-Not currently a working option
-Very expensive R&D required to have functioning reactor design
-Likely to be very expensive to build the reactors
-Many unknowns

Advantages:
- Cheap, abundant fuel
- No greenhouse gases are produced
- Short-lived, manageable radioactive waste
- No chance of catastrophic explosion or melt-down

I would like to say thank you to Chris McGuffey for taking the time to sit down with me and talk about lasers, fusion and for letting me take the above pictures in the lab.

Energy 101: 02 - The Grid

No doubt, this is one of the most overlooked elements of the entire electric system by both the general public and utility providers alike despite the fact that the power lines are usually the most visible aspect of the power industry.  Most people would consider the grid as being nothing more complex than running wire from a power plant to the various customers and maybe this is partially why it is almost ignored except when the power goes out.  As for the utilities, the transmission lines aren't actually generating revenue like a power plant would.  So it can be easy to see how a utility company would prefer to maintain, and invest in power generation instead of upgrading power lines and other grid elements. 

Above is the substation at the natural gas plant in Morro Bay CA.  Just Past the substation, you can see the the large transmission line towers, and more towers carrying the transmission lines off over the hills.

So what is "the Grid"? 

The power grid is the power lines and associated equipment that forms an interconnected network of suppliers and customers.  This definition does not accurately portray the complexity of the system nor does it express how improving the grid can reduce energy consumption, improve electricity quality and reliability.  One complicating aspect of the electri grid is that electricity cannot be stored in sufficient quantities to meet demand, which means that electricity must be produced at the same rate that is it consumed.    This means that utilities must be accurately predicting demand, and have some excess capacity available for sudden spikes in demand. 

How it works:

Power is generated at a supplier such as a coal plant, a wind turbine, or such. To most efficiently transport that electricity, voltage is increased or “stepped up.”  For instance, the voltage coming out of the steam generator at a coal power plant may be 33,000 volts (abbreviated as 33 KV, where kV = kilo-Volts), and a transformer in an on site sub station will bump up that voltage to 500,000 - 750,000 volts (abbreviated 750 kV). Transmission lines carry this electricity over long distances to various customers.  Some industrial customers may need high voltage, so they will have their own substation that will be tapped directly into the transmission lines and this substation will reduce the voltage to whatever the customer requires. This reduction in voltage is called “stepping down.”

Different cities, communities and residences may have different electrical needs, so how the power gets from the transmission lines to a house may not necessarily follow these steps in every instance, but it’s a good approximation of the process.  High voltage transmission lines will feed a step down substation that will take the 500 – 750 kV and reduce the voltage to 69 kV.  A distribution substation, which is a substation close to a residential neighborhood, will take the 69 KV and step that down to 2,400-19,000 volts that can service a comerical building or small industrial customers.  However, this is still way to high of a voltage for a residential home, so somewhere near the house, usually on a telephone pole, there is one more transformer that is usually described as a garbage can that steps the power down to 110/240V used in the home. 


Different Elements of the Grid: 

Transmission lines:  As mentioned earlier, are high voltage power lines that are transmitting electricity over long distances.  The farther the electricity is traveling the higher the voltage is used to prevent loss, typically 500kV to 750kV.  In 2002, there were 157,810 miles of transmission lines stitched across the US.  Some of you may have noticed that transmission lines have three or six wires.  This is because the electricity is generated in three phases (which is explained in the fundamentals of electricity article), and each wire is carrying a different phase.

Distribution Lines:  These are lower voltage lines that are feeding customers.  These are the ones you would see in the neighborhood around your house and would be the ones that are 2400 volts - 19000 volts.  An example of a distribution power line can be seen to the right.  The metal cylinder on this power pole is a transformer that will step the power down to what the customer requires. 


Substation:  A substation can fill many roles.  Typically its main function is to step voltage up or down and to protect the grid from power failures by isolating sections with the uses of switches.  In 2004, there were 10,287 transmission substations and 2179 distribution stations within the North American power grid.  


Transmission Loss

When electrons flow through a conductor (aka a power line or wire), the metal has some resistance to the flow of these electrons.  Like friction in a mechanical device, this resistance converts energy, in this case electrical energy, into heat.  The more electrons that flow the more that are lost when passed through the conductor.  There are several ways that this loss can be mitigated.  One way is to reduce the amount of current (current = electrons) that is transmitted across the power line by reduce the current and increasing the voltage.  That is why long distance power lines are also very high voltage, since the higher the voltage the less current needs to travel.  Other possible solutions, which aren't as economically feasible, would be to increase the size of the power lines, use new materials that are more conductive, and/or to use more power lines. 





The NPR website has a great map of the North American grid here.



Reference Links:
http://www.npr.org/templates/story/story.php?storyId=110997398

http://sites.energetics.com/gridworks/pdfs/factsheet.pdf
http://arxiv.org/PS_cache/cond-mat/pdf/0401/0401084v1.pdf
http://sites.energetics.com/gridworks/index.html
http://tonto.eia.doe.gov/energyexplained/?featureclicked=2&

Energy 101: 01 - Types of Energy Sources

I plan to organize this blog around the various types of energy sources, so it might be best to define and describe how we produce energy and transmit that power to the consumers.  Firstly the sources are broken into two major categories; nonrenewable and renewable.

The image to the left is the Trenton Power plant in Detroit Michigan.  A 776 Mega Watt (MW) capacity power plant that has three units, the first of which was built in 1949.

Nonrenewable Energy Sources:  These are created by slow geological process and/or have a finite quantity on the earth.  For instance, oil or coal is created in such a slow process, it will take millions of years to create more.  Uranium is a nonrenewable source because there is only a finite amount of this element on the earth, and there is no natural process on the earth that will replenish this source.  In the US coal is the most common fuel source for generating electricity(49.8% according to the DOE), this is mainly because there are extremely large coal deposits in the US and this is a cheap fuel source. 

List of Nonrenewable resources:
Oil
Coal
Natural Gas
Propane
Other Fossil Fuels
Nuclear (Uranium)

To the right are five wind turbines located near the town of Elkton Michigan.  There are a total of 32 wind turbines with a combined capacity of 53 MW.  


Renewable Energy Sources:  Renewable energy is replenished at the same rate or faster than they are used, so they are effectively limitless.  Most all of these sources derive their energy from the sun in some way or another, the only exception to this is geothermal.  For electrical power generation, hydro power is by far the most common.  When considering all types of energy (heat energy for instance) biomass is the most common renewable energy source.

List of Renewable Energy Sources:
Wind
Solar
Biomass
Bio-Fuels
Hydro (water, such as from dams)
Geothermal
Tidal


My future articles will explain how these various sources are utilized to generate electrical energy and how it is distributed via "the grid."