How is Ethanol Made?

Ethanol is most commonly found as a fuel additive.  Using ethanol is supposed to decrease dependence on oil, and it is debatable whether or not it achieves this goal.  I am not going to address this issue, as I will just state the facts.   Most gas stations use a mixture of about 10% ethanol with the rest normal gasoline.  The added ethanol has many advantages.  Compared to gasoline, ethanol burns much cleaner, as it contains more oxygen than gas, which has more carbon.  As a result, when burned ethanol releases oxygen instead of carbon dioxide to the environment.  Because of its high oxygen content, pure ethanol fuel has a very high octane rating.  This means that it will have a higher performance in your cars engine.  For this very reason, the Indy Racing League only uses 100% ethanol is all of their race cars.  Ethanol also has a very low freezing point, so it acts as a anti-freeze in the gas lines of your cars engine.  This also will allow your car to start easily at low temperatures.

Now that we know some reasons that ethanol is used, lets take a look at how it is made.  To make ethanol, a lot of corn is needed.  Corn is about 70% starch, 6% germ, 14% water, and 10% fiber.  To expose the starch for processing, the kernels are dumped into a grinder and ground into corn "flour".  Liquid is then added to the flour to create a mash.  This mash is heated in order to further break down the starch into sugar.  After cooling, the new mash is transported to a fermentation tank.  Yeast is added to begin the fermentation process where the sugar is made into alcohol.  After fermentation is complete, the alcohol has to be purified by removing the solid mash and water.  This process is called distillation, this process is repeated until the alcohol is 95% pure.  This almost pure alcohol goes through a molecular sleeve where the bigger alcohol molecules are separated from the water molecules.  When finished, the final product is 200 proof, or 100% alcohol.  This is shipped to a refinery for other processes to allow it to be added to gasoline.  The leftover syrup is added to the leftover mash and dehydrated to be sold to farms for use as cattle feed.  This mash, now called distiller grains has a nutritional value equal to or even better than whole corn.

Geothermal Energy

Geothermal energy is energy from heat inside the earth.  What does this mean?  How can we get energy from this?  Well, the Earth's core is extremely hot.  This heat is radiated through the magma and rock of the inner Earth.  The heat is used in many different ways.  One way is through a direct heating system.  In this system, hot water is pumped directly from within the Earth to buildings for use.  Electricity can also be produced using geothermal energy.  To produce electricity a geothermal plant is used.  There are three kinds of geothermal plants: dry steam plants, flash steam plants, and binary cycle power plants.  In a dry steam geothermal plant, steam is pumped straight from the Earth and used to turn the generators turbines.  This steam is produced from a geothermal reservoir in the Earth.  After it turns the turbines, the natural steam from this reservoir is condensed into cool water and pumped back underground into the reservoir so the process can continue.

The second type of geothermal electricity production is the flash steam method.  This is very similar to the dry steam method.  Instead of pumping steam directly from the Earth, hot water is pumped up.  This hot water is converted to steam to turn the turbines of a generator.  The cooled water is then pumped back into the reservoir just as in the dry steam plant.

The third type of geothermal power plant is the binary cycle power plant.  This method is a little different than the other two.  Instead of directly getting steam from a geothermal reservoir, hot water is pumped up and used to heat another liquid through a heat exchanger.  This liquid vaporizes and the vapor used to power the generator.  

Like any other renewable energy source, there are many benefits to using geothermal energy.  The use of  geothermal energy conserves fossil fuels, it is renewable, it produces green energy in a safe manner, and uses little land.  The United States is one of the biggest users of Geothermal energy and has even more potential for geothermal energy production. (see below graphic)

The Power of the Waves

After learning about solar and wind power, I thought hydropower would be a great next topic.  Hydropower is the most common source of renewable energy, as it accounts for about 67% of the United State's total renewable energy production.  First, let's talk about how hydropower works.  Hydropower uses the force of falling water to turn the turbine of a generator.  The water pressure is usually built up by damming a river, and then channeling the water down a large pipe called a penstock.  This increases the water pressure.  After the water turns the turbine, it flows back into the river on the other side of the dam.  This is a renewable source of energy because of the water cycle.  The water that flows out from the penstock will eventually evaporate and start back at the source of the river by rain, snow, or other precipitation.

