SCI-184

STIRLING MOTOR

HISTORY & DEVELOPMENT

The Scottish religious Robert Stirling (1790-1878), invented this engine in 1816. Another important contribution in the development of the automotive machine handed the French genius Sadi Carnot (1796-1832), who was the first scientist to make a theoretical interpretation of the operation of heat engines, establishing the physical principles involved in their movement. This theory allowed us to understand more clearly the phenomenon that allows the Stirling produce motive force.

Originally conceived in 1816, was created by Robert Stirling as the first engine designed to rival the steam engine, due to high efficiency, if it is compared with steam engines, besides its easy to be applied to any source heat. That’s until the electric and internal combustion engines replaced Both at the turn of the 20th century. Stirling engines have only been used in very Specialized applications ever since, for example, in the 1960’s a tiny Stirling engine was developed to power an artificial heart and today They are Commonly used To provide the cooling for infrared guidance systems in missiles. However, With the Increased focus on Environmental Concerns and our quest for cleaner, more efficient power sources, the Stirling engine is back in the spotlight as a feasible power source for wide-scale use.

HOW IT WORK’S

The hot air Stirling engine uses a fixed heat source for heating air in your cylinder. It can be considered external combustion, as it requires no burn fuel therein and to operate, does not transfer heat to the environment. It’s movement is due to differences in air pressure between the warmer and cooler portion. The central mechanism of a Stirling consists of two pistons / cylinders, one for dissipating heat and displace warm air into the cold section (vice versa). In practice this cylinder functions as heat exchanger and is called regenerator. The other piston delivers power to apply torque to the crankshaft.

Every Stirling engine has a sealed cylinder with one part hot and the other cold. The working gas inside the engine (which is often air, helium, or hydrogen) is moved by a mechanism from the hot side to the cold side. When the gas is on the hot side it expands and pushes up on a piston. When it moves back to the cold side it contracts. The two piston type Stirling engine has two power pistons. The displacer type Stirling engine has one power piston and a displacer piston.

Displacer Type:
The displacer type Stirling engine is shown here. The space below the displacer piston is continuously heated by a heat source. The space above the displacer piston is continuously cooled. The displacer piston moves the air (displaces the air) from the hot side to the cold side. When the engine pressure reaches its maximum because of the motion of the
displacer, a power piston is pushed by the expanding gas adding energy to the crankshaft.

Two Piston Type:
The two piston type Stirling engine is shown here. The space above the hot piston is continuously heated by a heat source. The space above the cold piston is continuously cooled. But its during the expansion part of the cycle where the engine gets its power.

MODERN DAY USES

Military uses:
A Swedish army submarine is Equipped with Stirling engines for its auxiliary electrical production in order to Provide the vital functions in the event of unavailability of the main source. Its silence of operation is a major asset In this application. In the same context, the Australian navy ADOPTED Also have it for a 3000 tons displacement submarine.

Spatial domain:
Some satellites get energy through a Stirling engine. The efficiency is high Particularly Considering the great Differences in temperature. The hot source Consists of radioactive isotopes. The use of radioactive elements is not very ecological, it presents Risks at the time of the take-off of the rocket. The justification comes owe owing to the fact That solar panels can be dirtied or be destroyed in Un certain zones of space, as near Mars.

Domestic uses:
Small installations were developed in order to function in cogeneration: electricity supply and dwelling heating. One chooses fuel (oil, wood, wood pellets…) to make electricity and to heat a house. During certain periods, it is possible to sell excess electricity if one is connected to the grid.
Some pleasure boats are equipped like that.

Generators :
After the second world war, Philips developed and marketed the generator which group had a power of approximately 150 Watts.

Cryogénic domain :

The reversibility of the Stirling engine is used in order to produce cold in an industrial way. Its efficiency is then excellent. In this type of operation, described on this site in the page “Stirling coolers”, we provide mechanical energy to the engine. In fact, we transfer calories from the cold source the hot source, like in a domestic refrigerator. This mode of operation is so efficient that we use this type of installation to liquefy certain gas.

