The advent of internal combustion engines (I. C. E's) has limited the application of steam engines today. I. C. E's are compact and more efficient than steam engines. However their inherent problem is the emission of hazardous gases, which is why engineers are looking for better options.

The sterling engine eliminates the problems of steam engines and produces no emissions.
I believe this is an area with the potential for future energy supply. Thanks for the insight. Keep it rolling.