Hydropower sounds simple enough, but there are several things that need to be considered.  Salmon are fish that swim upstream to spawn.  After spawning, the salmon and their offspring need to swim downstream to return to the ocean.  Damming a river makes it nearly impossible for these salmon to get upstream to their spawning grounds.  Even if they did get upstream, they could easily be killed by the dam on the way back down.  To prevent this problem, dams in rivers where salmon migrate have installed fish "ladders".  These fish ladders are simply a passage around the damn with a serious of steps.  The water flows fast enough over these steps to attract the fish but slow enough that they can leap over them without be washed back down.  

The Grand Coulee Dam in Grand Coulee, Washington produces more power than any other hydroelectric dam in the United States.  Although this dam produces billions of kilowatts of power annually and irrigates about 600,000 acres of farmland, it has no fish ladder.  This dam removed about a thousand miles of spawning grounds for several types of salmon.  This dam, like many others, has its pros and cons.  It is up to you to decide which outweighs the other.  A great video about hydropower can be found here : video. 

One of the Grand Coulee Dam's 33 turbines being assembled

                                                                                                                            

  

The Power of the Wind

After investigating solar power last week, I thought a good topic for this week would be wind power.  The reasons for using wind power are the same as solar, we are slowly but surely running out of fossil fuels.  Wind power is becoming more popular and a lot more high-tech.  First, lets look at how a wind turbine works.  As wind passes over the three blades, it causes them to turn.  This spins a shaft, in turn rotating the gears of a generator.  This may seem simple, but several variables can affect the amount of power generated.  The first one of these variables is wind speed.  The turbine can start generating electricity at about 8 mph.  Once wind speed reaches about 65 mph, the turbine will be stopped because these speeds could damage it.  The radius of the blades also affects the turbines total power output.  Doubling the radius quadruples the output!  Another factor is air density.  Heavier air (at a lower altitude) generates more power.  This is why offshore wind turbines are becoming more common.  With an average wind speed of just 15 mph over the course of a year, a single wind turbine with a blade radius of only 50 feet could power about 50 homes.

So exactly how much power can we get from wind?  Is it possible to rely entirely on wind for power?  To answer these questions, we will take a look at Denmark.  A large island off the coast of Denmark called Samso Island gets 100% of its power from wind.  This island is home to about 4,000 people, and all of there homes are supplied with electricity from wind turbines.  In the United States, wind power accounts for around 2-3% of our total power, and yet we are one of the leaders in wind power output.  The U.S Department of Energy's Energy Efficiency and Renewable Energy branch conducted a wind resource potential for the entire United States.  They concluded that the U.S has a capacity to produce 36,919,551 gigawatt hours of electricity.  The annual electricity consumption in the U.S in only about 4,119,000 gigawatt hours.  Keep in mind that is just the potential wind energy production, and it would cost a lot to meet that potential.  Wind power is becoming increasingly popular however, and combined with solar and other forms of energy production, the need for fossil fuels will decrease.

Wind Resource Potential Map

Here is a video that takes a look into a wind turbine...very cool, check it out!

VIDEO

All About Solar Energy

With the world's supply of fossil fuels such as coal, oil, and natural gas being depleted, alternate forms of energy production are in need.  One of these forms of energy production is solar energy.  The sun is arguably the biggest source of energy available to us.  It could easily provide us with all the energy we need, and it won't run out anytime soon.  There is only one problem...harnessing this energy.  Right now solar energy accounts for less than 1% of the world's total energy production.  About 85% of this energy production comes from fossil fuels.  Three of the major arguments against solar energy are that energy can only be produced in nice weather, there is no room for solar panels, and its cost.  Looking at the first issue, it is true that solar panels don't work effectively at night or during adverse weather.  However, there are very powerful batteries that can store the energy made during the day so that power can be used at night or during storms.  As for the issue of space, solar panels are bulky.  But think of the Sahara Desert.  It is estimated that an area of 640,000 square km could provide the world with nearly all the power it needs.  The Sahara Desert, one of the sunniest places in the world, spans 9,000,000 square km.  As for the cost of solar panels, they are pricey.  This is mainly because they require large amounts of silicon which is not readily available.  However, this price can be offset with time, as anyone who invested in solar would save money on energy in the long run.

 

After learning more about solar energy, you may ask, how does solar energy work?  Obviously I could go into great detail to answer this question, but I am going to keep it simple.  There are two different types, solar thermal and photovoltaic.  Solar thermal is used to generate heat from the Sun's energy.  I am going to focus on photovoltaic because this is how electricity is made from the Sun.  The solar panels in the photovoltaic method contain silicon (a semi-conductor) based solar cells that absorb the Sun's light.  Being a semi-condutor means the silicon readily donates its electrons.  The energy from the Sun's light "excites" the electrons in the silicon solar cells, creating electron flow or electricity.  This is in the form of a direct current or DC.  This DC power can be stored in a battery.  Since your house uses alternating current or AC power, the DC power has to flow through an inverter to change it to AC.  

  

Make Your Home Green!!

This weeks research topic is how to make your home green.  A green home can be defined as a home that uses less energy and creates less waste.  There are a great number of possibilities to make your home green, and I am going to explore just a few.  One step you could take would be to have an expert come and evaluate your home.  They would be able to recommend to you the most cost effective and efficient upgrades for your house.  A very simple, yet very overlooked energy saver is a compact fluorescent light bulb.  These light bulbs have a much longer life than incandescent light bulbs, and use a lot less electricity as well.  It is estimated that a compact fluorescent lamp can save around $50 over its life compared to an incandescent light bulb.  Another thing to think about is making sure your home is well insulated.  This can greatly reduce the costs of heating/cooling your home.  Buying energy star appliances can also save energy and money.  These appliances are deemed energy star efficient on the basis that they: contribute to significant energy savings nationwide, save money in the long run, and that their performance can be tested.  Green homes not only save the environment, they can save you a lot of money, so GO GREEN!!!

Transportation

To start things off, I would like to welcome you all to my new blog, GO GREEN!!!  This is a research blog that will investigate the many ways to help preserve our beautiful planet for future generations to enjoy.  My first topic will be transportation.  I will introduce to you the many ways that are available to get around in an environmental friendly manner.  I'll start out with the obvious; biking, walking, rollerblading, etc.  Not only are these methods healthy for the environment, they are healthy for your body as well.  One more obvious option is carpooling.  This will save you money, time (carpool lane), and wear on your vehicle.  On top of that, you'll cut down on harmful emissions.  One program, called NuRide, even rewards people for taking "greener" trips.  They estimate that there are an average 1.1 billion trips per day, and 78% of those are single drivers.  They also estimate that 50% of urban air pollution and 30% of greenhouse gas emission results from driving.  Since March 2004 NuRide users have prevented about 51,526 tons of emissions and saved 5,242,874 gallons of gas.  More information is available at www.nuride.com.  Public transit is another easy alternative to driving.  Metro Transit is the public transit organization in the Minneapolis/St. Paul area.  They offer public busses and light rail.  They use hybrid busses and new generation cleaner fuels.  If none of these methods are applicable or convenient for you, hybrids cars are extremely efficient.  Put very simply, a hybrid car has a gasoline engine and an electric motor.  The gasoline engine provides most of the power while the electric motor provides an extra kick for accelerating or when extra power is needed.  The battery is recharged by the gas engine so it never needs to be plugged in.  It is evident that there are many ways of traveling without polluting the environment, so GO GREEN!!!