-Paradox : use sun for generating electricity by a Stirling engine, then this electricity drives a Stirling engine for making cold. How to make ice under a blazing sun, and all thanks to him!!

-At last i would like to show you this 10 top modern uses of a stearling motor as a curiosity, which i found to be pretty interesting:

Picture gotten from —>   http://www.discoverthis.com/article-stirling-engine-top10.html

WHAT’S FOR THE FUTURE?

A very promising use of Stirling engines is cogeneration, where they produce both heat and electricity for homes.  If the excess heat produced by Stirling engines was directly used to replace furnaces and water heaters in homes, this would yield a dramatic increase in energy efficiency.  This is especially useful for “off-grid” applications where people are too far from power plants to get electricity over cables.  Many companies are currently looking into using Stirling engines to replace the current systems in refrigerators.  Driven in reverse, Stirling machine pistons manipulate the contained gas to affect temperatures outside the machine. Stirling engines would use as much as 50% less electricity and even more importantly, they do not require CFCs for cooling.  One company, Global Cooling, has developed a solar-powered Stirling refrigerator that could be used in the developing world for keeping food and medicine cool.

Researchers at Los Alamos are currently working to design a Stirling engine that would cool the gas so that it becomes a liquid, which would make it much easier to transport in conventional pipelines.Their new engine uses intense acoustic energy instead of pistons for the heat transfer.  Constructed of welded pipes, the engine is remarkably simple, efficient, and inexpensive.

Perhaps the greatest challenge facing Stirling engines is the popularity of internal combustion engines.  Designers of Stirling engines will need to offer incredible advantages to be able to attract manufacturers aways from gasoline engines. In addition, new materials need to be developed for the hot parts of the engine; this is the part that is most likely to wear out. Once they are mass produced, the cost of Stirling engines will come down greatly and their popularity should increase.

PELTIER DEVICE

PELTIER HISTORY

Early 19th century scientists, Thomas Seebeck and Jean Peltier, first discovered the phenomena that are the basis for today’s  thermoelectric industry :

-Seebeck found that if you placed a temperature gradient across the junctions of two dissimilar conductors, electrical current would flow.
-Peltier, on the other hand, learned that passing current through two dissimilar electrical conductors, caused heat to be either emitted or absorbed at the junction of the materials.

It was only after mid-20th Century advancements in semiconductor technology, however, that practical applications for thermoelectric devices became feasible. With modern techniques, we can now produce thermoelectric “modules” that deliver efficient solid state heat-pumping for both cooling and heating; many of these units can also be used to generate DC power at reduced efficiency. New and often elegant uses for thermoelectrics continue to be developed each day.

PELTIER STRUCTURE

Looking at the figure, we can see that practically two semiconductor materials, include one with and one with N channel P channel, linked together by a copper foil.
If in the N side of the material feeding the positive polarity on the side of the material P the negative polarity is applied, the copper plate cools the top while the bottom heat.
If in the same cell, the power supply polarity is reversed, that is, applied on the side of the material N negative polarity and on the side of P positive material function heating / cooling is reversed top heated and the lower cooling. It is, therefore, static heat pump that requires neither gas nor moving parts. Physically a Peltier element module 1 mm cubic blocks are connected electrically in series and thermally in parallel.Today, they are solidly constructed and have the size of a quater. Semiconductors are made ​​for Tellurium and Bismuth type P or N (good conductors of electricity and heat) which facilitate the transfer of heat from cold to hot by the effect of a direct current side.

PELTIER THEORY

When DC voltage is applied to the module, the positive and negative charge carriers in the pellet array absorb heat energy from one substrate surface and release it to the substrate at the opposite side. The surface where heat energy is absorbed becomes cold; the opposite surface where heat energy is released, becomes hot. Reversing the polarity will result in reversed hot and cold sides.

CURRENT DAY USES OF THE PEILTER DEVICE 

-Currently, one of its most common uses is as part of the CPU cooling computers.

-Board control Refrigerator: the Peltier module for cooling booths telecommunications network and dashboards within the factories are used.

