I found a series of videos on youtube a while back, a set of training videos for people working in steam turbine plans, which really cemented in my head the rea

I found a series of videos on youtube a while back, a set of training videos for people working in steam turbine plans, which really cemented in my head the reasons why this is the case. For example: the final stages of a steam condensing turbine are actually operating under vacuum relative to atmospheric pressure. To start the turbine a vacuum pump first removes the the air from the turbine. After steams works its way through the turbine it is cooled by feed water (which is then used in the boiler) reducing it's volume by about 1000 times maintaining the vacuum. An ICE on the other hand expels a good portion of the input energy as hot exhaust gasses several PSI above atmospheric pressure.