Cook 1 Cody Cook Physics Nelson Kilmer 29 September 2011 Storable Wind As we all know fossil fuels are coming to an end. Simply put we need a new, clean and renewable source of energy for the future. There are numerous different ideas for the future and many have the ability to become part of the energy system of the future. One energy source in particular that has the possibility to make up a large percentage of this system is wind energy. Wind energy is nearly endless and is environmentally friendly as well. Wind Energy So what does “Wind Energy” refer to? Wind is created by differing levels of heat applied to the surface of earth by the sun. This inconsistent heating causes the air to expand unevenly creating different air pressures. Pressure differentials cause the air to flow from areas of higher to lower pressure. This movement of the air from high to low pressure creates motion or kinetic energy. We call this kinetic energy of the wind “Wind Energy”. This “Wind Energy” can then be harnessed by generators. Said generators convert the kinetic energy of the wind into the more useful form of energy, electrical energy. These generators are the most noticeable portion of wind energy production. The most common type of wind generator is the tall mono tower wind turbines, which consist of a tall tower with a generator at the top with vertical spinning blades. A less common type is the vertical sail wind turbines, which has three large “sails” that rotate Cook 2 horizontally above a generator. Mono tower wind turbines are commonly used in commercial applications because they have a higher efficiency with straight winds. The wind, as shown below turns the blades which then, turn the generator that converts the kinetic energy into electrical energy. This energy is put into the electrical grid that supplies the electricity to your house and everywhere else in this country. Wind generators work wonderfully when the wind is blowing and there is demand for electricity. However there are times when the availability of wind and the demand for its power do not match. If the wind is blowing but there is not a demand for electricity, turbines are not turning and therefor they are wasting energy. The opposite situation is almost as problematic when the power companies cannot count on turbines to help meet the demands on the grid. This leads one to the question, can we store this free and clean energy source for later use? Hydrogen Production One option for storing wind energy would be to store the energy as pure hydrogen, the most abundant element in the universe. This is not a new idea; in fact there are plans to run vehicles on hydrogen via the hydrogen fuel cell going back as early as the 1950 s. At the moment these vehicles can drive up to 300 miles on a single tank of hydrogen (Bontrager). The problem with hydrogen is trying to procure it in a pure form that is then able to release energy when put into a fuel cell. The most common form of creating large amounts of hydrogen is Cook 3 electrolysis of water. The way electrolysis works is that an electric current is passed through water, this current breaks the bonds between the hydrogen and oxygen. The atoms then collect along there charges, hydrogen on the negative electrode and the oxygen on the positive electrode. The gasses are then gathered and stored for later use. Using Hydrogen Energy Storage to Utilize Wind Energy as a Constant Energy Source “Hydrogen, in combination with electricity, is widely recognized as one of the futures most outstanding energy carriers, while it will also be a contributing factor to the further integration of wind energy within the electricity distribution grid,” (Koroneos 649). This one statement and the research behind it is changing the world of energy production. The issue that is keeping wind power at less than ten percent is the inconsistency of wind (Koroneos 649). If this one obstacle could be overcome wind energy could account for most, if not all our energy needs. I believe that the production and storage of hydrogen is the way to make wind a consistent and viable option for energy production. When connecting wind generators to the electricity grid and having an electrolysis plant near these large wind farm creates the most feasible option. Currently large amounts of wind energy is being wasted because the energy changes to suddenly for integration into the grid, as much as fifteen percent can be wasted per month (Koroneos 652). If these wind generators could be augmented with electrolysis units that could produce hydrogen with the excess energy then the efficiency of both the electric grid and the wind generators would increase. Though there are Cook 4 some obstacles to making this plan a reality. First we need to invest in short-term wind forecasting. This is to be able to predict the energy output of the wind turbines ahead of production. This will help to keep production at the maximum energy production possible. Another issue that needs to be overcome is placement. We need to find and exploit locations near large population centers. This will help lower the loss of electricity over distance due to line loss allowing higher efficiency of the system. When we overcome these two problems it will allow the production of wind energy and hydrogen to be more efficient. How would we integrate electrolysis into the energy grid? The most efficient way would be to control the process by computer, allowing all unneeded electricity to be used to create pure hydrogen. With the hydrogen we have two options, either store it on location for use in low wind situations, or high energy demands, or compress it and sell it to gas companies for use in industries and green technology. Each option