–Small sump constant temperature: In the experiments of culturing microorganisms is required to control the temperature near the body temperature and the ambient temperature. The precise temperature control near ambient temperature with cold hampers or heating facilities, the best thing is the Peltier module.

-Milk cooling: Recently established machines coffee and soft drinks are, with increasing free sites beverage services in different types of restaurants. This machine coffee service has put a milk cooler wearing a Peltier module. It may take 2-4 packs of 1 liter milk and keep it cold.

-In the field of air conditioning there are air conditioning equipment that control temperature and humidity equipped with compression refrigerators which use refrigerant fluids based on compounds of fluorine and chlorine in greater or lesser extent that attack the ozone layer.

-They have also developed air dehumidification equipment employing chemical absorbers and compression equipment generally of large dehumidifier power.The presented technology involves passing aire from a room , residence, etc.., Drawn by a fan through some cold packs, which are cooled by Peltier effect, collecting the condensed water in the system at a lower tray. It is very suitable for controlling moisture in humid climates, which eliminate noise and vibration, avoiding the moving parts of the compressor that carry current dehumidifiers and refrigerants, as potential environmental contamination compact

Problems related to Peltier cooling

-The power usage and high power dissipation are the biggest problems related to peltier cooling. In the days of first-generation Pentium CPUs, readymade peltier/heatsink combinations were widely available, which could be installed and used just like a regular heatsink. For today’s CPUs having a power dissipation of over 100W, building a Peltier CPU cooler using just a peltier element and a heatsink is quite a challenge, and ready-made peltier coolers are scarce and expensive. With such coolers, over 200W of heat may be dissipated inside the case. The resulting cooling system will be expensive to run, due to its high power usage, and not very eco-friendly. The large power dissipation will require powerful (and thus loud) fans.

-Also, keep in mind that if the cooling of the peltier element fails (e.g. fan failure or pump failure in case of watercooling), the results will be more disasterous that if a conventional cooling system fails. Even if your CPU has a thermal protection that will cause it to shut down if the temperature gets too high, the peltier element may still kill it by continueing to heat it up long after it has shut itself down.

-Another problem related to peltier cooling is condensation. Since it is possible to cool components below ambient temperature using peltier elements, condensation may occur, which is something you’ll definitely want to avoid – water and electronics don’t mix well. The exact temperature at which condensation occurs depends on ambient temperature and on air humidity

Advantages of Peltier elements

-After having focused on problems related to Peltier cooling, let’s not forget about their biggest advantage: They allow cooling below ambient temperature, but unlike other cooling systems that allow this (vapor phase refrigeration), they are less expensive and more compact.Peltier elements are solid-state devices with no moving parts; they are extremely reliable and do not require any maintainance.

—-SOURCES—

www.stirlingengine.com

en.wikipedia.org

www.stirlingshop.com

www.heatsink-guide.com

Geothermal energy

Energy that can be obtained by utilizing the heat from inside the Earth.
The term “geothermal” comes from the Greek geo (‘Earth’) and thermos (‘heat’), literally ‘heat of the Earth’.
This internal heat warms up the deeper water layers: at the rise, of the hot water or steam  produce manifestations such as geysers or hot springs,
used for heating since the time of the Romans. Today, advances in drilling and pumping methods allow to exploit geothermal energy in many parts of the world.

It can be considered that there are two types of geothermal reservoirs, which could be called:
-Hot water
-Dry

Hot Water Reservoir

The forming fountains, have been take advantage of since ancient times as hot springs. Initially they could be used to cool the water before use, but they often have relatively low flow rates.
As for the one’s underground, reservoirs of very hot thermal waters anywhere from little to average depth, serve to capture the heat from inside the earth. The hot water or steam  can flow naturally pumped or pulsed flow of water and steam.In most cases the operation must be made with two wells (or a pair number of wells), so that one obtains the hot water and the other is re-injected into the aquifer, having cooled the flow obtained.

Dry Deposits

In this case, there is an area underground, not too deep, with dry, hot materials or stones . Water is injected by a perforation and recovered, on the other hot, the heat is used, by means of a heat exchanger and is re-injected as previously mentioned.

