The French physicist, Jean Peltier, who lived from the years of 1785- 1845, created the Peltier device. He mastered the innovative technique of the calorific effect of electric current through friction between two different metals. This is now deemed the Peltier Effect. There needs to be two different junctions available for the heating or cooling process to occur. For the times, Jean Peltier was very successful. Although the device was more expensive than alternative energy production it was much better for the environment. Jean Peltier: An Environmental Man!
“The Peltier technology works in a particularly economical and energy-saving manner at temperatures close to ambient temperature, since energy is only required if heating or cooling is needed, in contrast to compressor technology. Very fine adjustments can be made here to the heating or cooling functions.”
“In heating operation, in the same way as in a heat pump, thermal energy is removed from the ambient air and introduced into the inner chamber. Because of the closed Peltier cooling system, no outside air is exchanged. The advantages: No de-humidification of the inner chamber and a notably reduced risk of contamination.”
In today’s world the Peltier device and thermoelectrical technology is used in many components. This technology can be found in camping equipment, portable coolers, and small instruments. Surprisingly, electronic equipment intended for military use on the field or in battle is thermoelectrically cooled. The cooling effect of the Peltier heat pumps can also extract water from the air in dehumidifiers. Photon detectors within some astronomical telescopes or expensive digital cameras are usually cooled down with Peltier devices. Generally the Peltier device is used in the chilling of beverages. Excitingly, some products can also reverse the current to heat the beverage as well. There are many A/C car adapter coolers and even USB beverage coolers which use the Peltier device.
Here is an outline of our lab, what we hope to achieve, and how we hope to do it.
Purpose:
Can we generate electricity by exploiting temperature differentials in water?
Introduction:
By using a basic Peltier Device, we should be able to generate an electrical current using only water and a minimal amount of other materials. We expect to find that by creating a larger temperature differential we will be able to produce more energy. As the temperatures differential naturally closes, we expect the voltage to decrease. We also expect to generate enough energy to turn on a light or a small string of lights.
Materials:
Two plastic cups. Water. Wires. Lego Mindstorm Software. Lego Mindstorm voltage recorder. Lights. Metal panels.
Procedure:
First we will gather and set up the materials. The two cups will sit next to each other. One cup will be filled with hot water, one with cold. We will place the adjoining metal plates over the two cups so that one panel is sitting in each of the cups. The heat and cold from the water will cause the entire panel to get hot or cold. The Voltage Recorder will then sit in between the two panels. The heat differential will create a current in the voltage recorder. This is then connected to the MindStorm software via a USB cord. The wires will then continue form the recorder to the light(s). We will measure the temperature of the water and the voltage simultaneously. Then we will wait for a yet-to-be-decided increment of time and record again. We will be graphing electricity generated versus temperature differential, temperature of hot water cup, and temperature of cold water cup.
Tom Vales, who works in electricl and computer engineering, came to visit us in our classroom. He brought with him several different machines that generate electricity to run motors. The first machine he brought is called a Peltier motor. The Peltier device, named after the French physicist of the same name, uses heat differential to generate electricity. This works by placing one wire in a cup of hot water and another in a cup of cold water adjacent to it. Charge carriers diffuse from the hot side to the cold side of the wire creating a current. The electricity then causes the a fan at the top to turn. The next machine we saw was a hot water engine. This engine converts heat energy directly to mechanical energy. The Mendocino Motor works using solar energy. He fixed a light so that it would shine on a solar cell. The cell converts light into usable electricity. There is a wooden shaft with a four magnets around the middle of it. He places the wood above another magnet (and between two hoops at each end, for guidance). The magnet at the bottom repels the magnet attached to the wood and causes it to turn 90 degrees. The repetitive, continual 90 degree turns makes the wood essentially spin and hover in the air.
The final machine he showed us was the Tesla Coil. This was much larger than the others, standing perhaps 5 or 6 feet tall. MR. Vales’ coil is made of a plastic bucket with wire wrapped around it, sitting on a wooden cart, with an antenna on top. The machine creates a high voltage of electricity but at a low frequency. The low frequency is important because that makes the light visibly purple to us. As Mr. Vales turns on the machine, it appears that lightening in shooting out of the top of the machine. He raises a photoluminescent light, which then ‘turns on’ due to the electricity in the air. The machine is used hypothetically for the wireless transferral of electricity, but in reality is mostly for entertainment and educational purposes.
