Fuel Cell Education
The History of Fuel Cells:
Sir William Grove first demonstrated the technology behind fuel cells in 1839. The gas battery, later named the fuel cell, reversed the well-understood principal of electrolysis to generate an electrical current. Grove's invention was largely a curiosity as the age was captivated by the horseless carriage and the large reserves of petroleum that were being discovered. Fuel cells remained in obscurity until 1960 when the upstart government agency, The National Aeronautic and Space Administration (NASA), began looking for a practical power source for extended missions to space. Through research and development sponsored by NASA and private industry, the fuel cell is poised to become a replacement for the internal combustion engine and impact the utility industry by making energy cleaner, cheaper and portable.
How Fuel Cells Work:
Fuel cells generate electricity through an electrochemical reaction, known as reverse electrolysis. This reaction combines hydrogen and oxygen to form water vapor, heat and electricity. All three of the by-products of this reverse electrolysis reaction can be further utilized by the fuel cell system. Waste heat can be utilized for space heating and cooling. The water vapor can be captured and used as the feedstock for additional hydrogen and the electricity is channeled into an external circuit where it is used by any electrical appliance.
The benefits of Fuel Cells
Fuel Cells achieve high fuel efficiencies while emitting extremely low emissions.
Fuel cells operate on a wide variety of fuels, utilize electrochemical reactions and contain no moving parts. These features make them simple to operate, quiet and extremely reliable.
One advantage of fuel cells is their fuel flexibility. With the proper reforming technology, fuel cells can extract hydrogen from a wide variety of currently available fossil fuels (e.g. natural gas, methanol, coal, etc.). From fossil fuels, fuel cells utilize one natural element as their fuel, hydrogen, the most abundant element on Earth. In addition to fossil fuels, hydrogen can be generated renewably from water and other photobiological means.
There are four main types of fuel cells distinguished by the electrolyte used in the individual cells. The different types of fuel cells are; polymer electrolyte membrane or proton exchange membrane (PEM), molten carbonate (MCFC), phosphoric acid (PAFC) and the solid oxide fuel cell (SOFC).
Residential Fuel Cells:
In a residential fuel cell system there are three main components. The source of hydrogen, the actual fuel cell stacks and the power condition unit. The hydrogen can either be reformed from fossil fuels (i.e. natural gas, propane, etc?) or the unit can be coupled to a renewable energy source and generate hydrogen through electrolysis of water. The fuel cell stack is thecomponent, which converts the hydrogen and oxygen into electricity, water vapor and heat. The last piece is the power conditioner. This inverts the DC current from the fuel cell into AC current that mosthousehold appliances operate on.
Many factors enter into what your actual energy savings will be. These factors include; individual electricity consumption, geographic location, the particular utility, if utilizing a reformer the price of natural gas or propane, the avoided costs of installing lines to your residence when located in an off-grid area, etc.
The ability to sell electricity back into the grid depends on the geographic location of the unit. Many states have net metering laws, which allow qualified customers to sell surplus electricity back to the grid. Individual states vary on the amount of electricity each individual is allowed to sell so local laws and ordinances should be researched.
Direct Methanol Fuel Cells:
Direct-methanol fuel cells or DMFCs are a subcategory of PEM fuel cells where, the fuel, methanol, is not reformed, but fed directly to the fuel cell. Storage of methanol is much easier than that of hydrogen because it does not need to be done at high pressures or low temperatures, as methanol is a liquid from -142.6 °F to 148.5 °F). Additionally, the energy density of methanol is much higher than that of highly compressed hydrogen.
The efficiency of direct-methanol fuel cells is low due to the high permeation of methanol through the membrane, which is known as methanol crossover, and the dynamic behavior is sluggish. Other problems include the management of carbon dioxide created at the anode. Current DMFCs are limited in the power they can produce, but can still store a high amount of energy content in a small space. Basically, DMFC’s can produce a small amount of power over a long period of time. This makes them ill-suited for powering vehicles, but ideal for consumer goods that do not require high power and high storage such as cell phones, laptops, or digital cameras.
