Month: October 2015

The first thing that caught my attention in the powerpoint was that nuclear energy didn’t receive a lot of attention until 1939– the same year Hitler invaded Poland. Most of the heavy research about atomic radiation took place from 1939-1945, which were the years that WWII occurred. It’s troubling that it really took the war for people to focus on this research, and even then it was mostly motivated by the idea that it could be weaponized. After the war, the focus was on using radiation to create energy, both to propel submarines and then for safe and reliable power output in the form of plants. A serious advantage of nuclear energy is that Uranium is much more potent than gasoline or coal. A smaller amount goes a much farther way than its alternatives. And because it releases fewer pollutants, using nuclear energy helps to prevent further harm to the atmosphere.

 

Nuclear power plants use both fission and fusion to create energy. Fusion is of course the fusing of two different atoms, for example when two Hydrogen molecules with extra neutrons bond with two spare neutrons to create a Helium molecule as well as a neutron. This process also releases extra energy, which is what is used to heat tanks of water, creating the steam that powers turbines, generating electricity. Fission works in a similar way, although instead of two molecules coming together, it’s one molecule that splits. Uranium-235 is the most common material for fission, although U-236 is also used. When one of these atoms is split, it starts a chain reaction which causes other atoms to split. With every split, some energy is released, so eventually the whole supply has split and enough energy has been released in the form of heat to turn the water into a nearby tank into steam, powering turbines which in turn generate electricity.



I found the chart on radiation doses to be really fascinating. I vaguely remembered from a past class that almost everything releases some radiation, but it was cool to see a list of some of the sources we might encounter. It’s cool to remember that human bodies produce radiation as well! Although it was less cool when I got to the next slide and remembered all of the damages that can occur from radiation… and it’s especially scary that genetic defects can appear the generation after somebody has been exposed.

 

I’m intrigued by the short slide on Yucca Mountain– why did that plan get cancelled? I hope we discuss that in class!

On March 11, 2011, a 45-foot tsunami hit Japan as a result of a 9.0 earthquake on the Richter scale. The tsunami hit three cooling towers and disabled their power, causing them to melt within three days. Another cooler was written off as damage in addition to those three melted coolers. The earthquake caused over 19,000 lives, but the power plants survived the earthquake with minimal damage. The tsunami, however, caused considerable damage. When the plants were built, it was believed that tsunamis this large were highly unlikely to come to that area, but with more research we know now that those early estimations were incorrect. Because of this tsunami and the consequent nuclear disaster, more than 30,000 people had to be evacuated out of the most dangerous areas. Although the earthquake and consequent tsunami occurred on March 11th, it took until the 12th for workers to discover radioactive material leaking out of the front entrance. The internal pressure was too much for the plant, especially with the coolers having melted, so it expelled toxic materials to lessen the pressure. It has been estimated that the amount of toxic materials is about 20% of the toxic materials that were emitted at the Chernobyl disaster.

(Fukushima Daiichi disaster. Source: FukushimaPic.jpg)

 

Since the nuclear plants were shut down after this disaster, Japan has gotten about 90% of its energy from fossil fuels, the majority of which were imported from the Middle East. A recent plan was announced by the Japanese government explaining they will reopen their shut down nuclear plants with tightened safety regulations. The government also intends to continue to research renewable energy, like solar and wind. The citizens are still uneasy; it is difficult for anyone to support nuclear energy after what their country has already endured. And, on top of that, the continued use of coal and oil is not exactly stellar for the planet. But, with these prices rising, the government has become aware that they need to slow down their fossil fuel consumption, and to the great discomfort of many of their citizens, have decided that nuclear energy is again the answer.

Sources:

http://www.world-nuclear.org/info/safety-and-security/safety-of-plants/fukushima-accident/

http://fukushimaontheglobe.com/the-earthquake-and-the-nuclear-accident/whats-happened

http://www.wsj.com/articles/japan-struggles-to-find-balanced-energy-strategy-1431545581

(President Obama announcing his new Climate Action Plan. Source: obama_energy.jpg)

 

In June of 2013, President Obama released his Climate Action Plan outlining his intentions for slowing down the current trends of climate change. Although this plan had more than thirty ideas, three stuck out to me in particular: Cutting carbon emissions from power plants, increasing fuel economy standards, and preserving the role of forests in mitigating climate change.

