An automotive fuel cell system is more efficient than an internal combustion engine at:

1. maximum power only

2. partial load only

3. any load

An automobile needs to store approximately:

1. 0.5kg of hydrogen

2. 5kg of hydrogen

3. 50kg of hydrogen

One kilogram of hydrogen pressurized at 200 bar takes approximately:

1. 6 liters

2. 16 liters

3. 60 liters

A pressurized fuel cell system with a turbine/expander:

1. is more efficient than a low-pressure system

2. has about same efficiency as a low-pressure system

3. is less efficient than a low-pressure system

The economics of fuel cells for stationary generation of electricity depends on:

1. a difference in price between electricity and natural gas

2. a ratio of prices of electricity and natural gas

3. price of natural gas only

Capacity factor is:

1. number of hours a fuel cell system operates divided by 8760 (number of hours in a year)

2. a ratio between kilowatthours of electricity produced in a year and kilowatthours that would have been produced if the system operated at full power the entire year

3. a ratio between the fuel cell average power and average power required by the load

Annual average efficiency of a fuel system:

1. is always smaller than the efficiency at nominal power

2. is always higher than the efficiency at nominal power

3. may be smaller or larger depending on how the system is operated throughout the year

What would be the effect of an increase in the price of natural gas on the economics of a fuel cell system that is used in cogeneration (heat and...