-ICELAND-

Is a country located in the northeast corner of Europe.Its population is estimated at 320,000. The great grace of Iceland is that given the wide range of natural resources, an about 94% of its energy comes from renewable sources (mainly hydro and geothermal).

Iceland sits on one of the world’s greatest geothermal hot spots and a recent discovery of underground Lava has Increased the amount of geothermal energy harnessing the country could be. Iceland gets 94 percent already of its electricity from the renewable resource, and expects to be fully powered by renewable energy by 2050.

In 1940, 85% of Iceland’s energy came from coal and oil. Now 85% of the energy comes from underground volcanic water (geothermal source). Iceland currently has the largest geothermal heating system in the world, and other countries are interested. With most of its energy needs met, and having it been a success on the generation of clean energy, Iceland has made countries like the UK interested in buying this type of energy from them.

A few months ago both negotiated the construction of an underwater cable that would pump through almost 1500 kilometers geothermal energy from Iceland to the UK. Such a cord will not be cheap to build, but in the long run, Iceland would have a really nice source of revenue and Europe would not have an abundant source of clean energy.

The giant undersea cable is being proposed by Landsvirkjun, Iceland’s biggest energy company. If built, the cable would be between 1000 and 1600 kilometers long and export 5.000.000.000 de kWh of power each year. That’s between $350 million and $448 million worth of energy–enough to cover the consumption of 1.25 million homes, according to the AFP. Currently, Iceland’s economy is largely dependent on fishing. But if it is completed, the undersea cable could trigger the growth of a major new economic sector in Iceland: exported energy. With a growing demand for clean power across Europe and the rest of the world, that could make Iceland’s resources a hot commodity.

Iceland’s Biggest Plant-

It’s the Hellisheidi geothermal plant, the newest built in Iceland which has an installed capacity of 303 MWe (electrical) and 130 MWt (thermal) capacity. Iceland has an installed capacity of 665 MW – geothermal energy – so only this plant, accounts for almost half of total installed capacity. Here you may see a wonderful diagram, with the operations of each of the constituent elements, or by accessing the following link, you’ll be able to see and interactive as well as descriptive virtual tour of all its components

www.or.is/vinnsluras/

SOURCES-

www.sciencedaily.com

www.ecogeek.org

www.fastcompany.com

INTRODUCTION TO SOLAR ENERGY PHOTOVOLTAIC 

Solar Energy is the energy gained by capturing the light and heat emitted by the  sun. The solar radiation that reaches Earth can be exploited through the heat  produced, as well as through the absorption of radiation. It is a so-called renewable energy particularly of Group contaminant, known as clean energy or green energy.

-The Photovoltaic Effect-
Is the basis of the process by which a PV cell converts sunlight into electricity. Sunlight is composed of photons, or energy particles. For PV cells convert the light energy into electrical energy. Performance  conversion, (the proportion of solar cell converted from light into electricity) is fundamental in the photovoltaic devices, since the increase in performance makes the PV solar energy more competitive with other sources.

-Solar Energy-
Emblem of renewable energy has noticed a progression in recent years due to improvements in technology, with associated cost reduction mainly thanks to the interest shown by the different administrations in different countries, in form of grants or subsidies .

– Situation in the European Union-

Installed in the EU area is concentrated in three countries Germany 5,442,000 m2, Greece and Austria with 2.877 million m2 2,711,000 m2. Germany is the leading installer of photovoltaic energy in the world, with a capacity of more than 32.3 gigawatts from December 2012. The new German solar PV installations grew by about 7.6 GW in 2012, about 3% of total electricity. Some market analysts expect this could reach 25 percent by 2050. Germany has a goal of producing 35% of electricity from renewable sources by 2020 and 100% by 2050.

– Situation in North America-

The United States has considerable solar activity and many solar power plants on a commercial scale . The largest solar power installation in the world is the Solar Energy Generating Systems facility in California , which has a total capacity of 354 megawatts. There are plans to build other large solar plants in the United States. Gov. Jerry Brown signed legislation requiring California utilities to obtain 33 percent of its electricity from renewable energy sources by the end of 2020.