 

According to the Climate Action Plan, “Power plants are the largest concentrated source of emissions in the United States, together accounting for roughly one-third of all domestic greenhouse gas emissions.” Because these plants are such a major contributor to our country’s emissions, it is important for our government to determine which emitted chemicals are most dangerous for our climate, and then act to restrict those. In 2013, mercury, arsenic, and lead emissions were all limited, but carbon pollution from power plants was completely unrestricted. At the state level, more than half the country had renewable energy targets in place, and exactly half of the country had set energy efficiency targets. These kinds of numbers prove that people care about pollutants and energy sources. In this Climate Action Plan, the White House promises to modernize the power plants so that their emissions are cleaner as well as continue to expand into clean energy sources like efficient natural gas and renewables. Specifically, the White House promises to assign the EPA to the task of creating carbon pollution standards for all power plants, something that had worked in the past with fuel emissions and the standards the EPA had created there.

 

In 2013, heavy-duty vehicles were the second largest emitter of greenhouse gases in the transportation sector. The Obama administration had already shown that auto-emissions was an issue they considered a priority; in 2011 they set the first ever fuel economy standards for the larger vehicles that emit more pollutants. Because of these standards, it was projected that greenhouse gas emissions would be reduced by approximately 270 million metric tons and 530 million barrels of oil would be saved. And with passenger cars, this administration has already set the strictest standards in the U.S. to date. From the Climate Action Plan: “These standards require an average performance equivalent of 54.5 miles per gallon by 2025, which will save the average driver more than $8,000 in fuel costs over the lifetime of the vehicle and eliminate six billion metric tons of carbon pollution – more than the United States emits in an entire year.”

 

In terms of steps to help remove some of the pollutants already in the air, there is a major source of help the government is looking to preserve: trees. According to the Climate Action plan, American forests remover 12% of the greenhouse gases released every year. This capacity to remove these gases is fragile, however, because of wildfires and deforestation, to name a few causes. The Obama Administration explains that they will continue to look into new ways to protect and restore forests as well as grasslands and marshes and other fragile ecosystems.

According to the national energy authority of Iceland, 25% of the country’s total energy production is from geothermal energy. In the start of the 20th century, the country was poor and not very green, as most of the energy used was from imported coal and peat. However, by 2014, “85% of primary energy use in Iceland came from indigenous renewable resources. Thereof 66% was from geothermal.” (Source: http://www.nea.is/geothermal/) The country’s residents have been using geothermal energy for small projects for generations, like heating small pools or drying fish, or for making Iceland’s famous hverabrauth, or “hot spring bread”. In 1930 the country harnessed some of the heat by drilling holes and running pipes from the holes three kilometers away into a primary school, keeping it warm all year round. In the 1970s the country really started using this energy, because up until this point private homes almost entirely ran on oil. Now Iceland has become the leading expert on geothermal energy and works to inspire other countries who are looking into it, such as Germany, China, and the Philippines. A short video from Scientific American shows exactly what these hot springs are like and how their energy is used: http://video.scientificamerican.com/services/player/bcpid1753162298?bctid=1873043478

 

Another source (Scientific American) quotes Iceland’s renewable energy usage at 99%, leaving only 1% of their usage from a nonrenewable source. It’s no wonder that Iceland is leading the revolution on geothermal energy. In the Philippines, there is an easily accessible bank of underground heat which is not currently being used to its full potential, and in Germany a tariff has recently been introduced with 20 cents per kWH of geothermal energy. Other forms of geothermal energy have been looked at, such as supercritical steam, which the European Union, the Icelandic government, and the US National Science Foundation have worked together to explore through the IDDP, the Iceland Deep Drilling Project. The country expects to continue to grow its output of geothermal energy and hopes to share this energy with the rest of the world as they have done with a province in China which is currently being heated by Iceland’s third largest bank of geothermal energy. We can only hope that we can continue to grow our worldwide usage of geothermal energy and cut down on some of our more harmful energy sources in our attempt to preserve the world we have the way it is.

