First, I would say that the film was inserting to watch. It can actually makes you think deeply about how our future will be. Watching the film I think it is completely one sided. I was really disappointed to see almost no coverage of any interviews with experts about energy efficiency or renewable energy. For example, solar panels and wind turbine, when these are the cleanest, fastest and cheapest solutions to climate change. Furthermore, in the United State the utilities have tripled their investment in energy efficiency in the last two years. That’s making all of our homes, shops, and businesses get more energy services out of the power that we generate. Although, the film clearly says that alternative solutions like solar panels and wind turbine is not a real energy solution. The film also says that those alternative solutions will never going to be enough and that’s why oil companies invest in it and support it because they know it will never be a real solution.  From reading a lot of articles about Pandora’s Promise, that’s is not what people who are expert in the areas of renewable energy would say. The Natural Resources Defense believe that renewable’s wind turbine and solar panels energy efficiency alone could be 80% of the population needs by 2050 in the United State.

Some people will not agree with Natural Resources Defense because by doing the math, the reality is that renewable energies, non-hydro renewables, are less than 2% of global energy and the growth in global energy use is 2 to 3% a year. Meaning that 20 to 30 years of subsidies to renewable energies are supplying one year’s growth. From this information the population have to move forward. The people need abundant, affordable, and clean energy without cutting off any of those sources. One of those sources is also Nuclear power energy. Nuclear should be one of the options. The people, who favor nuclear don’t object solar panels or wind turbines. I have heard some people who favor Nuclear energy, but also cover their houses with solar panels. They can generate twice as much energy of their usage, but the problem is renewable energy advocates will first have to try to cut down nuclear energy so that the people have no choice. However, I do agree on both of the discussion I talked about on those two paragraphs. Acknowledging that I may not believe the Natural Resources Defense’s math on the renewable energy efficiency.

Being interested in the environment before and during this science class; I have found that leadership of the environmental movement does not support nuclear energy. Knowing that the dictator of the film was before opposed to nuclear energy. His first documentary was an anti-nuclear documentary. His last documentary was loving the history of the environment movement, but he had an over whelming support for the proposition to take his new film further. From this information we know that he got a lot of support to open to the world the benefits of nuclear power.

Friday march the 11th at 2:46 pm an exceptionally powerful earthquake hit the pacific coast of Honshu the main island of Japan at 3:36 pm, less than an hour after the earthquake a tsunami swept over the coast; the waves went all the way up to 10 kilometers in land. Results over 20,000 people dead, or missing, destroyed towns, ports, and land devastated. Nuclear power plants were also affected and one in particular namely the Fukushima Daishi. Fukushima Daishi is 250 kilometers northeast of Tokyo; the Nuclear power plant has six rectors. Each reactors’ successively commissioned during the nineteen seventies. Unit 1, 2, and 3 were operating at full power, the core in unit 4 was unloaded. Unit 5 and 6 were in cold shutdown.

Fukushima reactors have a different technology than the pressurized water reactors built by the French operator EDF, they are boiling water reactors called BWR, and it is called a rector because the heat in the core is produced by fission reactions. Boiling water because the water that removes the heat from the core turns into steam and the steam goes directly to the turbine. The turbine drives a generator that produces electricity. Afterwards, the steam is condensed with the help of the seawater cooling system and returns to the core. A boiling water reactor has only one single system combining feed water and steam. The core is composed of fuel assemblies containing uranium; control rods introduced from the bottom that can stop the fission reactions in case of an emergency. Fission as uranium nuclei produces radioactive atoms that in turn produces heat and this continues to occur even after rector shutdown, this is called residual heat; keeping the fuel confined and cooled is a major safety issue. The fuel was isolated from the environment by different containment barriers jut like the famous Russian dolls. A first barrier the fuel cladding of zirconium alloy, a second barrier the steel reactor vessel in combination with steam and water cooling systems, finally the third barrier the containment building in concrete leait tight steel liner. The fuel is kept under water in the reactor as well as in the adjacent pool where the spent fuel isn’t loaded. The pool is located at the top of the reactor vessel to facilitate the transfer fuel underwater.