Methanol is toxic and flammable. However, the International Civil Aviation Organization's (ICAO) Dangerous Goods Panel (DGP) voted in November 2005 to allow passengers to carry and use micro fuel cells and methanol fuel cartridges when aboard airplanes to power laptop computers and other consumer electronic devices.
Fuel Cells Verses Other Renewable Energies:
When a solar or wind system is coupled with an electrolyzer, the fuel cell system provides a completely renewable source of electricity. By generating hydrogen with a renewable system, the hydrogen becomes a storage medium for the energy contained in the captured sunlight or wind..
Automotive Batteries Verses Fuel Cells:
Vehicles powered by fuel cells combine the attractive advantages of battery-powered cars and the convenience of an internal combustion engine. Fuel cells operate quietly and are zero to low emissions, comparable to a battery-powered vehicle. Fuel cell powered vehicles offer the range, power, responsiveness and rapid fueling that the internal combustion engine provides. Unlike battery-powered cars, fuel cells do not require lengthy recharge times. The batteries used in automobiles are extremely heavy which limits the vehicles range and capacity. The batteries are also composed of toxic materials and have a limited lifetime and must be recycled. Fuel cell vehicles operating on pure hydrogen produce only water vapor and heat as emissions while fuel cells reforming fossil fuels into hydrogen would be classified as ultra-low emission vehicles.
The Future of Fuel Cells:
In the future, fuel cells couldplay an increasing roll in everyday life. Fuel cell powered cars and trucks will be available, emitting nothing more than harmless water vapor. Fuel cells will find their way into portable devices such as cell phones and laptop computers. Homes and office buildings may have a fuel cell that replaces a conventional furnace, providing heat and electricity free from the disruptions associated with the utility's electric grid. Most of the companies planning to manufacture fuel cells are still in the research and development stage of production. Once their systems satisfy the manufacturers' stringent requirements for performance and safety, the fuel cell systems will be available to the general public.
Government Support of Fuel Cells:
By supporting the research and development of fuel cells, the United States government is developing clean energy sources for our future while strengthening our country’s competitiveness on the world energy market. Many governmental departments, including the Department of Defense, the Department of Energy, Department of Transportation, etc. have fuel cell programs under development.. All of these programs are leading towards the commercialization of fuel cell technology through partnering with private industry. The Federal Government supports research and development through monetary contributions towards research that is considered risky by industry and by creating the initial markets for expensive new technology. For example, the Climate Change Fuel Cell program provides cost sharing regarding the purchase of a fuel cell system. Hydrogen and fuel cells realize only a fraction of the subsidies that the nuclear and fossil fuel industries receive each year.
Japan, Germany and Canada are all intensively developing fuel cell technology in their respective countries. Many of the manufacturers located in these countries enjoy governmental support that far surpasses what the United States Government is providing at home. These countries realize that fuel cells and hydrogen are the most likely replacement for our current energy system and with this in mind, they are trying to develop future industries today.
By supporting fuel cell development, the United States Government will increase the opportunities to strengthen our national energy security, improve environmental conditions and help develop an industry. The United States is dependent on politically unstable and unfriendly regions of the globe for its supply of oil. Currently, the United States imports 50% of its oil and, according to the Department of Energy, this number is expected to grow to 65% by 2020. Fuel cells, with their characteristic fuel flexibility, allow the United States to dramatically reduce its dependence on foreign energy sources and reduce its unbalanced foreign trade debt. By eliminating or greatly reducing the emissions associated with fossil fuels, a noticeable improvement in the environmental conditions in many major metropolitan areas will occur. This will lead to a reduction of pollution-related medical conditions and a dramatic increase in the quality of life for residents of these areas. These two benefits combine to form an incalculable monetary impact.. Fuel cells and related industries can expand and improve the United States economy by creating new jobs in fuel cell manufacturing, sales, service and hydrogen production and storage.
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