Nuclear Fusion will hopefully one day be a means of producing energy for the world to use. Basically, hydrogen nuclei are fused together. The mass of the newly formed nuclei is less than the sum of the total hydrogen nuclei. This excess mass is released as energy. The process is infinitely more complicated than that, but for the purposes of this blog, it will do. Hydrogen atoms have a positive charge, so forcing them to fuse is incredibly hard since they repel each other. In order to fuse them you need to create the right conditions. One of those conditions is very high temperatures. It is hard to describe or explain how hot the hydrogen needs to be. It is about 6 times hotter than the core of the sun. Hydrogen is no longer a gas at these high temperatures. It becomes a plasma. A plasma is a state of matter when the electrons no longer orbit/affect the atoms. They will have more energy to fuse than the electrical repulsion of their charge.
This is where the research at MIT comes into play. We visited the Plasma Science and Fusion Center at MIT. They study the science used to create those extreme conditions – microwaves, lasers, and ion particles. The team at MIT uses microwaves to heat the plasma. To contain it, they use a toroidal nuclear fusion reactor that suspends the plasma in a magnetic field. The experimental nuclear fusion reactor used at MIT is the Alcator C-Mod.
There is much more science involved than simply building bigger or more powerful microwaves. They design ways to measure the temperature of the plasma by analyzing the change in infrared lights, for example. They also developed bolts strong enough to prevent a spaceship from taking off. That takes two bolts, the reactor takes 86. So how is this specific research relevant in the greater quest for Nuclear Fusion (And therefore worth investment)? The technology that they test and develop is shared with the scientific community through different outlets (publications, seminars) and therefore directly contributes to the effort. The ITER Nuclear Fusion Reactor, the culmination of the international effort, is a project being funded by 33 countries. ITER is currently in the production stage in France. The ITER Reactor will hopefully be the first project to achieve this revolutionary milestone. The Research done at places like MIT, which directly contribute to that global goal, is therefore incredibly relevant and significant. In my opinion, this research is well worth investment.
Indian Point Nuclear Center is located 38 miles north of New York City in Buchanan, New York. It is home to a nuclear power plant that supplies around 30% of the power in Westchester County and New York City. The Entergy Corporation, which owns Indian Point, wants to renew its operating permits for 20 more years. Local governments and environmentalists, however, would rather see the center closed. Here is a breakdown of some of the pros and cons regarding the issue.
Pros: Indian Point is a safety risk. On September 11, 2001, it is said that the two airplanes that struck the World Trade Center flew over Indian Point. The thought of a terrorist attack occurring at Indian Point has caused many locals to abdicate for its closing. If one or both of the planes had hit Indian Point, there could have been a nuclear crisis affecting one of the most densely populated parts of the country for years. Around 20 million people live within 50 miles of Indian Point.
Pros: Other safety risks: The reactor was built in the mid 1970‘s. This causes some to fear the increased risk of malfunction. In January, 2012, Indian Point shut down one of its reactors due to a problem in a cooling pump. This scares a lot of people because as we have seen in the past (Fukushima), many problems can arise from malfunctioning or defunct cooling operations.
Pros: Environmental impact. There are also fears that radioactive material can be leaking into the Hudson River. In 2005, workers found a leak in a building containing radioactive water. tritium and strontium 90 were leaked into the river. The New York Times also reported finding nickel-63 and strontium in groundwater in 2006.
Cons: Loss of Energy. It is unclear whether or not the energy produced at Indian Point could be replaced by other sources. The idea is that the energy would be provided by a multitude of sources, divvying up the responsibility. Some energy would come from renewable sources like wind and solar. Some would come from increased productivity and efficiency at other plants.
Cons: Safety a non-factor. Entergy has explained that the problem with the cooling pump has nothing to do with an aging plant. The part that needed to be replaced is not original. It was simply unsafe to do the repair while operational.
Cons: Economic impact. Indian Point employs and supports the employment of approximately 2,500 jobs. It also generates somewhere around 3 billion dollars for the nearby counties, New York State, and the country.
Personally, I would prefer Indian Point shut down. My family lives within the 50 mile radius so the consequences of an attack or meltdown would affect me. I do not live close enough, however, for my community to benefit from the economic power of Indian Point. I also think that New York needs to be more of a leader with renewable energy sources.
http://www.thedailycortlandt.com/news/greenburgh-reiterates-call-close-indian-point
http://www.safesecurevital.com/
http://www.nydailynews.com/topics/Indian%20Point%20Nuclear%20Power%20Plant