When the earthquake hit the coast, seismic sensors triggered the insertion of control rods, although fission reactions stooped; the residual heat had to be removed. The offsite power supply was lost and the emergency diesel generators took over automatically, they supply electricity to the backup system needed for poor cooling. In reactors 2 and 3, it is a turbo pump and the steam generated by the reactor operates the terrible palm, which feeds water into the reactor vessel. The steam in condensed in the wet well suppression pool within the containment. In reactor 1, there was no turbo pump, but a heat exchanger, which condense steam from the reactor vessel. The condensed water was reintroduced into the reactor vessel by gravity. This heat exchanger provide core cooling by natural convection for more the 10 hours; until then everything seemed under control. However, reactors 1 due to excessive cooling force the operators to temporarily isolate the heat exchanger in compliance with operating procedures.

The tsunami wave arrived less then an hour after the earthquake. The waves went over the seawall, flooding the lower part of buildings and disabled the emergency diesel generators. On reactor 1, the operator was unable to reactivate the heat exchanger, the core was no longer cooled, and it would be the first to melt. On unit 2 and 3, the batteries were still operational, they operated sum of the valves. The turbine driven pumps ran for nearly 24 hours and then stopped and the course were no longer cooled. The meltdown scenario is almost the same with all three reactors, only the dates were different. The water in the reactor vessel evaporated and the fuel become uncovered and heated up to a temperature of 2300 degree Celsius causing the fuel to melt and be mixed with the materials from the structure to from a magma called corium. The corium flowed down to the bottom of the reactor vessel. According to Japanese officials say, it pierced the reactor vessel before falling on the concrete basement inside the containment.

What quantity of corium fell? How deep did it a root the concrete? Did it pierce the steel liner? Even today it is not possible to learn more about the state of the corium in the three reactors. At the same time the reactor vessel’s steam was loaded with radioactive elements in hydrogen. As the steam pressure rose to a dangerous level in the reactor vessel the depressurizing vessel opened and the gas was forced into the web wall suppression pool by inventing line. The water acted as an phishing filter by trapping much of the radioactive element, but the water was no longer cold because the emergency diesel generator were out of order and it soon began to boil there by reducing its filtration capacity. The web well suppression pool in the communicating containment begin to enter into an over pressure situation to avoid containment rupture the operator decided to release the gas into the atmosphere, normally the venting line should have led all the gas outside the building, but hydrogen was escaping through uncontrolled leakage pathways and it was released into the reactor building. Hydrogen reacts violently with oxygen in the air; the explosion blew apart the frame and apparently without damaging the containment building; radioactive elements were released into the environment. Due to the absence of usable freshwater on the site, the operators decided to inject seawater into the reactor vessel. In addition, since salt is chemically active had at least the advantage of cooling in stabilizing the corian.

In the four days following the tsunami, explosions damaged the four reactors and three of them with core melt. Although is has kept its structure intact, reactor 2 is the current source of the most important radioactive releases into the soil as well as into the sea. The explosion took place inside the building; operators have probably encountered difficulties depressurizing the containment and the wet wall suppression pool broke. The explosion on reactor 4 was due to hydrogen even though the core was completely unloaded. The hydrogen came from reactor 3 via a joint pipe. The reactor’s storage pools were also in a great concern because they have lost their cooling system. In addition, they were not protected by any containment.

Gradually this situation began to stabilize, by the end of March 2011; freshwater had replaced seawater. In July the reactor cooling system was again in operation in closed circuit. Thereby, avoiding discharges of contaminated water into the environment. In December 2011, Japanese authorities officially declared that the nuclear power plant reached the cold shut down state; an expression used when cooling water does not evaporate anymore and remains liquid below 100 degree Celsius.

