What environmental factor can affect CNG operation significantly?

Extreme cold weather can significantly affect the operation of CNG (Compressed Natural Gas) systems. In low temperatures, the fuel can experience reduced pressure, which directly impacts performance. CNG relies on maintaining specific temperature and pressure conditions to function optimally in engine systems. When temperatures drop significantly, the density and pressure of CNG may decrease, leading to inadequate fuel delivery to the engine. This can cause suboptimal combustion, resulting in decreased power output and efficiency.

In contrast, options like high humidity and excessive sunlight have less direct influence on the performance of CNG systems. While they may impact combustion efficiency to a degree, they do not typically result in the same significant challenges posed by extreme cold. Wind speed similarly does not create enough of an impact on the operational parameters of CNG systems. Thus, extreme cold weather stands out as a critical environmental factor that can hinder CNG operation.