The Canadian PV market has grown rapidly and Canadian companies make solar modules, controls, specialized water pumps, refrigerators, high-efficiency solar lighting systems. Ontario has subsidized solar power to promote its growth. One of the most important uses of photovoltaic cells is in northern communities, many of which rely on high-cost diesel fuel to generate electricity. Since the 1970s , the federal government and industry has promoted the development of solar technologies for these communities. Some of these efforts have focused on the use of hybrid systems that provide power 24 hours a day, using solar power when sunlight is available, in combination with other energy source.

– Situation in Africa-

On average, many African countries receive up to 325 days of sunshine a year. This gives solar power the potential to bring energy to virtually any location in Africa without the need for expensive large scale grid infrastructure developments. The distribution of solar resources in Africa is fairly uniform, with more than 80 percent of the African landscape that receives almost 2,000 kWh per square meter per year. A recent study indicates that an installation of solar power generation covering only 0.3% of the area in North Africa, could supply all the energy required by the European Union.

– Situation in Latin America-

During the past decade, Latin America has stood for notable increase. The market fell somewhat by the crisis in Asia, but was assisted by experiencing an explosive growth in the telecommunications area. Revenue from solar energy are increased in an average of 15 to 20 percent.

The major consumers of photovoltaic equipment in the world in their process of  development are in Mexico and Brazil, which contribute to the growth of solar energy in Latin America. Mexico is already the largest producer of solar energy in Latin America and is planning a ground-based solar collector with 30 MW, which will use a gas turbine combined cycle of approximately 400 MW to power the city of Agua Prieta, Sonora . To date, the World Bank has given U.S. $ 50 million to fund this project.

– Situation in Asia-

China generates about 7 GW of power , with the recent announcements that they’ll target an additional 10 GW of power in 2013-14 with a target of 21GW of power in late 2015.

India is densely populated and has high solar radiation, which makes it ideal for the use of solar energy. In the field of solar energy, they have proposed some major projects: a 35,000 km2 area of the Thar Desert has been earmarked for solar power projects, sufficient to generate from 700 GW to 2100 GW. In July 2009, India unveiled a $ 19 million plan to produce 20 GW of solar power by 2020. Under the plan, the use of solar energy equipment and applications have been made mandatory in all government buildings, as well as hospitals and hotels. In November 18, 2009, it was reported that India was ready to launch its National Solar Mission under the National Action Plan on Climate Change , with plans to generate 1,000 MW of power.

Solar power in Japan has been increasing since the late 1990s. The country ‘s leading manufacturer of solar panels and is ranked on the top 5 countries with the most installed solar PV , the third largest worldwide in total solar energy.

-The Price Of Panels Around The World-

Chinese manufacturers such as Suntech have overtaken other global distributors of solar panels in recent years. Suntech has produced over 1000 MW as of this year, and Chinese solar panel manufacturing has increased to 4000 MW as a whole. Half of the world’s largest solar manufacturing companies are based in China now. This is due to the relentless price cutting of solar panels. Chinese manufacturers can make these for just $1.28 per watt, compared to the lowest Western supplier’s price of $2 per watt.

In India, the price of solar panels dropped by around 50 per cent in 2011, making them more cost effective for people than diesel. With many homes using diesel generators to cope with frequent blackouts on the national grid, renewable affordable energy could soon be the more common answer. Solar electricity is getting cheaper, and analysts predict that it will be as cheap as grid electricity by 2015 in half the countries of the world.

-SOURCES-

en.wikipedia.org

www.nytimes.com

www.planetsave.com

So this week’s in class activity had to do with the relationship between: Force, Mass and Acceleration.    

This new activity came along with a new set up, an a slight difference on the robot. This time the robot was composed by  the LEGO mindstrom motor, a pulley and a set of weights.

(New robot set up)

-NEWTOWN’S 2nd LAW- 

Provides a relationship between the unbalanced force on the object, the mass of the object and the acceleration that is produced:

unbalanced force = mass x acceleration (F = ma).

-We fisrt had to explore Newstowns 2nd law by keeping the power level fixed and changing the mass.