Men working under extremely difficult conditions managed this nuclear crisis. They were cut off from the rest of the world, with no news from their families after the tsunami, without any power supply, threatened by radiation; they fought with all their force to cool the reactors and trying to make in vain the backup system work again.

(This figure describes the six reactors in Fukushima from the inside)

Sources: 

– https://www.wikipedia.org

– http://www.naturalnews.com/Fukushima.html

– http://www.greenpeace.org/international/en/publications/Campaign-reports/Nuclear-reports/Lessons-from-Fukushima/

– http://news.nationalgeographic.com/news/energy/2013/08/130807-fukushima-radioactive-water-leak/b

Lego Robot#5

The fifth and sadly the last robot experiment we had, was very interesting. I am an electrical engineering student that wants to specialize in the power filed. Knowing that our last experiment using the Lego robot was about solar panels. Moreover, this lab explains how can the population produce power by using the sun and especially without harming the environment.

Equipment:

–       one solar cell

–       one voltage probe

–       one NXT adaptor

–       NXT with light sensor

–       One light sourse

–       Labview VI  solarlab1.vi

–       Ruler

–       Colored film filters

–       Excel sheet

Procedure:

After the instructor reviewed to the class what this labs assignment is, which is calculating the output voltage from a single solar cell, so that the students will be able to understand how to use the equipment to measure the voltage output of the solar cell and the light intensity output of the light sensor of the NXT.

After m partner and I have understood how the VI works, we erfomed several experiments to try to gain an understanding of the relationship btween the light intensity and the voltage output of the solar cell, my partner and I have also understood the relationship between the wavelength of the light and the voltage output of the solar cell.

While we were taking our measurements we had to vary the distance between the solar cell and the light source; to actually comprehend the different of the voltage output.

Data:

Figure 1

As you can see in figure 1 in the first row it shows you the different filters that was used to do the experiment, knowing that their was a part of this experiment that did not use flitters not light source. In figure 1, you can actually see on the last test that my partner and I have not used the light source to we can see if there is any voltage being produced from the solar cell, but as you can see it was a very low voltage output and it maybe from the light of the classroom. This table shows us that adding filters to the solar cell can affect the output voltage, but with out using any filters you can produce a large voltage from it.

Figure 2

In figure 2 you can see the relationship of the light source with the filter. From the graph it is obvious to see that with out any filters the output voltage is higher than with filters.

Conclusion:

It was a fun lab overall, it took a lot of time for my partner and I to complete it with all the filters that was required be used five time, but by the end of the class we did. I have learned a lot in this lab experiment, in which how the solar panel works and how much output is being produced from it

The fourth experiment using Lego robot was to generate voltage by shaking the generator by hand! Voltage can be described as the electric potential difference between two points; another name for voltage is (Electric potential difference).  It was very interesting lab to actually see how a single person can generate voltage just by applying force on the object. For example, People can generate electricity just by biking; this force will transfer to get an electricity output from it. Moreover, the primary purpose of this experiment was to see how voltage can be produced by people’s energy and the fun part is to see which group in class are the strongest to produce more voltage.

In this experiment my partner and I have set all the equipments and the programs that will be calculating our voltage output. First we were assigned to do the experiment five times and notice the difference between them when changing the numbers of shakes. Knowing that it will be tiring to do (Ha ha!) Noor (My partner) decided that we should take turns so we can have fun and be tired equally. We had a long talk about the last turn, nobody wants to do it. The second assignment was to add in all the data to excel and show the slop of the number of shakes versus the output voltage.

Data and Graph:

 Figure 1:

In figure one, it shows the number of shakes that were generated by my partner and I, the output voltage data calculated by Matlab, and finally the sum of all the output voltage From the graph we can notice that when there were no shakes on the generator there was barley an output voltage, but by the time we increased the number of shakes the output voltage increases tremendously, depending also how strong you are! This relationship is directly proportional.

