Since it is so close to the AP exam and all of you have fulfilled your scribe post obligations, I won’t start the list over. So, here is a collection of links from past classes on major air pollution issues and global climate change for those that missed class. While written a year or two ago, all the info is still correct and relevant:
*Note: This is a guest post by MattP from the other class.
Before Mr. Thompson, the CEO of a Biodiesel fuel company, came to speak to us on Friday, what did our class know about Biodiesel fuel or even just diesel fuel? We knew that diesel fuel was more expensive at gas stations than gasoline, that trucks and other large vehicles often run on diesel fuel, and that diesel fuel would destroy a gasoline engine. But that was about it.
The first thing Mr. Thompson want to make clear to us was that BIODIESEL IS NOT ETHANOL. Ethanol is a corn-based fuel that is made by distilling the sugars and starches into alcohol. It is then mixed with gasoline. Ethanol is not only less efficient than gasoline but it also takes away from our food supply. Basic rule of economics: when the supply of a product decreases the price increases. On top of its lack of efficiency and the fact that it increases the price of food, because it is corn-based all the same fossil fuel inputs and environmental impacts associated with farming. When you add up all these costs ethanol is energy negative (it takes more energy to make it than it provides) and in the eyes of Mr. Thompson and many others to be a bad fuel.
Mr. Thompson went on to explain what biodiesel fuel actually is and does. Biodiesel is fuel made from natural oils (soy, canola, poultry, algae, or Mr. Thompson’s company made fuel from used cooking oil) that can be used in a diesel engine. It can be combined with petroleum-based diesel fuel in any percentage and still run a diesel engine. In fact, the main reason biodiesel even needs to be mixed with petrodiesel fuel is that it tends to congeal when it is cold and block up engines. Petrodiesel’s lower freezing point prevents this tendency when the two are mixed. Compared to regular diesel fuel biodiesel fuel can also reduce carbon emissions by as much as 75%.
Just a couple of videos to show you how biodiesel fits into our country today
Mr. Thompson finished his lesson by telling us what biodiesel is not. Again IT IS NOT ETHANOL. It is not simply waste vegetable oil taken from someones kitchen and dumped into a gas tank. It has to be processed first or else it would eventually ruin your engine. On the downside, in most places it is not cheaper than regular diesel fuel or gasoline or available in as great quantities… yet. But on the upside it is not flammable, hazardous, carcinogenic, and since it is just natural oils, it biodegrades very quickly.
Biodiesel fuel has many exiting possibilities and in a few decades it could be one of our major sources of fuel.
There are two different versions of this equation, the Metric version and the English (industry standard) version. They are the exact same equation, except for the units. We must also remember that the specific heat of water (the energy required to change the temperature of water by one degree celsius) is always 1. This is important because many home appliances and power plants heat water for various reasons.
The third equation is cost:
This is just a simple equation used to determine the total price paid for more than one product.
The fourth and final equation is efficiency:
This equation tells us how efficient a type of technology (light bulb, wind turbine, etc.) is. A higher level of efficiency is obviously the more desired amount.
Did you know that the sun is made up of about 70% hydrogen? Or that hydrogen is the most abundant element in the known universe? Hydrogen fuel cells will be the future of alternative energy. They are already being used to power vehicles made by large manufacturers such as Toyota and Hyundai. Check out this article for a bit more on the emerging use of fuel cells to replace gasoline and time consuming electric models Hydrogen fuel cell powered cars. Article source: http://money.cnn.com/2012/03/15/autos/hydrogen-fuel-cell-cars/index.htm
Even though hydrogen is the most abundant element in the universe, finding free hydrogen gas is extremely rare because it bonds with other molecules to form compounds like water and natural gas. So one way scientists obtain hydrogen gas is through a process called electrolysis in which electricity is applied to H2O molecules to split the compounds into hydrogen and oxygen gases. Here’s a simple video on the very basics of electrolysis how electrolysis works. And we will give a small demonstration in class using a model we built to separate the hydrogen and oxygen from water molecules.