 

Sources:

http://www.nea.is/geothermal

http://www.scientificamerican.com/article/iceland-geothermal-power/

The Stirling Heat engine was invented in 1816 by Robert Stirling. He was trying to create a better, more effective steam engine, which often exploded because of high steam pressure. In essence, the Stirling engine functions like other heat engines in that it converts heat energy into mechanical energy, but unlike other engines, the Stirling is closed cycle, meaning that it uses a fixed amount of air or whatever fluid it is using which never leaves the chamber, and it is heated from the outside. Because of this, the Stirling engine can run on any heat source: solar, wind, fossil fuel, chemical, etc. It can run on a very small difference in temperature, as low as 7 degrees Celsius, so it can even be powered by steam from a cup of coffee or body heat.

(How a Stirling Engine runs. Source: http://www.mpoweruk.com/images/sterling_engine.gif)

 

Peltier Devices run based on the Peltier Effect, discovered by Jean Peltier in 1834. The Peltier Effect is also sometimes called thermoelectric cooling, which occurs when an electric current goes through a thermocouple, a “junction of two dissimilar conductors” (Source B.). It was known that when this occurred, there was a heat current, Joule heating, but Peltier discovered in his experiments that his current was too hot to be just Joule heating. This process occurs when two conductors are in electric contact, causing electrons to flow from the more electron-bound conductor to the less electron-bound conductor. Then, the change in electrostatic potential caused by the moving of electrons causes a temperature gradient. The right materials have to be chosen, but a perfect Peltier device looks like the one pictured below:

(How a Peltier Device runs. Source: http://www.activecool.com/technotes/images/TEC_JC.jpg)

 

Both devices have serious modern benefits. Both are much quieter than their common alternatives, making them ideal for situations when silence is of the upmost importance. Peltier Devices are used in submarines, for example, when stealth is required for operations. Both devices are also more energy efficient and greener than others. The Peltier Device, unlike similar products, uses no CFCs, which are harmful to our atmosphere. The Stirling engine can run on solar power, the benefits of which have already been discussed in other posts on this blog. Both devices work to enhance naturally occurring scientific phenomena and create cleaner, safer, and more efficient energy and temperature changes.

 

Sources:

A. http://www.mpoweruk.com/stirling_engine.htm

B. http://www.activecool.com/technotes/thermoelectric.html

C. http://www.physics.rutgers.edu/ugrad/351/oldslides/Lecture11.pdf

The Tesla car is a potentially revolutionary vehicle in terms of environmental impact as well as cost of use. The Tesla company released their first car in 2008, and continues to release new models periodically while perfecting their mechanisms. Unlike most other cars, Tesla cars are mostly battery operated, and need to be charged in order to work. Unlike Priuses or other hybrids, the Tesla has no gasoline powered motors. Instead they have a large lithium-ion battery, the same kinds of batteries that are in MacBooks. Like a laptop, the Tesla batteries hold a charge for a certain amount of time until they need to be plugged in again, but unlike a laptop, these batteries are large enough to operate cars for hours. According to Tesla, their most powerful battery can run a car going 55 mph for 300 miles before it needs to recharge. The weight of a single Tesla battery is as much as 1000 lbs. These heavy, powerful batteries power motors that are more advanced than combustion motors; they get significantly more miles per charge than the other motors get per gallon.

