Which feature is associated with hydrogen fuel cells?

Hydrogen fuel cells are associated with high cost, medium efficiency, and low environmental impact. The technology required to produce, store, and utilize hydrogen can be quite sophisticated and expensive, which contributes to the high costs associated with hydrogen fuel cells. However, in terms of efficiency, hydrogen fuel cells do not convert energy as efficiently as some renewable energy sources, though they still surpass traditional combustion engines significantly. One of the most significant benefits of hydrogen fuel cells is their low environmental impact, as they produce only water vapor as a byproduct when hydrogen is consumed, making them a clean energy source.

In contrast to this, lower-cost technologies often come with higher emissions or greater environmental challenges, and technologies that promise high efficiency frequently do not have the same clean outcomes. Thus, the characteristics of hydrogen fuel cells that denote their high cost and relatively low environmental impact are pivotal in defining their role in sustainable energy practices.