Which statement most accurately captures the relative efficiency of hydrogen fuel cells compared with fossil fuel engines?

Which statement most accurately captures the relative efficiency of hydrogen fuel cells compared with fossil fuel engines?

• A. Hydrogen fuel cells up to 60% efficiency; fossil engines less than 30%.
• B. Hydrogen fuel cells up to 90% efficiency; fossil engines 70%.
• C. Hydrogen fuel cells 40% efficiency; fossil engines 60%.
• D. Both convert energy at about the same efficiency.

Answer: (A)

Hydrogen fuel cells convert chemical energy directly into electricity through an electrochemical process, which is inherently more efficient at turning fuel energy into usable electrical power than burning fuel in an engine and then converting that heat into motion. In practical fuel-cell systems, electrical efficiency commonly falls around 50–60%, with some upper-range stacks approaching that level. By contrast, fossil-fuel internal combustion engines lose a lot of energy as heat, and typical real-world efficiencies sit around the 20–30% range for converting chemical energy of gasoline or diesel into useful work. So the statement that hydrogen fuel cells can reach up to about 60% efficiency while fossil engines are below about 30% best captures the relative difference. The other options either overstate hydrogen-cell efficiency, understate it, or claim the two are about the same, which isn’t accurate given how these conversion processes work.

Hydrogen fuel cells convert chemical energy directly into electricity through an electrochemical process, which is inherently more efficient at turning fuel energy into usable electrical power than burning fuel in an engine and then converting that heat into motion. In practical fuel-cell systems, electrical efficiency commonly falls around 50–60%, with some upper-range stacks approaching that level. By contrast, fossil-fuel internal combustion engines lose a lot of energy as heat, and typical real-world efficiencies sit around the 20–30% range for converting chemical energy of gasoline or diesel into useful work.

So the statement that hydrogen fuel cells can reach up to about 60% efficiency while fossil engines are below about 30% best captures the relative difference. The other options either overstate hydrogen-cell efficiency, understate it, or claim the two are about the same, which isn’t accurate given how these conversion processes work.