 

Environmentally these cars are a dream, but they are still unaffordable for the majority of the masses. The starting price for the basic model is $101,500, and although gas costs less than electricity in most places and the cost of use is less than a combustion motor, the original purchase is much more than most can pay. The other hassle about the Tesla car is where to charge the car. The company suggests getting an electrician to install a high power charging port in one’s garage so that it can charge more quickly with more voltage than other outlets. Even with charging stations in garages, there are few charging stations in other areas, although there are more opening in different gas stations across California. Theoretically if these cars continue to grow in popularity then more charging ports will be installed publicly, solving the problem of sparse opportunities to repower. However the cost will still be out of reach for many. The positives of the Tesla car still seem to heavily outweigh the negative, especially considering the Tesla car releases just 15 tons of CO2 for every 160 tons that combustion engines release.

 

Sources:

http://www.teslamotors.com/about

http://mashable.com/2013/01/17/tesla-electric-car/#B1FPHQy5D5qT

http://visual.ly/how-electric-cars-and-tesla-model-s-work

There are three major sources of energy in the U.S. right now: nuclear energy, coal-based energy, and natural gas. All three operate in the same basic way, by converting water into steam which powers turbines that are connected to generators. However, the process of heating up water is very different in each case.

 

Nuclear Energy:

Nuclear power plants are to thank for about 20% of the U.S.’s energy today. In these plants, atoms of uranium are split through nuclear fission. Two different isotopes of uranium can be used in these plants: U-238, which is most common, and U-235. These isotopes are unstable, and when these atoms are split, the nuclei release neutrons, as well as heat energy. The neutrons that are released bump into other atoms, causing them to also release neutrons and heat energy, making a self-sustaining system. These uranium isotopes are contained in tubes that, when inserted into the system, are surrounded by water. When the heat energy is released, the heat goes into the water and converts it into steam.

 

(An image of a nuclear power plant as made famous on The Simpsons. Source: http://www.risefeed.com/wp-content/uploads/2015/08/Springfield_Nuclear_Power_Plant2.png)

Nuclear energy is not renewable, but it is sustainable, meaning that while there is not a limitless supply of uranium like there is sun or wind, there is enough to continue to power nuclear plants for roughly one hundred years. A very small amount of uranium can produce the same amount of energy as large amounts of coal and natural gas. There are no greenhouse gases that are emitted through nuclear fission since nothing is burned the way it is with other energy sources. What radioactive waste there is is kept contained until the radioactivity decreases enough that it can be released without harming the environment or people. Unfortunately, as nice as the pros here are, the con is that its safety is not foolproof. Chernobyl was once thought to be safe, and we all know now that that land is still unsafe to live on. More recently, the Fukushima disaster in 2011 encouraged some countries to phase out their nuclear power plants in case some similar emergency could occur there, but the U.S. continues to heavily rely on nuclear power with no intention to stop.

 

Coal:

Coal is burned, creating the heat that allows water to change into the steam that powers the generators. The coal is first ground into a fine powder, allowing it to burn more quickly and at a hotter temperature. The diagram below shows exactly how coal becomes electricity in the ways I have already described:

(How coal is burned to power generators. Source: http://www.worldcoal.org/media/jpg/585/174139cgart.jpg)

 

Coal has been the basis of the energy in this country for generations and is still used heavily, although recently companies have been working to make their systems more efficient so that the same amount of coal can produce more energy and fewer byproducts such as CO2 and other greenhouse gases. Newer systems are also planning on being fitted with CO2 capture systems which can help filter carbon dioxide and prevent it from entering the atmosphere. Although this energy system has been around for ages, today there is much work being put into modernizing it to help cut costs and pollution, two of the biggest concerns about relying on coal-powered energy.

 

Natural Gas:

Natural gas occurs from plants and animals that have died and decomposed thousands of years ago. The energy that they had gained from the sun is contained in the form of carbon in natural gas. This natural gas is a fossil fuel that is harvested through the process of fracking, something I have already explained in an earlier blog post. Once the natural gas is available for use, it is treated for impurities so it can be made more efficient, and then it can be converted into usable energy in two different ways. As in the case of coal, natural gas can be burned to produce steam from water and the steam powers turbines which in turn power generators. Another system in use is bypassing the water entirely and just burning natural gases in a combustion turbine which directly produce electricity. Recently it was discovered that it is possible to use these two systems at the same time, so that steam and gas vapors are both used to power turbines, resulting in the same amount of gas being used twice and producing twice the amount of energy.