Figure two: (Two pats):

In figure two, it shows us the relationship between the numbers of shake and the sum of the voltage for each shake column.

Iceland is well known to be a world leader in the use of geothermal district heating. After the second World War, Orkustofnun carried out research and development, which has led to the use of geothermal resources for heating of households. Today, about 9/10 households are heated with geothermal energy. Space heating is the largest component in the direct use of geothermal energy in Iceland. The figure here on the right gives a breakdown of the utilization of geothermal energy for 2011. In the year 2011, the total use of geothermal energy was 42,2 PJ, with space heating accounting for 45%.

Generating electricity with geothermal energy has increased significantly in recent years. As a result of a rapid expansion in Iceland’s energy intensive industry, the demand for electricity has increased considerably. Iceland is a pioneer in the use of geothermal energy for space heating. Generating electricity with geothermal energy has increased significantly in recent years. Geothermal power facilities currently generate 25% of the country’s total electricity production.

Often considered the model of geothermal development, Iceland continues to grow its

geothermal portfolio. With a small population, the country is currently generating 100% of its  power from renewable sources, deriving 25% of its electricity and 90% of its heating from geothermal resources.142 Seven geothermal power plants have been constructed in Iceland (six are currently operational) representing 575 MW of an estimated 4,255 MW of installable capacity.143 According to a recently released Iceland Geothermal Energy Market Report, “geothermal power projects represent the majority of planned capacity, or 1,068 MW of a total of 1,658 MW” planned energy capacity installations.144

The installed generation capacity of geothermal power plants  totaled  661 MW_e in 2012 and the production was 4,600 GWh, or 24.5% of the country’s total electricity production.

.Recent Geothermal Development Highlights

Icelandic geothermal producers Hitaveita Sudurnesja and Orkuveita Reykjavikur signed an agreement with Century Aluminum Co. to supply 250 MW geothermal electricity for aluminum production. The project, which will be commissioned in 2010, can be expanded to up to 435 MW. The IGA notes in its 2005-2010 Update Report that “this will be a very efficient way of exporting the surplus of cheap and abundant geothermal electricity production from Iceland.”145 ▪230 MW geothermal capacity is currently under construction.146

sources:

• http://www.nea.is/geothermal/
• http://www.renewableenergyworld.com/rea/blog/post/2013/03/geothermal-energy-in-iceland-too-much-of-a-good-thing
• http://www.islandsbanki.is/english/industry-focus/sustainable-energy/research-and-publications/

Stirling Engine

Stirling engine is a simple, practical heat engine using a gas as working substance. Stirling engine contains a fixed amount of gas which is transferred back and forth between a “cold” and a “hot” end of a long cylinder. The “displacer piston” moves the gas between the two ends and the “power piston” changes the internal volume as the gas expands and contracts.

The gases used inside a Stirling engine never leave the engine. There are no exhaust valves that vent high-pressure gasses, as in a gasoline or diesel engine, and there are no explosions taking place. Because of this, Stirling engines are very quiet. The Stirling cycle uses an external heat source, which could be anything from gasoline to solar energy to the heat produced by decaying plants.

A Stirling engine uses the Stirling cycle,­ which is unlike the cycles used in internal-combustion engines.

• The gasses used inside a Stirling engine never leave the engine. There are no exhaust valves that vent high-pressure gasses, as in a gasoline or diesel engine, and there are no explosions taking place. Because of this, Stirling engines are very quiet.
• The Stirling cycle uses an external heat source, which could be anything from gasoline to solar energy to the heat produced by decaying plants. No combustion takes place inside the cylinders of the engine.

Stirling Engine Aplications:

• Stirling engines are used in some very specialized applications  where quiet operation is important like in submarines & auxiliary power generators

• Stirling Engines are extensively used in Solar Power Generation
• Stirling engines also works in reverse as a heat pump & find its’ applications as Stirling cryocoolers
• There is a potential for nuclear-powered Stirling engines in electric power generation plants
• Stirling engines are often used in automotive applications even though Stirling Engines have too low a power/weight ratio and too long a starting time.

