Hydrogen Fuel CellsHydrogen Fuel Cellsas an Alternative Automobile as an Alternative Automobile

Power SourcePower Source

By Kenneth NoyceBy Kenneth NoycePhysics 3150Physics 3150

Energy and SustainabilityEnergy and Sustainability

Questions to be answeredQuestions to be answered

• What is a Fuel Cell?What is a Fuel Cell?

• How does a Fuel Cell work?How does a Fuel Cell work?

• How can a Fuel Cell be used in a car?How can a Fuel Cell be used in a car?

• What are the advantages of a Fuel Cell?What are the advantages of a Fuel Cell?

• What are the disadvantages of a Fuel What are the disadvantages of a Fuel Cell?Cell?

• How efficient would a Fuel Cell car be?How efficient would a Fuel Cell car be?

What is a Fuel Cell?What is a Fuel Cell?

• An electrochemical conversion deviceAn electrochemical conversion device

A better known electrochemical A better known electrochemical conversion device is a battery.conversion device is a battery.

A Fuel cell is a thermodynamically A Fuel cell is a thermodynamically open system whereas a Battery is a open system whereas a Battery is a closed system.closed system.

What is a Fuel Cell?What is a Fuel Cell?

A fuel cell such as A fuel cell such as the one pictured to the one pictured to the right converts the right converts chemical potential chemical potential energy stored in the energy stored in the fuel into electrical fuel into electrical energy through a energy through a process of oxidation process of oxidation of the fuel.of the fuel.

How does a Fuel Cell work?How does a Fuel Cell work?

1. Hydrogen fuel is broken into positive 1. Hydrogen fuel is broken into positive hydrogen ions and Negative electrons.hydrogen ions and Negative electrons.

2. The hydrogen ions pass through an 2. The hydrogen ions pass through an electrically insulating membrane which electrically insulating membrane which forced the electrons through an external forced the electrons through an external circuit.circuit.

3. The Hydrogen ions and electrons then react 3. The Hydrogen ions and electrons then react with oxygen to form water as a byproduct. with oxygen to form water as a byproduct.

How does a Fuel Cell work?How does a Fuel Cell work?

How can a Fuel Cell power a How can a Fuel Cell power a car?car?

Currently there are 2 Currently there are 2 types of automobile types of automobile engines, Internal engines, Internal Combustion, and Combustion, and Electrical. A fuel cell Electrical. A fuel cell can be used to power can be used to power an electrical engine an electrical engine similarly to how similarly to how gasoline is used to gasoline is used to power an internal power an internal combustion engine.combustion engine.

How can a Fuel Cell power a How can a Fuel Cell power a car?car?

• Car would have a hydrogen tank Car would have a hydrogen tank rather than a gas tank.rather than a gas tank.

• The chemical energy stored in the The chemical energy stored in the hydrogen would be converted into hydrogen would be converted into electrical energy in the fuel cell.electrical energy in the fuel cell.

• The electrical energy produced by The electrical energy produced by the fuel cell would power the car’s the fuel cell would power the car’s electric motor.electric motor.

What are a Fuel Cell’s What are a Fuel Cell’s Advantages?Advantages?

Emissions:Emissions:

Water is the only emission Water is the only emission produced by produced by a Fuel Cella Fuel Cell

Fuel availability:Fuel availability:

Hydrogen comes from Hydrogen comes from electrolysis of electrolysis of water which is a water which is a readily available readily available substance.substance.

What are a Fuel Cell’s What are a Fuel Cell’s advantages?advantages?

Reusability:Reusability:

A fuel cell has an extremely long life A fuel cell has an extremely long life unlike unlike the batteries used to power the batteries used to power current electrical current electrical carscars

Motor Efficiency:Motor Efficiency:

Electric motors can easily achieve Electric motors can easily achieve 90% 90% efficiency whereas internal efficiency whereas internal combustion combustion engines are typically only engines are typically only 30% efficient.30% efficient.

What are a Fuel Cell’s What are a Fuel Cell’s disadvantages?disadvantages?

Cost:Cost:

Fuel Cells are currently very expensive Fuel Cells are currently very expensive ($2000-$20000/kW) due to both their ($2000-$20000/kW) due to both their platinum content and production costs.platinum content and production costs.

Weight: Weight:

Fuel cells are much heavier than Fuel cells are much heavier than batteries with the same power output.batteries with the same power output.

What are a Fuel Cell’s What are a Fuel Cell’s disadvantages?disadvantages?

Operating Temperature:Operating Temperature:

Most Fuel Cells can’t operate at Most Fuel Cells can’t operate at temperatures below freezing.temperatures below freezing.

Energy content of Hydrogen:Energy content of Hydrogen:

Hydrogen production requires Hydrogen production requires more more energy than is stored in the energy than is stored in the hydrogen hydrogen making it an energy making it an energy storage fuel.storage fuel.

How efficient is a Fuel Cell?How efficient is a Fuel Cell?

• Fuel Cells range from 50% to 80% Fuel Cells range from 50% to 80% efficient depending on the operating efficient depending on the operating temperature, and the current drawn temperature, and the current drawn from the fuel cell. from the fuel cell.

• Hydrogen production through Hydrogen production through electrolysis can obtain 80% electrolysis can obtain 80% efficiency.efficiency.

• Electrical motors can attain 95% Electrical motors can attain 95% efficiency.efficiency.

How efficient is a Fuel Cell How efficient is a Fuel Cell car?car?

The maximum theoretical efficiency of a The maximum theoretical efficiency of a Fuel Cell powered vehicle from hydrogen Fuel Cell powered vehicle from hydrogen production to driving assuming 10% losses production to driving assuming 10% losses due to friction is:due to friction is:

μμ = .8 x .85 x .95 x .9 = .59 = 59% efficient = .8 x .85 x .95 x .9 = .59 = 59% efficient

The actual efficiency would be less than The actual efficiency would be less than this, but would still be much higher than this, but would still be much higher than the average 10% efficiency of most cars the average 10% efficiency of most cars on the road today. on the road today.

ReferencesReferences

www.wikipedia.orgwww.wikipedia.org

www.bp.comwww.bp.com

www.hydrogenhighway.ca.govwww.hydrogenhighway.ca.gov

www.shell.comwww.shell.com

Questions?Questions?