(The path of natural gas form its source to the consumer of its produced energy. Source: https://www2.dteenergy.com/wps/wcm/connect/08d8250d-ff32-4b69-aee3-d3552d45f240/naturalGasIndustry.gif?MOD=AJPERES&CACHEID=08d8250d-ff32-4b69-aee3-d3552d45f240)

 

Burning natural gas does produce fossil fuels like NO and CO2, but it produces these in smaller quantities than the burning of coal does, for example. Methane can leak out in a few places during the process of harvesting, transporting, or burning as well. Minimal solid waste is produced from burning natural gas, but that should not suggest that this is a harmless energy source. Fracking can destroy agriculture, natural habitats, and communities, even when done correctly and carefully. Harvesting coal is much safer, as is mining uranium when done properly.

 

All sources have positive elements but troublingly they also all have seriously negative elements. It is important to remember that these three sources, while the biggest sources for energy in the U.S., are not the only available options. Solar energy and wind energy are just two of the increasingly popular renewable and clean energy sources we have available today, and neither of those are nearly as harmful as fracking has been in Appalachia or nuclear energy has been in Japan.

 

Sources:

http://www.nei.org/Knowledge-Center/How-Nuclear-Reactors-Work

http://www.worldcoal.org/coal/uses-of-coal/coal-electricity/

http://www.epa.gov/cleanenergy/energy-and-you/affect/natural-gas.html

Fracking is a method used to extract natural gas from deep into the earth. First, a well is drilled, and then a high-pressure mixture of water, sand, and various chemicals is expelled from a hose, causing gas and oil underneath shale to be released into the well where it can be gathered for consumption. Fracking, or hydraulic fracturing, allows us to access fossil fuels underneath our own soil, making the U.S. less dependent on other countries for energy sources. In fact, because of fracking, it has been estimated that the U.S. has enough oil and natural gas to be secure for just under one hundred years, something President Obama announced in his 2012 State of the Union.

 

Despite the optimism in the U.S. government and among big oil companies, fracking is not necessarily as bountiful and harmless as once believed. Recent data shows there may not be as much shale as once thought, meaning there are fewer places where fracking will successfully lead to harvesting natural gas and oil. Accurate data is difficult to gather, even in the U.S., where we have more shale gas wells providing data than any other country. Other countries are considering following the U.S.’s lead on natural gas, but data will be even more difficult for countries such as the U.K. and Poland where there is much less shale.

 

There are more problems than just inaccurate data about the amount of shale. The environmental concerns about fracking are vast and varied. Fracking causes small tremors in the earth, too small to be felt, usually, but they could potentially add up over time and contribute to unsafe land. Environmentalists also suggest that dependence on natural gas and oils found through fracking is distracting us from more environmentally friendly energy sources (solar, wind, etc). Lots of water is used in fracking; water that, for example, might have been used to help the citizens of California in the bad drought they’ve been experiencing recently. My biggest concern about fracking was brought to light when a high school teacher showed the film Gasland during class: fracking frequently pollutes the water supply in the surrounding area. One part of the film was devoted to people who lived near fracking sites, and in one scene, residents showed the camera crew that when they turned on the faucet and held a lighter near it, they were able to set the stream of water on fire. That cannot possible be safe drinking water. Animals in the area were having health problems as well as humans, forcing many people to move from the houses they had once been comfortable and safe living in. I cannot forget that film and the impact that fracking had on those lives. It is clear to me that the cons heavily outweigh the pros, but oil executives are much more concerned with the cheap cost of this gas than the health of the citizens of the country whose land they are ruining.

 

Sources:

http://www.bbc.com/news/uk-14432401

http://www.foodandwaterwatch.org/water/fracking/

http://www.nature.com/news/natural-gas-the-fracking-fallacy-1.16430