• Does the acceleration vary with mass?

What both me and my partner discover was that by keeping the force (power) at a constant level and only changing the mass of the object been picked up acceleration did change, and it change in a negative relation with the mass been applied. For example whe started with the lowest weight on our first run, and then increased it with the other try’s, and  the hevier the mass the less acceleration it produced with the same amount of force (power).

(We can notice here in the graph how the acceleration is reducing from our first run, till the third one)

-We then had to keep the mass fixed and change the power level. 

• Does the acceleration vary with power level?

In this second part of the activity we found out how by keeping the mass steady, not changing it, and just increasing the force (power) of the LEGO motor the acceleration here would change with a positive relatonship with the change of the force being incremented. For example: we kept a steady mass of 0.1 kg, and started with a force of 25 increasing each run by double. By doing this we realized that everytime we incremented the weigth, in this case from 25 to 50 on the second run, we realized that the acceleration also incremented by two, this case from 250 to 500 on the second run.

(We can see here how the force being increased with a constant mass, the acceleration increased too)

By the end of this activity we had realized that there are two points to note about there are two points to note about the acceleration of an object when an unbalanced force acts on it:

-The bigger the unbalanced force acting on the object the bigger the acceleration of the object.
-The more mass the object has the more inclined it is to resist any change in its motion.

For example,
If you apply the same unbalanced force to a mass of 1000 kg and a mass of 1 kg, the acceleration (change in motion) of the 1000 kg mass will be much less than that of the 1 kg mass.

Climate scientists agree that climate change increases the likelihood of stronger and wetter storms. However, researchers were unable to say just how responsible climate change was for the development of Sandy .Climate scientists avoid blaming any single weather event  on global warming but many say that climate change may well have played an important role in the destruction caused by Sandy.

Hurricane Sandy’s storm surge was elevated by both the warming sea-level rise and the timing of the lunar cycle. Sandy occurred during the astronomical high tide (2 to 3 inches above a normal high tide). Global sea level has already increased by 4 inches since 1950, creating the equivalent of a fulltime high tide.Sandy carried an unusual amount of moisture, which increased the risk of very heavy precipitation within its path. Much of the warming from climate change occurs in the ocean. Sandy spent significant time over uncommon warm sea level’s boosting the amount of moisture available to drain down.

Hurricane Sandy was encountered in a “traffic jam” in the North Atlantic, known as a “block” to meteorologists. This block did not allow Sandy to track out to sea like most northeast storms. Meanwhile, a storm associated with some very cold air over the Midwest also ran into this Atlantic traffic jam, resulting in an unusual “hybrid” storm.

Finally, Sandy also carried an unusual amount of moisture, which increased the risk of very heavy precipitation within its path. Much of the warming from climate change occurs in the ocean.

(NASA  animation of the jet stream that shows how, over time, the south and north waves of the jet stream have grown deeper and move more slowly across the middle latitudes, as melting sea ice warms the arctic).

Hurricane Sandy brings us to conclusion two mayor corncerns : We need to reduce the risks of climate change by reducing our carbon emissions, and we must strengthen our defenses against future impacts that it may be too late to avoid. Our sea walls and other infrastructure were built to deal with the extreme weather risks of the 20th century.  Sandy is offering an opportunity to see where we fall short in preparations for the 21st century.

SOURCES-

A Year After Sandy, Living Dangerously by the Sea

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

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

http://www.pbs.org/wgbh/nova/earth/climate-change-sandy.html

Approching my first hands on class activity, i didnt know how thsis little robot would turn out to be. As we recived the robot, group-mates starting setteling together, wire up left, batterry under attached, wire  to the rigth, etc and i was pretty lost at this point, good thing my class-mates took a second and stopped and explained me how it work, and what had been going on on the last class.

As for the first robotic’s activity we had in class, they told me how they had to build it up, putting its wheels, the cables, etc. And how after that, they had to program it so they could start trying it out and start learning how to use it. Not much i can say from this part due to my absence, but to point out how by looking and examening the robot i came to the conclusion it must had been something peculiar to do , atlest for me… Since i had never though Lego would actually be in a university’s science class , maybe im just some what of and ignorate but it seems pretty cool to think you where once playing with them in your house and your now doing research hand’s-on activity’s!!!!!