There’s a reason wind power is the face of the alternative energy movement. It’s the energy of the future: renewable, releases no carbon emissions, and, most of all, it’s adaptable. If you don’t believe me, check out this recent article from New York’s The Real Deal about the installation of wind turbines at Staten Island’s Freshkills Landfill (you may remember this from a video earlier this year). Interested? Read on…
Typical Wind Farm
This video here from the US Department of Energy (some say it’s the authority on US energy use and management, but perhaps that’s just a rumor) is the best we found in explaining the mechanics and operation of a standard wind turbine. These turbines (the tall poles with the propeller looking thingies) are very simple in their operation. Essentially, wind blows the propellers which, with the help of various gears and devices, turn an internal turbine that activates a generator, ultimately creating electricity. We’ll go into more details tomorrow, but that should give you a good background.
Wind turbines may not produce as much energy as, let’s say, a nuclear power plant, but the fact that they’re safe and versatile increases their appeal. Wind farms (a collection of turbines) can be built on hills, plains, and even oceans. As long as there’s wind, electricity will be produced. However, I don’t want to give too much away, so stay tuned for tomorrow’s presentation, it’s guaranteed to be classy.
Most people probably associate the words “solar energy” with solar panels. That’s it. Just these shiny rectangular objects that you place on your home to cut down your power bill. But solar energy is so much more complex than that. Did you know that there are two main categories of solar energy? Those categories are passive and active solar energy. Passive solar heating doesn’t involve any form of technology–it’s natural.Meanwhile, active solar energy involves the use of technologies such as pipes. The video below will help you better understand this distinction.
To go into more depth, there are three types of active solar energy technologies: solar water heating systems, photovoltaic (PV) systems, and concentrating solar thermal (CST) systems.
Here is a video that goes into more detail on active solar water heating systems.
Below is a simplified picture of a photovoltaic (PV) system that displays the fact that light is converted into DC (direct current) and then AC (alternating current).
Below are pictures of concentrating solar thermal (CST) systems. As you can see, mirrors are used to collect heat to produce steam. The steam then powers turbines which generate electricity.
And, on another note, did you know that most governments subsidize solar energy projects in an effort to promote “clean” energy? One such example is Germany, and, after reading our short summary and the article, you will see why subsidies truly are an important part of solar energy.
While Germany contains a majority of the world’s photovoltaic(PV) cells (“capture energy from the Sun as light, not heat, and convert it directly into electricity”), the government underestimated the amount of subsidies it would have to give and has been forced to decrease government subsidies. Thus, Germany’s solar energy industry is suffering, and many employees are worried about the status of their employment.
*Note: Since we did not have enough folks to take this topic, here is a guest post by RayS and MattP from the other class.
Pikachu, quick use thunderbolt!
Critical Hit!
Foe’s Blastoise fainted.
For the millions of you that have played Pokemon, it seems obvious that electricity is water’s kryptonite; they don’t mix! But in the world of modern science, nearly twenty percent of all electricity comes from hydroelectric plants (imagine that Ash!). Source: Friedland and Relyea Environmental Science for AP
To illustrate the vast potential of Hydroelectricity as an alternative energy source, check out this brief video of China’s Three Gorges Damn (Danjiangkou Dam), the largest in the world.
Hydroelectric power uses dammed reservoirs to direct the flow of water through a penstock and then past a turbine that generates electricity. Watch this short video to see what I’m talking about, and if you don’t have time for the video, check out the diagram.
Diagram
Hydro electricity takes “hydro” and a substantial initial investment, and not all countries have the water and resources to make hydroelectric dams. The good new is that hydroelectricity emits no pollutants once constructed, and there are other ways to generate the hydroelectricity without a large river such as, run-o-the-river and tide. These use the same concepts, but don’t have reservoirs to direct the flow.
