Fuel Cell

The Invention of the Fuel Cell Sir William Grove invented the first fuel cell in 1839. Grove knew that water could be split into hydrogen and oxygen by sending an electric current through it (a process called electrolysis). He hypothesized that by reversing the procedure you could produce electricity and water. He created a primitive fuel cell and called it a gas voltaic battery. After experimenting with his new invention, Grove proved his hypothesis. Fifty years later, scientists Ludwig Mond and Charles Langer coined the term fuel cell while attempting to build a practical model to produce electricity.

Fuel cells have emerged as one of the most promising technologies for the power source of the future. The fuel cell is an electrochemical device that converts energy into electricity and heat without combustion. In principle, a fuel cell operates like a battery. Unlike a battery, a fuel cell does not run down or require recharging. It will produce energy in the form of electricity and heat as long as fuel is supplied.

Fuel cells can promote energy diversity and a transition to renewable energy sources. Hydrogen, the most abundant element on Earth, can be used directly. Fuel cells can also utilise fuel containing hydrogen, including methanol, ethanol, natural gas and even gasoline or diesel fuel, but requires a "fuel reformer" that extracts the hydrogen.

In 2003, President Bush announced a pr­ogram called the Hydrogen Fuel Initiative (HFI) during his State of the Union Address. This initiative, supported by legislation in the Energy Policy Act of 2005 (EPACT 2005) and the Advanced Energy Initiative of 2006, aims to develop hydrogen, fuel cell and infrastructure technologies to make fuel-cell vehicles practical and cost-effective by 2020. The United States has dedicated more than one billion dollars to fuel cell research and development so far.

Applications for Fuel Cells

Residential
Fule cells are ideal for power generation, either connected to the elctric grid to provide supplemental power and backup assurance for critical areas, or installed as a grid-independant generator for on-site service on areas that are inaccessable by power lines. Since fuel cells operate silently, they reduce noise pollution as well as air pollution and the waste heat from a fuel cell can be used to provide hot water for a home.

Transport
All major automotive manufacturers have fuel cell vehicle either in development or in testing stage - Honda, Toyota, GM, Ford, Hyundai, Volkswagen etc. It is estimated that fuel call vehicles will be commercialized in very near future .However there are significant technical barriers such as hydrogen storage, fuel structure, cost/affordability, reliability/durability and air/water/thermal management.

Portable Power
Fuel cell will chage the telecommuting world, powering cellular phones, laptops for hours longer than batteries. Other applications for micro fuel cells include pagers, video recorders, portable power tools and low power remote devices such as hearing aids, smoke detectors, burglars alarms, and meter readers.

Landfills/Wastewater Treatment
Fuel cells currently operate at landfills and wastewater treatment plants across the world proving themselves as valid technology for reducing emissions and generating power from the methane gas they produce. Toshiba has installed fuel cells that run on waste gases and plans to expand efforts to sell fuel cell systems that run on gas sewage sludge. Using fuel cells to recover energy from landfill and other waste gases is proving to be a viable method and is potentially one of the cleanest and most cost-effective energy conversion technologies.

Advantages of Fuel Cells

Environmental Benefits
Fuel cells are considered an excellent alternative energy resource from the environmental point of view. fuel cells are quiet and produce negligible emissions of pollutants.

Efficiency
Different types of fuel cells have varied effeciencies, ranging from 40% to 60%. Alkaline fuel cells can even achieve power generating efficiencies of up to 70%.

Fuel Availability
The primary fuel source for the fuel cell is hydrogen which can be obtained from natural gas, coal gas, methanol and other fuels containing hydrocarbons. More importantly, electrolysis (splitting of water molecules) can produce pure hydrogen.

In short, why Fuel Cell?

Fuel cells generate electrical power quietly and efficiently, without pollution. Dissimilar to power sources that derived from fossil fuels, the by-products from an operating fuel cell are heat and water.

Fuel Cell Vehicle Efficiency:

If the fuel cell is powered with pure hydrogen, it has the potential to be up to 80-percent efficient. That is, it converts 80 percent of the energy content of the hydrogen into electrical energy. However, we still need to convert the electrical energy into mechanical work. This is accomplished by the electric motor and inverter. A reasonable efficiency of the motor/inverter is about 80 percent.
Therefore we have 80-percent efficiency in generating electricity, and 80-percent efficiency converting it to mechanical power.
That gives an overall efficiency of about 64 percent.

Honda’s FCX concept vehicle reportedly has 60-percent energy efficiency.

If the fuel source isn’t pure hydrogen, then the vehicle will also need a reformer to turn hydrocarbon or alcohol fuels into hydrogen. They generate heat and produce other gases besides hydrogen. They use various devices to try to clean up the hydrogen, but even so, the hydrogen that comes out of them is not pure, and this lowers the efficiency of the fuel cell.

Because reformers impact fuel cell efficiency, DOE researches have decided to concentrate on pure hydrogen fuel-cell vehicles, despite challenges associated with hydrogen production and storage.

Note: Gasoline-Battery powered vehicles have an overall efficiency of 26-30%.
Calculation: The whole cycle: the efficiency of an electric car is 72% for the car, 40% for the power plant (that's 40 percent of the fuel required by the power plant was converted into electricity) and 90 percent for charging the car. That gives an overall efficiency of 26 percent.

Fuel Cell Problems

Cost

In the economy perspective, many of the component pieces of a fuel cell are costly. For PEMFC (Proton Exchange Membranes Fuel Cell), precious metal catalysts (usually platinum), gas diffusion layers, and bipolar plates make up 70 percent of a system's cost
[Source: Basic Research Needs for a Hydrogen Economy].
In order to be competitively priced (compared to gasoline-powered vehicles), fuel cell systems must cost $35 per kilowatt. Currently, the projected high-volume production price is $110 per kilowatt [Source: Testimony of David Garman].

Durability

Researchers must develop PEMFC membranes that are durable and can operate at temperatures greater than 100 degrees Celsius and still function at sub-zero ambient temperatures. A 100 degrees Celsius temperature target is required in order for a fuel cell to have a higher tolerance to impurities in fuel. Because you start and stop a car relatively frequently, it is important for the membrane to remain stable under cycling conditions. Currently membranes tend to degrade while fuel cells cycle on and off, particularly as operating temperatures rise.

Hydration

Because PEMFC membranes must by hydrated in order to transfer hydrogen protons (electrolyte), researches must find a way to develop fuel cell systems that can continue to operate in sub-zero temperatures, low humidity environments and high operating temperatures. At around 80 degrees Celsius, hydration is lost without a high-pressure hydration system.

The SOFC (Solid oxide fuel cell) has a related problem with durability. Solid oxide systems have issues with material corrosion. Seal integrity is also a major concern. The cost goal for SOFC is less restrictive than for PEMFC systems at $400 per kilowatt, but there are no obvious means of achieving that goal due to high material costs. SOFC durability suffers after the cell repeatedly heats up to operating temperature and then cools down to room temperature.

Infrastructure

In order for PEMFC vehicles to become a viable alternative for consumers, there must be a hydrogen generation and delivery infrastructure. This infrastructure might include pipelines, truck transport, fueling stations and hydrogen generation plants. It is hoped that the development of a marketable vehicle model will drive the development of an infrastructure to support it.

Storage, Delivery & Safety

The development is highly limited by the hurdles pertaining hydrogen storage due to its low energy density and safety issue about the hydrogen as its very combustible!

Also, PEMFC systems have become lighter and smaller as improvements are made, they still are too large and heavy for use in standard vehicles.

Wrap-up:

Fuel Cell will make its significant contribution in future phasing out the Fossil fuel Economy!!