For this second part of the activity we were ask to measure the distance the car traveled, applying diferrent speeds and seconds for duration.To do this we had both a ruler for our own data copilation and the computer program, which send’s and recive’s the robot’s power, time of travel, and distance thru and usb cable you plug in. As we worked our self’s thru the first 2 trials we noticed that our first errors where pretty big staying above the 2/3 ratio, and decided to apply a longer run time with a small decrease on power, and taraaaa!! we had done it, the error came down around half of what it was.

This activity was great, there’s nothing better than getting your hand on something and testing it yourself, specially if its with LEGOSS!!! hahahah

-Just for thouse of you who’s curiosity has been triggered by this amazing lego robot cars, here are a couple i have found and i find pretty cool ….

1.Hands Free Flusher

This LEGO Mindstorm Robotic Toilet Flush System is a very polite robot that thanks you after you use the toilet and then flushes it for you.

2. Rubic’s cube Genious

GENERATORS-
The electrical energy is produced in devices called generators or alternators.

A generator consists, in its simplest form:

-A rotating coil driven by some external media.
-A uniform magnetic field created by a magnet, within which the previous loop tour.

As the loop rotates, the Magnetic drive through flow changes with time, inducing an electromotive force, and if there is an external circuit, an electric current will flow. For a generator to work, you need an external source of energy (hydro, thermal, nuclear, etc..) To make the coil turn at a desired frequency.

-NUCLEAR PLANTS-

A nuclear power plant is a thermal power station. The fundamental difference between nuclear power plants and conventional thermal energy resides in the source used. In the first, uranium and in the latter, the energy of fossil fuels.
A nuclear power plant is, therefore, a power plant in which the  boiler acts as a nuclear reactor. The thermal energy is caused by the fission reactions in the nuclear fuel comprising uranium compound.

Nuclear fission is a process by which the nuclei of certain heavy chemical elements break down into two fragments by the impact of a particle (neutron), releasing a large amount of energy that is obtained in the  nuclear plant, water vapor.

-COIL & NATURAL GAS  PLANTS-

-Electricity Generation By Source-

Coal

Coal is the predominant fuel used for electricity generation worldwide. In 2010, coal-fired generation accounted for 40 percent of overall worldwide electricity generation. Coal-fired electricity generation grows in the Reference case at a 1.8-percent annual rate from 2010 to 2040. In 2040, total world electricity generation from coal is 73 percent higher than the 2010 level.

Natural gas

In 2010, natural gas accounted for 22 percent of the world’s electricity generation. Its projected share rises to 24 percent in 2040. Prospects for natural gas have improved substantially over the past several years. Low natural gas prices are having an impact on the diversity of the fuel mix used in electricity generation. In the near term, the diversity of the fuel mix is increasing as fuel-switching from coal to natural gas proceeds; however, in the long term, a sustained low natural gas price may discourage investment in nuclear generation and renewables. Policy is necessary to ensure that the percentage of zero carbon-emission power generation is growing sufficiently to mitigate the most dangerous effects of climate change.

Nuclear Power

Electricity generation from nuclear power worldwide increases from 2,620 billion kilowatthours in 2010 to 5,492 billion kilowatthours in 2040 in the IEO2013 Reference case, as concerns about energy security and greenhouse gas emissions support the development of new nuclear generating capacity. In addition, world average capacity utilization rates have generally risen over time, from about 68 percent in 1980 to about 80 percent in 2011. Factors underlying theIEO2013 nuclear power projections include the consequences of the March 2011 disaster at Fukushima Daiichi, Japan; planned retirements of nuclear capacity in OECD Europe under current policies; and continued strong growth of nuclear power in non-OECD Asia.