Sources:

• http://auto.howstuffworks.com/stirling-engine.htm
• http://stirlingshop.com/html/applications_.html
• http://www.bekkoame.ne.jp/~khirata/academic/kiriki/begin/general.htm.

Peltier effect

The Peltier effect is a temperature difference created by applying a voltage between two electrodes connected to a sample of semiconductor material. This phenomenon can be useful when it is necessary to transfer heat from one medium to another on a small scale.

See the figure below:

In a Peltier-effect device, the electrodes are typically made of a metal with excellent electrical conductivity. The semiconductor material between the electrodes creates two junctions between dissimilar materials, which, in turn, creates a pair of thermocouplevoltage   is applied to the electrodes to force electrical  current   through the semiconductor, thermal energy flows in the direction of the charge   carriers.

Aopplication:

• Peltier-effect devices are extensively used in refrigeration applications.
• These kinds of devices are used in semiconductor technology
• Peltier-effect devices are used in Instrumentation to change skin temeperature raidly

Sources:

• http://www.huimao.com/about/show.php?lang=en&id=4
• http://www.eng.fsu.edu/~dommelen/quantum/style_a/semicte.html
• http://www.sciencedirect.com/science/article/pii/0361923084902272

The current world leader in solar power generation is Germany. Two years ago the solar power plants were recorded as generating over 20 gigawatts of electric power per hour. Last year that number increased to nearly 24 gigawatts. To put this in perspective, it would take nearly 20 nuclear power plants at maximum output to equal this amount of power generation. Germany is in the process of replacing nuclear power plants with renewable sources of energy including solar power. This is not without controversy, however, since the photovoltaic cells required in these plants are currently much more expensive than the materials needed for more traditional power generating plants. Germany has placed itself in the global spotlight by directly scoffing critics that say solar power cannot produce enough electricity to meet the needs of an entire country. While there is no plan to generate all of Germany’s electricity needs through solar power, they are certainly generating a significant amount. Interestingly enough, there are some critics that say too much solar power generation could flood the grid and cause storage problems for the country.

Running a distant second behind Germany is Spain. An example of the size of these solar power plants can be seen in the side-by-side arrays located at the solar power plant in Seville. The smaller array has 624 mirrors that focus sunlight toward a 40 story tower. The heat from the focused sunlight is used to convert water into steam, which turns a turbine that feeds a generator and makes electricity. The larger array has 1255 of these mirrors. The goal for the site was to power 180,000 homes with the electricity generated from these two arrays by the end of 2013. Similar to the problems Germany is seeing, it is currently more expensive to generate power in this method than the more traditional methods of coal-burning, natural gas and nuclear power. The budding industry is confident that as the technology continues to improve the cost will continue to drop.

The country that generates the third largest amount of electricity from solar power is Japan. Not surprisingly, Japan has taken huge and speedy steps away from nuclear power generation after the Fukushima disaster in 2011. Accomplishments in terrestrial solar power generation aside, one Japanese company hopes to construct a solar power generating plant on the moon. Even though construction of the megalithic project is not scheduled for another twenty years, it is still garnering quite a bit of attention. Two immediate advantages to having solar power plants that are outside the Earth is that they can generate power continually without any interference or other complications from the atmosphere. The proposal is to use robots to mine material from the lunar surface to build mirrors which will line the Moon’s equator. The energy collected at the moon will be beamed back to the Earth in the form of microwaves and collected at various stations in the Earth’s oceans. A lofty plan indeed, but not entirely outside the realm of possibility.