Get it? Got it? Good.
P.S.
Things to consider:
fish ladders: for migratory fish during their mating season.
Siltation: the plague o’ hydroelectric dams! Silt from the water builds up behind the dam and has the potential to clog the penstock.
So, what’s the latest trend in energy sources these days? The use of geothermal energy is heating up all over the United States. In just 2011 the industry was heating areas in 9 states and had projects in 15 states. Geothermal energy uses the heat from the Earth’s crust to provide energy with low CO2 emissions (clean energy). Other than having low CO2 emissions, it is also a renewable resource and except for the expenses of building the pumps to access the heat, it’s fairly inexpensive. So why not hop on the steam engine to success? California seems to be “full steam ahead” but is it really? This NPR article talks about California being on board to converting their energy sources by 2020 to all renewable sources but it seems that the geysers they’ve been tapping for steam are running out.
Photo: California Geysers located in Mayacamas Mountains, San Fransisco, CA are part of the first geothermal energy plant. Here, workers are trying to repair the 50 year old site. Click here to learn more about The Geysers.
Their solution is to drill down into the Earth’s crust where the temperature is around 500 degrees and use that heat, but of course it can’t be that easy. Building geothermal energy facilities can not only be expensive, but can cause minor earthquakes too. Eventually the AltaRockgroup, a company that leads in energy production and technology for geothermal energy, gave up at sites in California and moved on to try Oregon.
In Oregon, geothermal energy developers plan to pump water into a dormant volcano for energy. Read about this plan here!
This short clip can give you an idea of what the scientists had in mind regarding the volcano in Oregon (on a much greater level of course)At the Timanfaya National Park, water was poured into a bore hole that heated the water and shot it back out.
The United States aren’t the only ones trying to lower their carbon footprint and use geothermal energy. Here’s a 2minute video talking about Canada’s plans regarding geothermal energy.
As you can see, geothermal energy has become quite a hot topic recently and it is predicted to become an even bigger project in the future.
This type of biofuel is known as biodiesel. As the article mentions, the use of cooking oil as fuel for the plane does reduce the dependence on petroleum, thus acting as a substitute. However, this doesn’t mean that the process is any less expensive. In fact, using the biodiesel turned out to be much more expensive than using all petroleum as jet fuel. So, there are obviously advantages and disadvantages to this alternative energy source.
So, what are some other alternative sources of energy? Another common biofuel that we use is ethanol, an alcohol that is mixed with gasoline to produce a mixture called gasohol (the most common mixture in the United States is 10% ethanol, 90% gasoline). How is it produced? Take a look at this short video clip from the Ethanol Promotion and Information Council (the last 30 seconds of the video promote the use and production of ethanol in the United States–presenting a clear bias–however, the first 3 min and 20 secs describe the process with easy-to-follow animations):
So basically, there are two ways to produce ethanol: from corn and other starchy crops, and also from cellulosic materials. The issue that many bring up with ethanol production from corn is that it will drive food prices up. Take a look at this article from February 2011 in USA Today about the threat that ethanol production brings to the world’s poor as food prices rise due to less corn in production for food: http://www.usatoday.com/money/industries/food/2011-02-09-corn-low_N.htm
Finally, not all countries in the world (especially developing) have the capital or the infrastructure to produce and use biofuels, like ethanol and biodiesel. As a result, more of the developing world uses solid biomass as their source of biomass energy. One such source is charcoal. But how is it made? Take a look at this video taken from an episode on Discovery Channel’s “How it’s Made” series which describes the industrial charcoal production process (stop at 3 min–the rest of the video describes what happens to the charcoal pieces that are used for grilling purposes):
Since it is produced from heating wood, charcoal is a renewable energy source. Using these forms of biomass energy is an important piece of renewable energy. In fact, biomass energy accounts for more than half of renewable energy in the US (textbook).