SOURCES:

http://en.wikipedia.org/wiki/Fossil-fuel_power_station

http://www.eia.gov/forecasts/ieo/electricity.cfm

http://www.c2es.org/publications/leveraging-natural-gas-reduce-greenhouse-gas-emissions#iv_power_sector

Germany’s renewable energy sector is among the most innovative and successful worldwide. The share of electricity produced from renewable energy in Germany has increased from 6.3 percent of the national total in 2000, to 25 percent of 2012. In 2010, investments totaling 26 billion euros were made in Germany’s renewable energies sector. Germany has been called “the world’s first major renewable energy economy”.

Renewable energy technologies were part of a broader long-term German energy strategy to reduce greenhouse gas emissions and other environmental impacts of energy use, to curtail dependence on the oil and gas imports that now satisfy some 62% of German energy demand, and to contribute to German economic growth via high technology exports.

Germany’s renewable energy producers enjoy a guaranteed minimum price for their energy. So they can produce and sell it at a guaranteed price, no matter what customers want, which has led to somewhat of an energy bubble in Germany. Many Individual’s are producing green energy no one actually needs, but are entitled to sell it. In the end consumers have to pay for it. These policies caused the price for energy to double over ten years.

This incentives are soo, that there’s often way too much energy in the power grid, that german energy providers actually have to pay other countries’ grid operators to accept their energy in order to take pressure off the German grid. Czech Republic and France are some of the countries that have to take Germany’s energy, especially when it is very windy or sunny as windmills and solar panels are very productive on those days.

Centralized electric generating plants with local distribution networks were started in the 1880s and the grid of interconnected transmission lines was started in the 1920s. Today, we have a complex patchwork system of regional and local power plants, power lines and transformers that have widely varying ages, conditions, and capacities.

Over the years, the network has been a successful source of energy for the nation. The electric grid delivers electricity thru millions of miles of transmission lines.  The network itself is composed of smaller networks: Eastern Interconnection, Western Interconnection and Texas Interconnection, a connected system of power plants and transformers, by more than 450,000 miles of transmissions lines. First, the power is created in power plants and sub-stations then sent through the transmission lines. Then, a smaller, local system of low-voltage transmission lines deliver it to each individual customer.

The age of the equipment explains some of the failures that lead to frequent failures in power quality and availability. During the past decade, electric energy infrastructure has improved through an upturn in investment. We need to look into more investments in order to decrease disruptions in service ,due to having components that have different age, capacity, and conditions, as well as meet the demands of our rapidly growing population and it’s demands for energy.

Apart of the equipment age, some people talk about the idea of a smart grid to improve the system. For a century, companies have had to send workers out to gather much of the data needed to provide electricity. Most of the devices utilities use to deliver electricity have yet to be automated and computerized. Now, many advances are being made available to the electricity industry to modernize it.Much in the way that a “smart” phone these days means a phone with a computer in it, smart grid means “computerizing” the electric utility grid.

Now, the Department of Homeland Security, recognizes that today’s quality of life depends on the continuous functioning of the nation’s electric power infrastructure, which if computerized, could be at risk from malicious cyber attacks. These risks may come from cyber hackers who gain access to control networks or create denial of service attacks on the networks themselves, or from accidental causes, such as natural disasters or operator errors.

Soo, which one is the solution what should we do about it ? computerize it or not? Well, its evident that both of the options (leving it as it is, or modernizing it) would have errors, or some type of risk against it, wether by hackers or natural forces. Well i am no expert on the field, i dont know much about if modernizing it, would benefit us more or just make it vulnerable to cyber attacks,but i do know that the power grid is becoming threatened as people are searching for their own ways to create electricity. Companies such as google and apple have begun to develop solar farms to get their electricity. Verizon is spending $100 million to power offices and call centers via solar panels and fuel cells. Hospitals, universities, and other big companies are rapidly installing fuel cells that get electricity through a chemical reaction. Clearly, if the power grid does not undergo major change, the US will find other ways of getting more reliable and cheaper electricity as the demand for it grows.

  SOURCES-

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

http://www.asce.org/Infrastructure/Failure-to-Act/Electricity-Infrastructure-Report-Executive-Summary/

http://tcipg.org/about-tcipg-trustworthy-cyber-infrastructure-power-grid