The last country to make the list is the number four producer of electricity from solar power. This is the United States of America. Currently there are several solar projects in either the developmental or planning stages across the United States. Some of the states that are planning these projects are Arizona, California, and Colorado. These projects are each estimated to supply 100,000 homes with electricity. Unfortunately, just like in Spain and Germany, the cost associated with solar power is higher than desired. Research into photovoltaic cells is actively being examined by the United States government, not to mention several other institutions including the Massachusetts Institute of Technology. Perhaps this is where the United States can contribute to the global move toward solar powered energy

Source:

http://1bog.org/blog/top-10-countries-using-solar-power/

http://www.reuters.com/article/2012/05/26/us-climate-germany-solar-idUSBRE84P0FI20120526

http://www.amusingplanet.com/2013/08/the-solar-power-towers-of-seville-spain.html

http://qz.com/152384/japans-plan-to-supply-all-the-worlds-energy-from-a-giant-solar-power-plant-on-the-moon/

http://energy.gov/articles/5-super-sized-solar-projects-transforming-clean-energy-landscape

There are several methods that can be used to generate electricity. All of them have similarities and differences between them. The purpose of this blog is to outline three processes that are used to generate electricity, including how they work and some of their advantages and disadvantages.

The first process for examination is a coal-fired plant. The coal is used to generate heat which in turn is used to convert liquid water to steam. Because of this it is desirable to obtain the most heat from the coal as possible. This is accomplished by converting the coal into a very fine powder and burning it while it is suspended in very hot, dry air. This ensures that there will be total combustion of the coal and a maximum amount of heat will be produced. This heat is used to convert purified water into steam under very high temperatures and pressures which is then fed into turbines. As the steam passes through a system of giant turbines, the pressure causes them to rotate. Each turbine is connected to a generator consisting magnets that spin inside coils of wire, which in turn induce an electric current within the wires.

Equally important is the process by which the steam is returned to water so that it may be used again. A nearby river or lake is used to bring in cool water that aids in condensing the steam back to liquid water. The condensed steam can then be sent back to the plant to be converted into steam over and over again. Similarly, the cool water can be returned to the environment with no contamination.

For plants that convert natural gas into electricity, the gas must be burned just as the coal is burned in the previous example. Natural gas plants siphon in the natural gas and mix it with air before burning it. Aside from generating heat, this burning process also creates an expansion gas that builds up pressure and drives turbine blades (again quite similar to the process for coal burning plants). Before the combustion gas is released into the environment, it is cooled by using the heat to convert water into steam. Finally, the combustion gas is released through a tall construct known as a stack that is of sufficient height that the combustion gas will disperse before reaching ground level. In this way, natural gas plants are considered to be very environmentally friendly. The steam is also used to help spin the turbines, and then cooled in exactly the same manner as the steam from the coal burning plants.

Nuclear power plants work in a very similar manner. The source of heat that is used to convert water to steam is nuclear fission of uranium atoms. The core of the nuclear reactor contains control rods that are comprised of uranium oxide. These rods are struck by individual neutrons which sometimes cause a molecule of uranium oxide to release more neutrons. The energy that was initially used to bind the neutrons to the uranium oxide molecule can now be used to heat water exposed to pressure greater than 150 atmospheres to temperatures of 300 degrees centigrade. This high temperature water is cycled around much lower pressure water that is converted to steam and used to power turbines just as with the other two plants. The water from the core is cycled back to be reheated and the steam is collected and sent back to the steam generator where it is also reused. Most nuclear power plants use a sea or an ocean as the source for the water that is used to cool the steam.

In closing, it should be mentioned that each of these plants takes the generated electricity and run it through a system of transformers to convert it to a very high voltage. This high voltage electricity can now be easily transported wherever it needs to go. It is generally considered that nuclear power is an extremely clean form of electricity generation. Natural gas plants are also considered to be environmentally friendly, while the coal plants do not benefit from such a perception.

Sources:

http://www.duke-energy.com/about-energy/generating-electricity/coal-fired-how.asp

http://www.edfenergy.com/energyfuture/generation-gas

https://www.edfenergy.com/energyfuture/generation-nuclear