has its own strengths and weaknesses. Option 1 The first option of storing the hydrogen for later energy production to the grid through a fuel cell, this will greatly improve the consistency of wind power sources. This is because the percent of energy used to separate the hydrogen will be able to be turned back into electricity when the grid has need of it, making it possible to give off 100% of the potential of the wind turbine in little or no wind. Once such a system is installed, wind energy- with hydrogen storage- will be able to increase from the current ten percent maximum production to over thirty percent for wind energy in the electric grid (Koroneos 650). Due to the possibility of long droughts of windlessness, perhaps a week or more, it would be unwise to use wind as the major source of energy in a large electric grid in most areas. But for isolated areas, with high amounts Cook 5 of wind it could be a major source of free and clean energy, without the hassle of transportation of raw energy sources. Option 2 The second option would be to split the elements using electrolysis then compressing the hydrogen into containers for later sell to companies as a raw fuel source. This option will become very important in later years as our transportation turns from oil to alternative energy sources, the chief among them hydrogen. This option is the most economical and the only feasible option at this time due to prices of hydrogen and electricity. This does not mean we stop thinking about other options, or stop trying to lower costs of production to make consistent wind a viable option in the near future. Both of these options require the splitting of water into elemental components making both H2 and O2. As explained earlier an electrolysis unit would be used to separate the elements. The current efficiency of an electrolysis unit is about sixty seven percent, assuming that a large unit is used and that it is allowed to run for long periods of time (Koroneos 654). Yet this is nearly double that of the efficiency of a coal or gas fired power plant. With the addition of heat capturing products we could improve the efficiency of the electrolysis of water even higher, theoretically to over eighty percent (Bontrager). Then the opposite reaction of turning pure H2 and O2 into water and electicity has an efficiency of eighty three percent, again much higher than current energy sources (Bontrager). Implantation The big question is how are we going to make this work, both now and in the future? The first factor to be dealt with is where to place the wind farms to optimize energy capture. The Cook 6 Department of Energy (DoE) has conducted country wide research to answer this problem. As seen in the picture below is in the upper mid-west. This would work great if we had large population centers in the same area; instead the majority of the population of the United States is on the East and West coast. The most economical idea would be to use the wind energy near the largest energy need, near cities, and what could not be produced locally would be imported from regions with high production and low demand. In low wind areas, like Arizona, and the south eastern United States most of the energy would have to be imported, perhaps from the upper mid-west and the Pacific North West. In those locations the excess wind energy would be turned into hydrogen to be stored and shipped all over the nation, firstly as a transportation energy source to power fuel cell vehicles, and second in fuel cell power plants. Such area as the Pacific North West and the upper mid-west Cook 7 would have wind farms using the option 2 discussed above with a nominal reserve for windless days. This idea of using wind to power our electric grid as well as our car, trucks, and other form of transport is not a breakthrough in science; it has been in the minds of scientists all over the world for decades. It is just with the new consciousness of a more caring populace that has made this option a possible future. With a more efficient power grid, and an economical and sustainable way of storing the unused clean energy we have the opportunity to slow and even reverse global climate change through the reduction and eventual elimination of greenhouse gasses. When this happens, with wind and other sources of electricity being used responsibly and to their maximum efficiency, along with more efficient vehicles and energy conscious public, this country can become a model of energy sustainability in a bright and stable future. Cook 8 Works Cited Bontrager, Jordan Bontrager. “Hydrogen Fuel as a Replacement for Fossil Fuels.” Physics Student Research Projects. http://old.hesston.edu/academics/faculty/nelsonk/ 2009/hfuelsource-bontrager/home.html (accessed October 7, 2011). Deal, Walter F. "Wind Power: An Emerging Energy Resource." Technology & Engineering Teacher 70, no. 1 (September 2010): 9-15. Academic Search Premier, EBSCOhost (accessed September 23, 2011). Koroneos C., Katopodi E. “Maximization of Wind Energy Penetration with the use of H2 Production-An Exergy Approach.” (2011) Renewable and Sustainable Energy Reviews, 15 (1), pp. 648-656. "Low-Cost Catalyst for Hydrogen Production." Advanced Materials & Processes 169.1 (2011): 10. Academic OneFile. Web. 24 Sep. 2011. “News and Information About Wind Generator Technologies and Innovations.” Wind Turbines. http://www.alternative-energy-news.info/technology/wind-power/windturbines/ (accessed September 23, 2011). O. Ilinich, et al. "NEW MATERIAL NEEDS FOR HYDROCARBON FUEL PROCESSING: Generating Hydrogen for the PEM Fuel Cell." Annual Review of Materials Research 33, no. 1 (August 2003): 1-27. Academic Search Premier, EBSCOhost (accessed September 23, 2011).