You are looking for a new car (about 100 kW nominal power) with the best possible energy efficiency. Which of the engine options should you choose solely based on the engine efficiency?Image: Wikimedia commons, CC BY-SA 4.0.

Question

BlackTom AI · Accepted Answer

Question restatement: You are looking for a new car (about 100 kW nominal power) with the best possible energy efficiency. Which of the engine options should you choose solely based on the engine efficiency?

Option a: Gas turbine. Gas turbines in automotive use tend to have relatively high power-to-weight and fast response, but their thermal efficiency is typically not as high as modern fuel cell systems when evaluated in a comparable automotive cycle. They also suffer from high fuel consumption at part load and require complex accessories, which reduces overall energy efficiency in a passenger car context. In short, when judging engine efficiency in a car, a gas turbine generally does not outperform a fuel-cell system.

Option b: Gas engine. A conventional internal combustion engine (gasoline or diesel) achieves decent performance, but its peak cycle efficiency is limited by combustion chemistry, friction, heat losses, and throttling. Real-world automotive gas engines often operate with overall efficiency significantly lower than that of fuel cells, especially when considering the entire drivetrain. This makes them less energy-efficient than fuel cells for the same peak power rating.

Option c: Fuel cell. A fuel cell converts stored chemical energy directly into electrical energy with relatively high efficiency, particularly when considering the electric drivetrain and regenerative aspects of modern vehicles. When evaluating engine efficiency alone, fuel cells typically provide higher electrical efficiency than internal combustion engines or gas turbines, leading to lower fuel consumption for the same customer-perceived performance in a car of this power class. The account of losses (air operations, cooling, parasitic loads) is often more favorable for fuel cells in this comparison, which is why fuel cells are commonly cited as the most energy-efficient option among the three presented in this context.

Additional considerations: While this question focuses on engine efficiency in isolation, real-world choice also depends on fuel type, fueling infrastructure, cost, maintenance, and system integration. The analysis here isolates efficiency to compare the intrinsic conversion efficiency of each option, not the total life-cycle or user experience. In other words, fuel cells tend to have the best intrinsic efficiency among the three options for a ~100 kW power level, when judged purely on how effectively each option converts chemical energy to usable electrical energy for propulsion.

Climate Action - PtX X-to-power

You are looking for a new car (about 100 kW nominal power) with the best possible energy efficiency. Which of the engine options should you choose solely based on the engine efficiency?Image: Wikimedia commons, CC BY-SA 4.0.

View Explanation

Log in for full answers

Similar Questions

You are looking for a new car (about 100 kW nominal power) with the best possible energy efficiency. Which of the engine options should you choose solely based on the engine efficiency?Image: Wikimedia commons, CC BY-SA 4.0.

In a consumer society, many adults channel creativity into buying things

Economic stress and unpredictable times have resulted in a booming industry for self-help products

People born without creativity never can develop it

A product has a selling price of $20, a contribution margin ratio of 40% and fixed cost of $120,000. To make a profit of $30,000. The number of units that must be sold is: Type the number without $ and a comma. Eg: 20000

Which of the following statement regarding cost is correct:

Under the assumptions used in cost-volume-profit analysis, as the activity increases:

The CVP and break-even analysis are supported by a range of important assumptions. Which of the following is not an assumption of the CVP:

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler